I bought a Volvo 850 T-5 (which runs also on lpg) yesterday with a 3" downpipe and a MTE (ET) upgrade (about 285 hp and 420 nm) and it has the next problem.

At idle when i press the pedal a little bit and then lift, blue smoke comes out of the exhaust. It also smells like burnt oil.

When i accelerate with little or full throttle no smoke is seen. But when I accelerate fast and then changing gears or lift the pedal a blue cloud will appear.

Sometimes...not always..it also seems theres coming a little bit of smoke from the dipstick hole. I can also see some (old) oil drips on the inlet. Seems there's too much pressure.

During full throttle it seems that te car is hestitating a little bit its not one fluent power band i believe. Sometimes the turbo indicator goes to it max but sometimes i think it doesnt.

When changing gears at very low throttle i also noticed that the rpm raise with about 500 rpm and then slowly return to idle (when pressing the clutch). When i accellerate fast the rpm wouldt raise during clutch/changing gears.

I sometimes hear the turbo 'singing' a little bit.

The previous owner did a rebuild on the head and replaced the turbo for a rebuild one. He placed the turbo hisself and even then the blue smoke didnt disappear. Could it be that he mounted it wrong? Or sometimes with the lines?

He got crazy from the oil usage of 1 litre for every 1500 km and the blue smoke and some little details more and therefore sold the car.

Any ideas before that im going to change the turbo again? I cant imagine the piston rings are bad, cause the engine itsefs runs very smooth and during accelleration theres no smoke at all. Normally when piston rings would be bad there would be smoke during accelleration.

Thanks for the replies.

Janno (from Holland

 

Did the previous owner replace the PCV system? Bad valve seals usually cause blue smoke at start up. Bad rings would probably cause smoking under light and heavy throttle. I think the engine is probably fine, its probably just a clogged PCV system causing too much pressure in the engine.

I don't know if it would be causing any of the other problems.

 

The valve seals were replaed at the same time the head got a rebuild.

I did send the previous owner a message about the pcv system.

Could it also be an oil return line? Or vaccuum line from the turbo? He did the turbo change himself so that would also be possible.

Thanks

 

My guess is something clogged in the vent system(PCV)

 

Sorry to be the bearer of bad news but that kind of oil consumption is a classic symptom of worn out rings. I assume you have changed the oil at least once since owning it? If not, try that first; gas in the oil can precipitate excess oil consumption too.

You already got a high output engine (stock was 222 hp) and the upgrades are pulling even more hp out of it; i.e. that's one stressed engine there. You didn't say how many mls/km are on the clock, but i imagine it's a few.

You can replace/repair the PCV system but I seriously doubt it will help. Sounds like you have a nice car that's ready for an overhaul.

 

The car now has done about 295.000km, pretty much bit this kind of enigines can do more easily...on the dutch volvo850forum there many with even more power and drove 400.000 without replacing the rings.

I thought that piston rings would show smoke under load, not at idle? But as i read here it can also show smoke at idle?

I know somewhere there has to be a write up for checking the pcv system, but i cannot find it. Someone has a link for me?

Thanks.

 

If you fear rings do a compression test. But I doubt it.

The best way to check the PCV system without pulling it apart is to pull the dipstick with it running and see if it smokes like a train.

 

I agree with tech; do a compression test; heck, do a leak down test too while you're at it; more info is always good. But ultimately that may, or may not, tell you if oil is going past the rings. From your symptoms it sure seems like it is.

A story:
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Back (long ago...) when i was in my early 20s, i bought a used car from a dealer. It had less than 100K mls (62.100 km) on it, ran fine, compression good on all cylinders. But after owning it for a couple of weeks i noticed it used a quart (slightly less than a litre) of oil every 300 mls (500 km) or so.

Since i had a 60 day warranty, i took it back to the dealer. They looked at it and insisted it was valve guide seals, so they overhauled the cyl head only. Got the car back, but same thing; excessive oil consumption. I finally got them to rebuild the bottom end too, which solved the oil consumption issue.

BTW: i never saw (or i should say noticed) excess white smoke out the tail pipe when it was using a quart every few hundred miles.
================================================== ======


The point is, from my experience, when you have that kind of oil consumption, it's generally the rings.

You say you know of volvos that have gone 400.000 km w/o rings being replaced; yes that's true; if they are properly maintained with regular oil changes throughout the life of the vehicle, and if it was never abused too badly, etc, etc.

So for sure, do more diagnostic work and ck out the PCV system and replace/repair as necessary. But ultimately i think you're looking at a bottom end overhaul. Hey, I hope I'm wrong; keep us posted with what you find.

Here's the link that i know of for PCV replacement; see tech's post for diagnostic; pull the dipstick and see if it smokes out the pipe.

Good luck!

