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almost bought a Volvo today, need diagnosis help

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PATR8

PATR8

Jedi Knight
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I, as every one here has been reading, have been looking for a Vovlo for my son. It seemed almost hopeless then yesterday I saw a young man walk out and put a for sale sign on a sweet white 940. On the way home I stopped and took a look at it. The interior was worn but the exterior was mint, not a spot of rust on it. The lady who's house it was parked at said it was her nephews and he woudl drop the keys off so I could look at it the next day. So today my son (just back from Georgia) and I went up, the car started right up, we drove it about 10 miles , a/c worked great, every thing worked!. We were excited, even considering paying the asking price. We stopped at a stop sign, 400 meters from the guys home, pulled out and we layed a smoke screen thick enough that the cars coming down the road behind us had to slow down.

Of course the owner did not know of this and upon closer looking at the car I noticed a new bead of silicone around the thermostat housing. It seems the smoke occurs as when the car shifts gears and the RPM drop suddenly. Any ideas what could cause this? the seller's uncle (a GM mechanic) suggested a PCV valve possibly). I doubt it was rings as it seems it would smoke all the time if that was it.. I hope some one here has an idea that it may be some thing simple
 
Re: almost bought a Volvo today, need diagnosis he

Could this "smoke" be brake fluid? Brake booster failure. Rapidly pump the pedal at idle and note engine RPM. If it drops/stalls the booster is suspect. Then rev the engine (in neutral, please) and see if the "cloud" appears again.

Oil burning is a blue-white color, water/coolant is white-white and smells sticky-sweet, it dissipates rapidly as well... brake fluid is white and stays around like tire smoke, smells awful too. Gotta know which commodity is bein' burned before more guessing.

"Why is that Major sniffing those exhaust fumes?" :jester:
 
Re: almost bought a Volvo today, need diagnosis he

The other thing it could be is a blown up turbo. You didn't mention it being a turbo model, but the description of the thick white smoke sounds like what my wife's turbo Beetle did to us - twice. Thankfully we were warranteed.
 
Re: almost bought a Volvo today, need diagnosis he

Which engine, make a big difference!

There is no PCV valve on this car. Volvo uses a flame trap and oil seperator system. The oil seperator lives under the intake manifold. It can get blocked on the drain side, especially if it's been removed and reinstalled incorrectly (easy goof). This can make the engine smoke when this oil is sucked into the intake. If it gets plugged on the vacuum line (common) it makes the oil leak out of the engine due to crankcase pressure.

Turbo models can smoke as the turbo wears. With wear the turbo leaks oil into the intake. Though this shouldn't result in splotches of heavy smoke, it more typically causes general smoking.

The 16 valve engine does have wear problems and is capable of smoking due to worn internal components.

ATF does not come into play as there is no vacuum module connection. The transmission is controlled by the cable connected to the throttle linkage.

Brake fluid is faintly possible, but highly unlikely. Easy to check, just pop the vacuum hose and see if it's dry.

Coolant is possible, but only faintly on the 8 valve models.
 
Re: almost bought a Volvo today, need diagnosis he

A dirty forgotten air filter can make a turbo smoke too. High inlet vacuum can pull oil out of the turbo bearings and lay a smoke screen. If this is the case, it says nothing good about the maintainence that the car has gotten lately.
 
Re: almost bought a Volvo today, need diagnosis he

It is a non-turbo. We are going to go back tomorrow to look. If I understand it correctly, if I pull the hose from the flame trap to the air intake off, it should stop smoking if the flame trap is the issue?

The guy today says he thinks it may be losing some water too. The body is so sweet it is a shame to lose it if it is a simple problem.


Oh, I forgot to classify the smoke, I did not get a good wiff but I would beleive what I smelled was oil smoke with a 75% reliabiliy.

We sat and talked today, the only things we noticed it definately needed was a door seal on the driver side. It is completely missing
 
Re: almost bought a Volvo today, need diagnosis he

The White Smoking Volvo we were looking at was sold after we passed on the deal. It so happens a lady I work with told her husband we were looking at it and he rushed down and bought it for the asking price. 3 days laters the engine gave up one of it's ghost. The head gasket went and who knows what else. I would feel bad but the seller was honest about it and the buyer thought he was stealing it out from under us. Well , he has a very nice body to start his repairs with
 
Re: almost bought a Volvo today, need diagnosis he

Sometimes, things work out for the best, don't they? :laugh:

I'm laughing about the guy who thought he'd pulled one over on you.....
 
Re: almost bought a Volvo today, need diagnosis he

Me too. Even better, it didn't take months. :smirk:
 
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