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This is a 1991 Volvo 245 with 145,000 miles, automatic, California car.
BACKGROUND: In 2017 a shop replaced the timing belt, water pump, accessory belts, and the three front engine seals. Two years later in August 2019 there was a sudden and large oil leak which turned out to be mostly from the front crankshaft seal and the front seal plate. In recent BB submissions starting in October 2019, I asked questions about leaking front oil seals and learned that excess crankcase pressure can cause them to leak. Thinking back, I recalled that several years prior, the rear camshaft seal came out and fell to the ground. Naively, I just popped the old worn seal back in place. Because it was a loose fitting seal, I stuffed a mechanic's wiping rag between it and the firewall to help keep it in place. A week later, I bolted in a metal half-plate from IPD so the seal could not pop out again. That event likely was the first indication of a problem with crankcase pressure. There has been no problem or leak in that location since that time. Back to the present. In January 2020, in addition to replacing the water pump and the alternator bushings, I replaced the (Elring) camshaft seal, intermediate shaft seal, crankshaft seal, and seal plate gasket. The "glove test" shows that the engine has excessive crankcase pressure at the oil filler cap. Looking for the cause of the excess pressure, I cleaned the flame trap which was not very dirty and it was not clogged. I checked for a clog in the oil separator box by pouring mineral spirits in the hose below the flame trap. That liquid immediately ran out the drain hole in the oil pan indicating that the oil separator is not clogged. The small vacuum hose from the intake manifold to the flame trap has plenty of suction. The oil dipstick has never popped up. I've driven the car only a few hundred miles since that January repair.
CURRENT SITUATION: Two weeks ago, the leak in the front of the engine returned suddenly with a vengeance. When the engine is running, oil leaks even more than the previous time - most of the engine has a coating of oil (nice and shiny) in addition to the generous amount that drips down to the ground. It appears to be originating from the front crankshaft seal. There is a small amount of oil originating from the front cam seal area, but not sufficient to reach the ground. I plan to remove the drive belts, the timing belt, and the crank pulley to confirm the location of the leak. Meanwhile I did a compression test with the following results:
Cylinder one - 180
Cylinder two - 185
Cylinder three - 185
Cylinder four - 185
The engine was not fully warmed up for the test, nor was the throttle opened. These results would seem to indicate that "blowby" from worn piston rings is not the cause of the excessive crankcase pressure. The spark plugs had been installed about 10 years ago and were black, not tan.
There could be three reasons that I can think of to explain the front crank seal leaking again.
1. a failed seal - not likely
2. improperly inserted seal - a possibility
3. seal blown out by excessive crankcase pressure - a possibility
Though it may be worth a try, I am hesitant to just replace the front seal if it will just blow out again by crankcase pressure. I also do not want to run the risk of the rear crank seal failing from excess pressure. That would be a worse problem. In order to be sure that the new crank seal was installed correctly, I had hoped to find the Volvo approved crank seal installer but have not been able to obtain one. Although, it appears that most front seals are installed without that special tool. The pressure that can be felt putting a hand over the oil filler hole does not seem all that powerful. I have heard of 240 engines that have so much pressure that they cause the dipstick to be pushed up out of the dipstick hole. Mine never did that.
I am not sure what to do next.
QUESTIONS:
1. Based on the results of the compression check does it seem reasonable to conclude that blowby is not causing excess crankcase pressure?
2. Does the crankcase pressure increase with engine speed or load? (I ask this because I checked the engine only at idle)
3. Would a vacuum gauge yield any useful information?
4. Would a leakdown test be worthwhile to perform?
5. Does a leakdown test require special skills, or can a mediocre mechanic competently perform this? Would it be better to choose a Volvo mechanic?
6. Having eliminated the flame trap, the oil separator box, and blowby, what else might be causing the excessive crankcase pressure?
7. Other than pulling up the oil dipstick, is there a way to relieve the excess crankcase pressure by, for example, having a relief device installed somewhere in the upper part of the engine? (I would consider leaving the oil cap off temporarily to see if that might make a difference - but only if I could keep the oil from splashing out and be sure nothing would fall into the engine)
8. Does the fact that the two front crank seal leaks happened suddenly rather than gradually over time give any clue?
9. What do black spark plugs indicate? I have heard that could mean a lean mixture, which in turn can increase crankcase pressure. Any truth to that?
