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Q: Just how much does clogged-up PCV influence idle and running condition? I know excess crankcase pressure can blow the main seals, but barring that just how much does the PCV influence running condition?
Background:
With the slightly warmer weather, I finally started opening up the intake side of the engine in my 20-valve 1994 850 Sedan.
I got into this part of the engine to replace the knock sensors after a 1-4-3 code and a CEL. The engine runs nicely, but there are a variety of noises to be traced and sorted out - particularly at low idle.
What I found down there should come as no shock to anyone who has bought a Volvo from a non-Volvo person.
Utter filth on everything - old oil, dirt, grunge, crumbing wiring tubes, etc. Not a huge shock, but never a particularly welcome sight. The PCV Flame trap was ~90% clogged. There was caked up crud in the TB intake. The bottom of the oil box was 50% blocked by crud. The PVC hose itself had a kinked rigid piece of tubing silicon-ed inside the elbow on top of the oil box - sort of a half-assed MacGyver...
I also found x3 manifold bolts, x2 large flat injector seals, the screw for the throttle-spool cover, and some other stuff practically pasted to the block by the crud.
Reportedly, this engine was rebuilt back in 2009, seems they dropped half the hardware in the process.
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posted by
someone claiming to be fixit 2002
on
Wed Feb 20 09:07 CST 2013 [ RELATED]
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One thing you also may want to do soon is grease the front door stop devices. The attachment points to the frame are very weak and the thin metal will fatigue and break when they get dried up and the resistance increases.
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I hear ya. My c70 has a busted front door strap - no fun at all on hills and slopes.
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posted by
someone claiming to be fixit 2002
on
Mon Feb 18 12:10 CST 2013 [ RELATED]
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The flame trap has a small hose connected to it and that connection point will probably be plugged. It needs to be drill out to clear. The vacuum tree also has a hard plastic hose connection that also is probably blocked. It will need to be replaced.
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Good advice. I've never seen a flame trap that looked like this before...
The clean spot in the insert is from where I used a screw to extract the insert.
(I've installed an entirely new assembly sans insert)
I've removed all of the PCV parts and intake plastic for cleaning/replacement. Shockingly.. the tree is the only "clean" thing on the intake - probably because the small hose from the flame trap to the tree was unhooked.
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You just might want to invest in an AutoRx treatment. That is really gross! The AutoRx requires regular oil, not synthetic, and at least 1,000 miles of driving to clean the engine internals. You know it is working when you look at the cam under the filler cap and the brown/copper color is gone.
I am not looking forward to warmer weather, only because of what I will find in my junker.
I am currently doing a SAS delete. I think after unplugging the air pump and blocking the vacuum line I found out why I keep getting P0410. The solenoid has 0ohms resistance. Too bad the Pick&pull is so far away, there might be a good one there. Of course, soldering in a resistor before the solenoid might just work.
I haven't taken any pics of my ride, it is too embarassing to look at! The leather is all gone on all 3 seats, the left rear door is dented, the headlight wipers need to be replaced, the trunk lid looks like a T-rex chewed on it, etc.
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My name is Klaus and I am a V♂lv♂holic
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AutoRX.. haven't heard of it, but some sort of deep engine cleaning is probably a very good idea. I usually go with the OEM filter, fully-synthetic Mobil1, and magnetic drain plugs to get the system clean.
This might be a very good candidate for a checmical additive. It's just had afresh dino-oil change, so this may be a good time.
Also, forgot to mention. I found the emulsified oil in the bottom of the oil trap. I'm thinking it a result of condensation. The car wasn't getting much exercise when I bought it. the owner was ~5 miles from his job, I'd guess that it rarely reached peak operating temp.
On the up-side. aside from the rusty edges on the hood, and bumper dent, the body and interior are in excellent condition. The list of problems is very short.
Small tear in the driver's seat bottom,
Missing door card on the passenger front door,
One busted off lock knob in the back,
Broken antenna mast,
Fallen headliner/sunroof,
Peeling paint on rain gutters.
If I can get the engine cleaned up and running nicely, it should be pretty sharp.
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Yeh, the bottom of the block makes for a handy storage place for dropped parts. Keep'em, you never know when they come in handy.
A clogged PVC system can create 'breathability' problems which can mess up idle speed and top end speed, along with blowing seals. Your engine runs on vacuum parameters, and the change in vacuum will make the computer think the engine is either running faster or slower than it really is.
Knock sensors do die, but many mechanics install new ones with the wrong orientation and that overloads the computer with false readings. So be careful when you put the new ones back in.
The crumbling wire harness covers can be corrected with large vacuum lines slit lengthwise and a few wraps of electrical tape.
Next month is my turn to open the bonnet and take a looksee, I do need to wait for the ice to melt on the garage floor.
Currently engaged in the SAS bypass.
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My name is Klaus and I am a V♂lv♂holic
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This post has been marked as an answer to the original question.
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I can't be too critical there - I've lost plenty of things down there. It does neatly explain why I had so many 11m-head bolts on the manifold. It made the job a little extra-obnoxious...
Here's the situation...
It could be a lot worse.
Here's a shot of the car
I also have plenty of that flexi-tubing from the C70 project in 2011, so I'll just re-wrap the wiring. I like having things clean and tidy down there.
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Is this photo taken just after the manifold is off? Or, was there a lot more stripped off the block?
I was hoping to do the throttle body and told to get at the PCV was to detach the manifold.
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This shot is with the manifold, oil trap and starter removed. Removing the starter was unnecessary, but I wanted to get in behind it for cleaning and to hunt up missing stuff.
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Repairman, do you have to replace manifold with a new gasket?
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