Trying to figure out what to do with my volvo wagon (~105Kmi). Here are the symptoms:

1. First noticed slight increase in oil consumption over the last oil change period
2. Following oil change (synthetic 20W50), noticed oil smoke from tailpipe after extended idling (~3 minutes).
3. Had breather system checked/cleaned/rebuilt.
4. Crankcase still operating at slight pressure (small sssssss sound when unscrewing the oil cap, oil fogging on AC line near the dipstick). Small amount of smoke coming out of dipstick with engine idling, no increase when revving engine. Does the crankcase run at intake manifold pressure or at turbo compressor pressure (I assume the former)?
5. Oil consumption continued, now dripping out of intercooler drain (I assume, puddle of oil underneath bumper).
6. Compression test: Dry: 150 -155 across the board, Wet: 175-180 across the board.
7. Turbo oil return line clear.

So, my diagnosis is mild piston ring wear and blown turbo oil seals. The question is, are the worn rings causing the turbo seal leak? I tried putting a pressure gauge on the crankcase but it did not register anything, so I don't _think_ the rings are too bad, and can probably put up with the oil leaks caused by the slight overpressure. But, I don't want to mess with rebuilding/replacing the turbo if the engine isn't worth it.

Any experienced advice is welcomed. If I do fix the turbo, any advice on rebuild kits vs. used vs. remanufactured? Any good sources?

Thanks in advance.

 

Tech would be your guy on this but here's a few things to think about if you haven't already considered:

1. Was the oil separator box under the intake manifold changed or just cleaned out? Sometimes a cleaning will not do and you'll need a new one to really reduce crankcase pressure.
2. .7 quarts per 1000 miles is considered within normal for oil consumption.
3. I believe the rings on these cars do have quite a bit of tolerance in them. They are not typical honda or toyota by any means.
4. Oil underneath bumper as you describe is considered pretty normal. Most folks stick a pad in the bumper and swap it out at each oil change.
5. Is this the first oil change with synthetic? If so, perhaps a switch back to dino oil may help 15W40.

 

Yes was the Vent box replaced?

 

All,

The breather box was replaced, along with all of the hoses in the system. This was not the first change with synthetic, I have run synthetic oil since I bought the car at 5oKmi.

The oil drip is pretty excessive (about 1/4 cup in a parking space last weekend after crawling around DC). There is unburned oil accumulating on the back of the car. I am probably at about 1qt/400mi on the highway and there is oil burning off of the outside of the exhaust system - I drive with Recirc on constantly. There is definitely a problem.

I had the front main seal replaced 1.5 years ago with the timing belt and had the breather system cleaned then. This time around I initially through it was the breather system pushing oil in through the valve seals, but the puddles under the intercooler point to turbo seals.

I know compression testers are notoriously poorly calibrated, but the readings seem to be OK (not great, but OK). So it seems like rebuilding/replacing the turbo is the next step, unless you can think of anything else I should try first.

 

My guess would be turbo now as well.

 

So,

In terms of replacing the turbo - is it possible to split the turbo open on the car so I don't have to remove the exhaust fittings? I may need to split it anyway due to model year changes on the used/rebuilt turbo. Also, how difficult is rebuilding one? Seems like it might not be too bad...

 

I think it would be better to remove the entire thing and then swap it out on the bench. Alot easier to work with.

Don't know about the rebuilding I have never done it yet.