10. The snout of the crankshaft has two very small grooves just about where the soft part of the seal might touch. Can the soft part of the seal wear a small groove? Might that be a cause of seal failure?
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Meanwhile I did a compression test with the following results:
Cylinder one - 180
Cylinder two - 185
Cylinder three - 185
Cylinder four - 185
Good compression results. No guess on oil leak cause.
Unless front engine seals were installed incorrectly by not using a Volvo or other seal press tool as we already discussed at length.
If you use the older orange seals, there exist a set of tools for those.
If you used the newer, thinner viton seals (brown or grey) a different set of seal press tools.
Inspect outer oil seal bore and inner rotating surface for nicks, scratches, and such.
" ... most of the engine has a coating of oil (nice and shiny) in addition to the generous amount that drips down to the ground ...
Your description here suggests risk for engine bay fire and also catastrophic engine failure from engine oil loss.
All I got.
--
Jonathan Harshman Winters III: The Mightiest, Greatest, & Most Powerful North American Comedian & Comedic Actor in Perpetuity!
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I can't imagine why the tool would be any different for different brand seal regardless of the thickness.
I have the Volvo tool but there is nothing special about it- sliding a seal on a properly cleaned and grease shaft isn't problematic.
I clean the shaft and apply a good layer of white lithium to it and the seal. I then tilt the seal and get the bottom edge below the shaft before slowing raising it against the shaft enough to get the space at the top of seal needed to get it started on the shaft.
Once the seal is on the shaft slowly rotate it while pushing it back until it makes contact with the housing. Carefully tap the seal until it gets started into the housing. Use whatever you have that is flat faced and contacts the seal over as much of its surface as possible.
If you had any wear on the shaft be sure that the contact area of the seal is not falling onto that wear area. Calculate that before starting the replacement.
The crank seals fit the housing snugly (unlike a lot of the cam seals I have come across). I wouldn't be concerned about the crank seal protruding somewhat to avoid seating it where the wear area and the seal lip would meet.
Randy
--
Any twenty minute job is just a broken bolt away from a three day ordeal
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Hiya Mr. Starkie!!!!!!!
Sure happy it's Thursday (all day long)! Hope you, yours, everybody and everyone are in the finest of fettles and aces and eights!
The Volvo engine oil seal press tools came in two editions or sets to service the two different editions of the Volvo engine oil seals.
The early set were the orange seal from Victor-Reinz. The seals pressed in the seals straight.
Yet unlike the newer seals and presses, these orange seals did not require that the seal be placed onto the seal press to open up the seal interior side side as you use the threaded nuts to press in the seal. These seals are more robust and thicker so less chance the inner seal tension spring would pop out.
The orange seals are far more tolerant if not pressing them in straight. So you could get away with using a PVC section with maybe a cap and washer and nut, or a flat surface to set the exterior side flush, to press the seal into the bore.
The newer, thinner, dark grey or brown seals made of the viton material are thinner. You may read some may merely press these seals in with finger, PVC, or a flat surface like a wood section. As you are not using the second edition of Volvo engine oil seal presses the seal mounts onto, to open the seal inside diameter, with these thin seals, the interior seal tension spring can pop out as you install it.
Not pressing these viton engine oil seals in straight means a better chance for leaks.
I also like the Permatex sealing compound for the outer seal surface that seals in the bore.
Yet no matter the method whether the bore and shaft rotation surfaces are perfect or nicked, they can leak.
Also, look to the seal carrying plate gasket as these are paper thin and can embrittle in the presence of dino engine oil, age, heat and vibration, and carrying plate retaining hardware torque as the thread gets engine oil lube and heat and vibration after many centuries, oop (!), decades (ha!) can cause the hardware to loosen.
In earlier faof2 threads someplace is an image of the difference between the seal presses, at least for the engine front. There is a large seal press for the rear main crank seal. (I'll find it now in faof2 thread history momentarily if the image link remains live, we hope!)
