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Everyone,
This weekend, which was a hot one in Portland, I was driving the 145 with a relatively stock B20 and ran into some overheating problems. I was running a relatively hot thermostat (192 degrees) but I have had no trouble since doing a reseal on the engine a couple month ago. At that time I put in this brand new thermostat and a new water pump, so I find it hard to believe that those are at fault. Anyway, as I was going up a rather long, steep hill my temperature gauge started going up and when it went past P I slowed down and tried to cool the sucker down. I got over the hill, coasted down and it cooled off but my friend following me flagged me down because coolant hit his windshield and I was puffing white smoke when shifting. We opened the hood to find that the coolant bottle had definitely overflow, pouring coolant everywhere. We topped it off and kept driving, seeing no significant issues beside the puffing white smoke and a temperature needle that seemed to be moving more and more. Once we reached our destination, we pulled out the thermostat for the return trip but this didn't solve my problem. On the return trip, even running without a thermostat at all, the engine would have significant rises in temperature under load (going up hills, etc.) and, if I had not used the heater to help cool the engine, I think it may have overheated once again.
My questions are two fold. First, what are the possible causes of the overheat? I am running a stock, older style radiator with the viscous slip type fan but at high speeds I don't think this is the problem. My friend and I are currently thinking that there is some sort of blockage to blame and are going to try flushing the coolant with a garden hose to try and unblock the system. I was also planning on switching to an early style 140 brass radiator (with the coolant hose coming in at the top center) but I don't think the radiator can be the source of the problem (I have used it previously without issues).
Second, I wanted to ask about the white smoke. This has to mean my head gasket has been damaged, correct? I am planning on replacing it but I want to see what everyone thinks before dropping the money on a new gasket.
Thanks,
Brian
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Overheating without a thermostat means the thermostat is NOT the issue.
In that case it's almost certainly a radiator needing to be rodded out.
The fan can't be the issue; if it were the fan it would only happen in stopped traffic. You can remove the fan entirely and it still won't overheat when you're moving 30+ mph: a headwind is as good as a fan.
Water pump *could* be the issue -- impellers can erode away, but it's not common. Does your heater work? If your heater gets good and hot, then your water pump works.
Timing is very easy to check.
Head gasket may be blown if you've already overheated it badly. Check it but consider it more likely a symptom than a cause.
I would bet good money on a stopped up radiator. Flushing ain't enough -- rod it out.
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Thanks everyone for the quick responses! I did check the thermostat and it was the correct type (it did have a secondary disk on the bottom to contact the pipe in the head). I'll also try and make some time this week to take the new radiator I am putting in to a shop to have it tested before dropping it in. I'll also have my friend drop by with the timing light to see where that is sitting...I thought I had it set it to 15 BTDC but I will check it once more.
Thanks,
Brian
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Everyone,
A bit of an update. I took some time yesterday to check the timing and flush the system. With the timing light I found idle timing at around 800 RPM to be only 5 degrees BTDC. Would this have been retarded enough to cause an overheat? It certainly seems to have been a contributing factor. I adjusted the timing and flushed the system (no major culprits were removed so not sure if this did anything). We then took it for a "spirited" drive and the overheating did not seem to be an issue, but unfortunately it was a cooler day and the hills weren't quite as steep. Hopefully once I get my new radiator back from the shop the overheating should be solved.
As for the smoking, it now seems worse and, having a chance to see it by having my friend drive the car, I think the smoke is more gray/blueish but it is pretty hard to tell. I get little puffs when shifting or when starting from idle. I can get really big amounts of smoke by coasting down a hill in gear (about 3k RPM) and then hitting the gas. My friend and I are planning on pulling the head this weekend and replacing the head gasket and valve stem seals while its out. Hopefully nothing is too warped or I have damaged something in the bottom end!
Thanks for all the help!
Brian
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That smoke is oil, no doubt about it. The only doubt is, where is the oil coming from?
You can try a 'wet' compression test (squirt a bit of oil into the cylinder and test again - if it goes up, that suggests rings. The oil seals the rings to the walls, so if they aren't already sealing they certainly will when oiled.) Your compression numbers are not bad. And like others have said, the valve guides are the likely culprit for this kind of smoke.
This type of smoking is not uncommon and an engine can run a very long time with oil seeping past the rings or valve guides, so if you can't fix it now, fix it later.
If you've ascertained that oil and water are mixing, and all you can do is the head gasket and the valve guide seals, do that. BUT: Know going in that there is an outside chance that the head has been cracked by overheating. It does happen. And it would explain a sudden onset of all these symptoms. Get a magnaflux kit and read the instructions, or have the head checked by someone who knows what they're doing. If downtime is an issue, you might want to have a plan for what to do if the head turns out to be cracked. If you have a friend who's got Volvo heads lying around his garage randomly, now is a good time to go have a beer with him. In fact, take him bowling. Not that I think your head's cracked, but it's a good idea to brace yourself for that possibility rather than be blindsided by it.
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Ok, another update :) I drove over to a friends house yesterday and fired up the trusty compression checker. All cylinders were 145 except for #3 which was 140 (after taking perhaps one or two more cycles to get there). Also interesting was the fact that there was a drop of oil on the spark plug in #3 when I pulled it out...certainly it seems that #3 is the source of the oil burning issue and the drop seems to indicate some sort of valve issue (seal or possibly worse)!