 

Tackle the PCV system first. Its better to start off with the basics rather than condemning your motor. Volvo has a common problem with pcv issues. Replace the oil separator box and clean all the vapor lines, any clog will cause blue smoke. You can always pull the turbo inlet pipe and check the shaft endplay, excessive endplay means a worn turbo.

 

Hmm the smoking @ idle is even worse...now the cars smoke on idle without touching the throttle. When i pull up there seems to be little or no smoke. It really smokes like a train now.

Strange thing is that yesterday when i tested if it even reached it topspeed the smoke after that was much less. I was able to get it at 260 km/h on tacho and there sure was more, but i didnt want to harm/stress the engine even more. Besides that i thought it was little to busy on the german highway so i decided that it was enough.

Next week the garage is going to do a compression test with cold and warm engine. Hopefully then i know more...and hopefully not...because when not the turbo is nr.1 suspicious.

The previous owner had cleaned the pcv already and replaced the pct valve for a new one.

Are there any oil (return) lines from the turbo i can check if they are clogged?

Thanks again.

There's no smoke coming from the dipstick

 

Just an addon:

I think my turbo is more and more suspicious. I did some test runs today and monitoring the turbo pressure gauge.

The turbopressure should be from anywhere around 3000-3500rpm at the most right (for a chiptuned 850). I noticed that sometimes the pressure gauge goes all the right but it doesnt do it always. Besides that i noticed that above 5000 rpm the gauge is only at 3/4 of its max, so the turbo is already loosing power from 5000, looks more like a lpt. Almost only in 4th or 5th gear i'm reaching the max sometimes.

Besides that i noticed that un full throttle the car hestitates for a quarter second or so and then pulls further on. Sometimes it won't do this and sometimes it does it twice.

What you guys think when you read this part?

EDIT: I did see some oil (not much) in the hose from the intercooler to the inlet..is this bad of normal?

 

Unfortunately I really don't know how to determine if turbo is using oil. Do what volvotechpaul said in previous post and ck for end play.

Have your guys at the garage thoroughly ck the turbo when you have it in there; maybe they can determine if it is using oil. Maybe that's it.

Good luck and keep us posted!

 

I checked the spark plugs yesterday for uncomplete burning or oil burning, but they look pretty good.

Despite theres no crankcase pressure at idle i did see that theres oil on the hood, right above the dipstick. So it seems that on throttle there is (too much) pressure after all. This makes the rings more suspicious again. Seems like i have to go for a rebuild after all, but i'll wait for next week what the compression test tells me.

 

Don't be too hasty about a rebuild. Have a tech look at your turbo. That is usually the cause for a smoking turbo Volvo.

 

Update:

Got my car back from the garage. Compression is fine, turbo seems fine too, there wasnt much oil around the hoses from the turbo and when the turbo would leak oil that hard there should be oil in it.

Only thing what is left my garage think is the rings after all. This may declare the reason why the RMS is leaking a very little bit again and that the RPM goes up by 500 RPM sometimes when changing gears.

As far as i'm concerned now the engine block needs a rebuild .

There goes my holiday cash...

 

Well if the compression is fine then the rings are good. If the rings were bad you would have low compression.

 

Sorry i have to correct myself, the garage told me the oil control rings, not the piston rings were bad. When the oil control rings are bad you cannot (always) measure this with a compression test.

I have one little question, but i think thats another problem...my turbo sometimes looses its pressure (not completely but just a little) and just for half a second or so...after that the pressure is directly back at its max. Is this a vaccuum problem?

 

You could have a leak somewhere.

On the rings you can do what you want but I have not seen a set go bad in my almost 15 years working on these cars.

 

I agree with TECH. I don't think that rings are your problem. Are you witnessing any blow by?? Excessive crankcase pressure under boost is also a sign of bad rings. Run a compression test, good numbers are from 120-150 pounds. Then add a squirt of oil to each cylinder check again. Did you see a big difference in compression or not? Bad numbers are any where below a 100 pounds. A big difference in your numbers means bad rings if not, check your turbo again......very suspicious.

 

I have some little oil drips on the inside of the hood and around the dipstick...at idle at least theres no pressure but it seems under load there is.

When i pull her to redline and then change gears its a really big blue cloud coming out.

The compression was superb. I don't now how to convert it to pounds but it was about 12,5 bar on each cylinder. I think that is abt 185 psi or something. There was very little difference between each cylinder.

My garage is sure its the oil control rings but i'm going to have a second opinion this week. They told me compression doesn't say anything about the oil rings, but it tells something about the cylinders, pistons and the piston rings.

I noticed again and again that the turbo gauge sometimes is completely right and sometimes not all right at all. When i accelerate smoothly and then go to full throttle the gauge will go completely right. Above 5000+ the gauge goes back to the left a little bit.

Keep you updated....