The Volvo 700-900 FAQ addresses the seal press use for the engine front for the low friction engines. The think orange seals were used in these and than the factory transitioned to the viton seals.
https://www.brickboard.com/FAQ/700-900/EngineSealsBeltsVent.htm#Replacing_Oil_Seals
A terrible smallish image of the viton seal press that you can use with the thick orange seals (so far as I know, I've not tried):
derp ... derp ... derp ... derp ....
This post I replied to faof2. Copy and Paste the link into a new browser tab or window:
https://www.brickboard.com/RWD/volvo/1670531/220/240/260/280/engine_oil_seals_clear_excess_crank_pressure_cause_first.html
In this image, you see the first edition engine oil seal presses for B21 onward.
The two seal presses to the left in the image are for the orange seals.
The far left image is the cam seal and the middle image is for the crank seal to press in the thick orange seals. Do not use these blunt presses for the thin viton seals.
The image to the right is the newer (ha!) front crank seal press for later low friction engines. Yet you can use the viton seals and their presses in any 240 redblock and some other Volvo engines using the same seal.
The images are hosted on Eric Planetman's High Performance Auto Service website.
Hope that helps.
Sorry to go on. Had some super strong earl grey tea in two glasses. Theobromine overload! (Maybe a little caffiene.) Theobromine is the stimulant in tea and chocolate!
Questions?
MacDuffed
--
Jonathan Harshman Winters III: The Mightiest, Greatest, & Most Powerful North American Comedian & Comedic Actor in Perpetuity!
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Thanks, "kittys grey - - -" and Randy for your suggestions. Randy, I am trying to visualize what you are recommending when you write " I then tilt the seal and get the bottom edge below the shaft before slowing raising it against the shaft enough to get the space at the top of seal needed to get it started on the shaft." Any elaboration on that would be helpful. There was a recommendation to pack the inside of the seal with grease to help keep the lip in place. Do you recommend that?
I recall that there were two wear areas on the shaft last time. I guess I will attempt to place the seal such that the lip falls between the two.
I still have no clue as to what is causing the excess crankcase pressure.
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I wish I was an artist and could draw a diagram to illustrate my explanation, but I'm not.
I do fill the back of the seal with grease. However, it may be just chicken soup: it can't hurt but I can't prove that it helps. The idea is to keep the spring seated.
The spring should not be a problem unless you push the lip of the seal towards the front of the seal when trying to install it. Then you are screwed but don't know it because it is not obvious it left its home position.
Once everything is greased and you move to installing the seal on the shaft you have to make sure the lip of the seal remains in the position with the lip pointing towards the engine.
Rather than holding the seal in a vertical position to get it started on the shaft I tilt it slightly off of vertical so the bottom edge of the lip is behind the front edge of the shaft (the seal will be a bit below center of the shaft).
From that positioning if you raise the seal it will depress the lip and in effect make the opening of the seal somewhat larger. You only have to depress the lip with enough pressure against the shaft to make it easy to move to seal towards vertical and it will slip right onto the shaft without catching any of the lip on the leading edge of the shaft. Once the lip is on the shaft you are basically home free.
I then slowly rotate the seal as I push it back until it contacts the housing.
Then tap the front edge of the seal to start seating it in the housing. Once started in just keep working your way around the perimeter to slowly get it into the position you have determined you want for the proper depth.
Randy
--
Any twenty minute job is just a broken bolt away from a three day ordeal
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Thanks Chris and Randy for your thoughts on this problem. I now see a possible solution if your analysis is correct. Let's start with the oil separator. On the FCP EURO website, I looked at the 1991 Volvo oil separator box (Genuine Volvo) with views from several angles. Here is the link:
https://www.fcpeuro.com/products/volvo-pcv-oil-trap-240-740-760-780-940-genuine-volvo-3501160oe
As to the Haynes Manual indicating a "later version" of the oil box, I checked FCP for the correct oil box for two earlier years for the 240 (1983 and 1987). That showed a different part number (1306398) for these earlier models. Here is the link to that part:
https://www.fcpeuro.com/products/volvo-pcv-oil-trap-240-740-760-1306398
So it appears that there was some kind of change between 1987 and 1991. However they both have two ports at the bottom. I do not know what the difference might be.