Also, after driving it around yesterday we popped the radiator once again and the water we put in is definitely turning a milky color and smudges of oil appear on paper stuck into the coolant...I think a definite sign of some sort coolant/oil mixing happening from the head gasket. Thankfully I am not seeing any coolant in the oil yet but this weekend I think I will definitely tear off the head and put on new head gasket and valve stem seals, of which I already have a set that I forgot to put on when reassembling the head the last time around.
Brian
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I've been following your thread and everyone who posted had valid ideas. Now you've added a bit more information to the mix. My own thoughts originally leaned towards a radiator in need of rodding or replacement.
You may very well have a blown head gasket but the smoke you describe is typical of worn rings and/or valve guides and/or stem seals. I don't think I've seen you mention a compression test anywhere. Before yanking the head off I'd at least do that--it should show up a blown gasket--or worn rings and the plugs may show evidence of one or the other. A blown head gasket (or cracked head--as I found on a Saab) will sometimes cause a cloud of white smoke (vaporized coolant) on cold start-up-- a symptom to look for.
My point is -- if you take the head off are you prepared for the down time if the valve guides are bad?---or the rings? What is the point of changing the head gasket if it is not actually the problem---better to save that gasket for use in a motor rebuild--which you will be looking at some time in the not too distant future if the smoke is oil.
I'd install the replacement radiator, set the timing properly (does the advance work?) and see what you've got now. --- (lazy)Dave
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Dave,
I agree that I am not 100% sure about the head gasket being the issue but the sudden onset of this smoking so quickly after the overheat has been worried about the reliability of the engine...hence the I guess eagerness to dig in and see what is up. A full rebuild is not in the cards right now, however, so perhaps just leaving it is best. I will definitely do a compression test soon and report the results. This will hopefully give me some more info.
Thanks,
Brian
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The second description of the smoking definitely made me think of valve seals.
--
'63 PV544 rat rod, '93 Classic #1141 245 (now w/16V turbo)
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I think there is a good possibility you've blown a head gasket... which may have been the source of the overheating problem in the first place.
This will usually show up as bubbles in the radiator (or expansion bottle if so equipped). Fill the cooling system, start it and let it warm up, then check for bubbles in the water. There may also be a gassy (exhaust-like) smell at the radiator cap opening or at the open expansion bottle with the engine running.
--
Gary L - 142E ITB race car, 73 1800ES
BlueBrick Racing Website
YouTube Racing Videos
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Yep. puffing white smoke out the tailpipe is a pretty good indication of a blown HG. Does the exhaust smell a little sweet? (Side note: I've been running E85 in the 245 for a couple of years now - on a cold start it will put a rather sweet smell from the exhaust pipe - that made me repeatedly worry about a leaking HG).
There are some test kits that will test the air in the cooling system for the presence of carbon monoxide - which would only get there from combustion getting pushed into the cooling system past the HG. They can be a good diagnostic tool on a borderline case.
But this isn't really sounding like a borderline case, it's sounding fairly obvious. The overheating is a side effect of the hot gasses being injected into the water jacket and overpressuring (and over-heating) the coolant.
Pull the head, check it for flatness, check the block too for good measure (has anyone ever found a warped block? ). Put it back together with a new HG and use proper patterns and torque values on the head bolts.
--
'63 PV544 rat rod, '93 Classic #1141 245 (now w/16V turbo)
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Be SURE and check your ignition timing. Retarded ignition will do this, especially on
a heavy load. Will also overheat the exhaust system, burn up the exhaust downpipe and
crack the exhaust manifold.
BTW as best I know they don't have hot weekends in Portland.....
Where they have hot weekends is Yuma, Death Valley and, occasionally, here in Oklahoma.
--
George Downs Bartlesville, Oklahoma
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First check that you have the correct thermostat as indicated by planetman.
But don't rule out the radiator. When's the last time it was rodded out? Flushing won't do it for a 40 year old radiator. It really needs to be scraped clean. It's amazing how much crud will build up in there over the years.
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No idea how this works on a B20, but when my '79 240 had similar issues it did end up being the radiator. The key to me is the fact that when it starts hitting its peaks, it could easily be brought down by turning on the heater.
The slowly rising temp gauge started during a bonsai run from Tulsa, OK to Madison, WI and back in 36 hours. This was a B21F with a BW55 and we cruised at 70+MPH most of the time. Any time the grade would steepened even a bit the temp would climb to about 3/4. Turning on the heater, no fan required with the flow-through the older cars had, would pull it back down in a short 10 minutes. The Husky did not like it much since it was only about 50F outside the rest of us did not mind.
When we got back, I replaced the thermostat and water pump. No change on the next highway trip. While the radiator was out for the water pump install I took it to a radiator shop (old Blackstone? brass radiator) and they tanked it and pressure tested it but said it likely needed a re-core. So when things did not get better, I installed my spare aluminum and plastic radiator...problem solved!
Mike
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Hello,
Are you sure you used the correct style of thermostat?
The correct thermostat has a secondary disc mounted on the end of the central shaft.
When hot, this disc lowers to cover the little pipe below the thermostat.
Without the secondary disc, water will not flow properly through the head when the thermostat opens.
--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
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