CHRIS: You described " - - - the breather box with the two ports running down to the crankcase - the vapor port that allows the excess pressure to flow up into the box and the condensed oil return port that actually extends all the way down into the oil sump. When you blow air into crankcase via the top port of the box the air should follow the path of least resistance into the crankcase, then out through the oil fill port. The breather box port that extends clear down into the oil sump should NOT be the path of least resistance. The port that runs into the air space ABOVE the oil level SHOULD be the path of least resistance."
You are saying both ports on the bottom empty into the oil pan, one terminating above the oil level, and the other below the oil level , correct? And that the one terminating below the oil level is allowing air (and the solvent) to pass through, while the other one is blocked, right? That makes a strong case for the oil box being clogged and that removing it and cleaning it is the solution.
RANDY: Your description of cleaning the oil box is helpful. I expect to be doing that some day. I imagine removing the intake manifold will be the difficult part. And your clarification of the manner you use to install the seal is much appreciated.
When I get more time on my hands, I plan to remove the intake manifold and remove and clean the oil box. Other than cleaning the throttle plate and replacing the intake manifold gasket, what else might you recommend while the manifold is off? Should I remove and clean the EGR valve, or just leave it alone?
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I looked at a diagram of the PCV system in the Bentley Manual on page 253-2. It shows that liquid could travel straight down into the oil box at the same time that the pathway for oil vapors could be clogged.
As to removing that box without removing the intake manifold, as a California car, this engine has an EGR valve down there which I've read makes it even more difficult to remove the box. I've never been good at working in tight spaces, and I've already got enough battle scars on my hands.
All of this discussion has got me wondering about a couple of things, which I will pose as questions.
1. Does the term "flame trap" refer just to the gizmo on top that has the insert with holes, or does it refer to the entire assembly going down to and including the oil box?
2. As the diagram referred to above shows, there are two paths inside the oil box. Is there a way to send something down from the top of the flame trap and have it go into the path that the oil vapors travel on their way up?
Given the amount of work involved in removing the oil separator box, I want to try first any easier method of cleaning out the box.
I have another reason to be hesitant to do all that work. This car has "only" 145,000 miles. A mechanic once told me that a car with 200,000 miles and up might be having a problem with blockage, but not one with less mileage that that.
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I looked at the boxes for which you posted the links. I have to tell you that I do not remember the bottom looking like that. Since they are so similar I have to blame my description of an opening in the top and one in the bottom had to have been based on a failing memory- obviously there are two on the bottom.
I wouldn't put off dealing with the crankcase pressure. I had the experience of blowing out a rear main seal far from home. I was new to Volvos and not very experienced in car mechanics. The flame trap on our 76 240 was clogged. It is a long story not to be told here, but it would have been easy to avoid if I had known what I know now.
I said it was easier to remove the intake and it is but it doesn't have to come off. Expose the area as much as you can by removing and throttle body and hoses as well as the idle control motor and see what you think. Do have a Oring to seal things up when replacing it.
What else to do if you remove the intake manifold? Heater hoses for sure.
Randy
--
Any twenty minute job is just a broken bolt away from a three day ordeal
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Let's try again....
Some folks, myself included, have had trouble with the aftermarket seals fitting too loosely at the O.D. I had to redo a cam seal once, and use a tighter fitting seal from the Volvo dealer.
Does your car sit for long periods of time? Is it used primarily for short runs? I'm just wondering if it doesn't get to run fully warmed up enough. Like maybe the rings get stuck when cold. Was the PCV checked when cold or after a good warm up?
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Chris Mullet
Thanks for your comments, Chris. You asked some interesting questions. When I inserted the camshaft seal in January, it was loose in the outside diameter. I packed it with RTV sealant or similar. The crank and intermediate shaft seals were reasonably tight.
Does your car sit for long periods of time? Is it used primarily for short runs? I'm just wondering if it doesn't get to run fully warmed up enough
Normally it does sit for long periods of time. It had been used regularly
for short and longer in-town trips. Now with COVID, I make an early
morning run of one mile, then back an hour later. So now it does not get
fully warmed up. However the problem of excess crankcase pressure pre-
dates COVID.
Like maybe the rings get stuck when cold.
Would the compression test suggest that the rings are not stuck? Is there
a way to know? Would stuck piston rings cause excess crankcase pressure?
Was the PCV checked when cold or after a good warm up?
Not entirely sure what you are asking here. Checking the PVC was done
when the engine was barely warm. Would have been too hot when warmed up.
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You showed some good compression numbers... Assuming your gauge is accurate then the rings must have been seating well at least when you tested them - maybe not so when you checked the PCV and saw positive crankcase pressure. I'm just trying to mentally find a connection between black plugs, clogged PCV, and blown seal.
Can you blow air into the breather box and have it rush, unobstructed, out of the (opened) oil filler port?
When you were checking the PCV, did you poke a skinny wire through the orifice (nipple) where it connects to the intake manifold? If that's clogged the PCV won't work as it should.
BTW, you should be able to check for a functioning PCV system by doing the rubber glove test at the oil filler neck, regardless of whether the engine is hot or not. It will just be "quite warm" when you slip the glove on :)
Is the oil good and clean? How often do you change it?
I've never used the Seafoam product but some people swear by its ability to clean out the engine.
As was previously mentioned you may be running rich. It might not be a bad idea to check the fuel pressure at the injector rail to verify a properly functioning pressure regulator.
Are you getting any fault codes in the OBD? (Just kinda curious.)
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Chris Mullet You are asking good question, and I appreciate that because it gives me an opportunity to expand on what I observed on the car.
COMPRESSION NUMBERS
Whether or not the compression gauge is accurate is unknown. However, I have no reason to suspect it, and the readings seem consistent with the relatively low mileage on the engine and the legendary longevity of this engine. If I get the opportunity, I will use someone else's gauge and see if there is a difference.
BLOWING IN THE PCV SYSTEM
After disconnecting the large hose from the bellows and pinching off the small tube to the intake manifold, I blew into the bellows end of the large hose with the oil cap on. It was hard to blow, like trying to blow up an industrial size balloon, but I got some air in, and when I let go, a small amount of air came back. With the oil cap off, I did the same and got the same result, except that no air came back. This finding strikes me as central to the issue. From my reading , it appears that others find it difficult to blow in when the cap is on, and easier when the cap is off. What has been your experience with this? That was several months ago and I am thinking of doing that again. I will add here that the large and small hose on the top of the flame trap were remarkably clean. The flame trap itself was relatively clean, not at all clogged even though I had only once before cleaned it. As for the orifice on the intake manifold, I removed that and drilled it out to a slightly larger diameter. It gives good suction at idle.
Considerable reading about PVC issues, and the "hard to blow" finding combined with the finding of excess pressure, convinced me that the oil breather box was clogged. I decided not to change out the oil box for a variety of reasons, one of which is that this is a California car which has an EGR valve which makes it difficult to remove the box without removing the manifold. And the aftermarket boxes are of poor quality. So I prepared to clean out the clogged oil separator box by draining the engine oil, leaving the drain plug out, and pouring mineral spirits down the tube below the flame trap until the liquid flowed through readily and no more "gunk" emerged. Surprise - the first two cups of mineral spirits ran right through and flowed out the drain hole in the pan. Nothing was clogging the path of the mineral spirits. That eliminated the oil box as the culprit. Would you agree with that interpretation?
CLEANING OUT THE ENGINE
I am not opposed to cleaning out the engine. I do wonder, though, as to what is meant by "cleaning out the engine". What exactly would be cleaned out? And the part that would be cleaned out, would that be something that was causing excess crankcase pressure? My favorite way of cleaning out is to introduce some ATF into the oil as it is high in detergent. If I believed something like Seafoam would cure this, I would use it. But I'm skeptical of quick fixes.
RUNNING RICH
Unless this might be a cause of excess pressure, I will add that chore to an already long list of things that this car needs.
FAULT CODES
Oh yeah, lots of fault codes over the last few years. Most of them left and didn't return after I cleaned the throttle body several years ago. Occasionally I still get an ignition system (Socket #6) code of 2-4-1 "EGR system faulty (1991 and later California cars)". On several occasions I have gone thru the function tests listed in the Bentley Manual. Everything there checks out ok each time, including the EGR valve function
Well, Chris, thank you for your input and your excellent questions.
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So the PCV nipple is clear. If you disconnect the vac hose from the nipple (still connected to the breather box) and suck on the hose, can you pull air out of the breather box? Do you get a get mouthful of oil?
According to the Haynes manual there is a breather box they refer to as the “later version”. That version of the box had two ports that go down into the crankcase - one to allow oily gasses to hide into the box and another to allow condensed oil to drip back into the crankcase. By doing the “blow into the box” test, and by pouring solvent through the box, you may be confirming one port or the other is clear but no way of knowing if they’re BOTH clear.
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CHRIS MULLET; I appreciate your thoughts. I think you just talked me out of sucking on that hose. I suppose I could do that with a vacuum pump, the small kind used for brakes. What would it mean if that brought up oil? I wonder if there is a method for determining if I have the "later box".
Yesterday, I took the front of the engine apart to find out where exactly the leak is originating. Definitely the crankcase seal, and a bit from the middle shaft seal. Today, I put it partially together - enough to run it. See comment below.
SOME OTHER THINGS I TRIED:
Disconnected the bellows end of the large hose from the flame trap to the intake bellows. With the vacuum hose you mentioned pinched off, I blew on that with the oil cap on. Hard to blow, but I could hear what sounded like blowing in a straw dipped in a thick liquid. I assume that was the air being blown into the oil sump. Then tried again with the oil cap off. Same result, and not any easier to blow into it. With the engine at idle, there was vacuum a the end of that hose. Seems that at idle, fumes are being sucked out of the bellows and go from the flame trap through the little vacuum hose into the intake manifold on the other side of the throttle plate. Meanwhile, at the oil filler hole, there is pressure. Not sure what to make of all this.
With the engine running, I paid attention to the oil dipstick tube. With the dipstick removed I could hear rhythmic noise coming up from there. Don't know how to describe it. Did not notice any pressure building up there - maybe just a tiny bit.
TWO NEW FINDINGS. I tried leaving the dipstick sticking up a couple of inches to see if that might relieve some pressure. That seems to reduce the leakage of oil considerably. With the car in the driveway at idle, I saw only a small amount of leakage. However, when I put it in gear and put a load on it oil leaked quite a bit.
As a separate and new issue, I managed to damage the "key" on the crankshaft gear (aka timing gear). That key is what determines in what position the crank pulley fits to the gear. My question: Given how much torque goes into tightening that crank bolt, is that gear key really necessary? It seems that the tight fit will keep those two pieces firmly together.
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I was not aware that the oil separator box design changed at any point. All the ones I have dealt with had the opening in the top that the hose (3/8" or so) slips onto and the hole in the bottom that seals against the Oring.
I have removed a number of them to clean them. I have never replaced one because I have only heard bad things about the aftermarket replacements. It seems they are prone to coming apart at the seams.
The original ones are very robust. My cleaning method after removing them begins by reaming out the top opening with a 3/8" twist bit. Then I strike all over the outer surface with a small hammer. That breaks a lot of the build up off of the inner surface and allows you to shake it out of the openings.
After I have removed as much as I can with that method I plug the top opening and turn it upside down before filling it with solvent and letting it soak overnight.
Next day I drain it and install a new Oring on the block before bolting the separator back in place.
While I have removed the separator with the intake manifold in place it is SO much easier with it removed.
In your exchange with Chris it sounds like when you attach a hose to the separator and blow into it with the oil cap off you have a restriction or a pressure build up? That exercise should result in no restriction of free movement of air through the engine and out the oil filler opening.
I am not familiar with the set up inside the oil pan (below the separator) but I think something is surely amiss if you get a gurgling sound from the oil pan when blowing on the hose.
Someone who is familiar with that set up would be helpful at this point.
Randy
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Any twenty minute job is just a broken bolt away from a three day ordeal
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When I look at the more reliable parts suppliers’ listings for 1990?-up they definitely show two ports at the bottom of the box. One is the O-ring hole and the other appears to be a nipple rough the same diameter and length as the nipple at the top of the box. That lower nipple fits into a hose that extends way down into the oil sump:
https://www.volvopartswebstore.com/showAssembly.aspx?ukey_assembly=244348&ukey_product=1158601
My theory is that long hose actually extends below the oil level but is still allowing air to be blown through it, making a bubbly noise. The O-ring port, however, is suspect of being clogged. I would have to agree with Randy that there is no reason to not clean and reuse the original box.
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I'm going to go out on a limb and take a shot at what i think is causing your positive crankcase pressure...
I would guess you have the breather box with the two ports running down to the crankcase - the vapor port that allows the excess pressure to flow up into the box and the condensed oil return port that actually extends all the way down into the oil sump. When you blow air into crankcase via the top port of the box the air should follow the path of least resistance into the crankcase, then out through the oil fill port. The breather box port that extends clear down into the oil sump should NOT be the path of least resistance. The port that runs into the air space ABOVE the oil level SHOULD be the path of least resistance. Yet you are hearing "blue-blub-blub" from the oil when you blow into the box upper port. Thus my guess is that the oil vapor port is restricted so that the only way your engine can expel excess crankcase pressure is to push it down through the oil and then back up through the oil return port. That ain't gonna happen.
I believe you need to remove the breather box and either clean it out thoroughly or replace it. ALSO make certain both ports running down into the engine are clear of obstruction.
Fine print: I accept no responsibility for causing you to do needless work.
Good luck!
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To answer issue #10---yes. the grooves are caused by the rubber seal edge. Replacement seals should positioned so the seal is not in the same exact spot as the old one. - Dave
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There isn't a lot of room to adjust the location of the front seal as the seal surface on the front of the crankshaft is very narrow. The rear crankshaft seal has a lot more adjustment as the seal surface on the back of the crankshaft is a lot wider.
If needed, there is a repair sleeve and I try to keep them in stock as the work on the really old Volvos too.
--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com
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Thanks, guys, for your responses. I'm looking for ideas on how to proceed.
james_a_sousa - Yes, if it turns out that the front seal has failed, then pressure and volume is too much for the emission system. The only thing I am aware of that is different on Volvo California cars is the Exhaust Gas Recirculation (EGR) valve. I have tested that item and it works as expected.
The reason I asked about engine speed and load is that I am unclear how the system works under those conditions. Presumably the vacuum from the intake manifold is way down under load. I guess that would mean that there would be even more crankcase volume and therefore more pressure as a result of the increase in volume. I can see that the engine might generate enough pressure to blow out a seal.
This car does not have a turbo. I have read and re-read the 700/900 FAQ material.
I would like to try a simple valve on the oil cap. Do you have a design in mind? I would settle for a cap with a large nipple in it to relieve pressure when driving. Starting yesterday, I've started driving with the dipstick up to help alleviate pressure. We'll see if that makes a difference. I only drive a couple of miles a day since COVID.
Volvo From Heck and planetman - . I tried to dodge the two grooves when installing the crank seal in January, but I realized I could not determine exactly where the seal lip was in relation to the grooves at any given depth.
Got any Ideas for finding a Volvo crank seal installer? There is one on Ebay for $195 plus $30 shipping. Too pricey for this frugal guy. I can't help but believe that most of us install these seals without that special tool.
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As for the issue of crankcase pressure increasing with speed of load - even if pressure did not increase, the volume of blowby would increase.
Perhaps this pressire AND volume is too much for your emission system.
Does your California car have any special emissions equipment on it? Look around for anything that you did not service.
You could try adding a simple PCV valve to your oil fill cap running a hose to your air cleaner as the first ones were plumbed.
Black on sparkplugs is carbon, usually caused by the fuel mixture being too rich. There are spark plug photos on the web.
Have you read the 700/900 FAQ? While your car is not a 700/900, there is a great deal of information in the FAQ that applies to your car, or ANY car for that matter!
Any crankcase pressure must come from your engine's cylinders.
Does your car have a turbo?
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