1997 850 turbo bad or valve seals?

1volvoguy · Post by **1volvoguy** » 24 Sep 2014, 08:27

Hey all,
new to the site! Thanks for letting me be a part of it. So I am here due to some issues I am having. I will give you some history and it will lead to why I'm here.

I bought this 97 850 turbo sedan from a college kid, engine died and dealer quote scared him. I got the car at a good price. The issue, diagnosed by dealer as a head gasket. My son had a volvo 850 non-turbo, great car so I figured I'd take a shot at it. Got it home, tore it down, and sure enough, the head gasket was toast. So I was told, the car didn't overheat, just started losing coolant, then started skipping and it got towed. I will never really know, but that's what I was told by the kid selling the car to me. And we all know how honest some car salesmen are right? lol His friend made a comment about it using oil. When I pulled the car apart the turbo tubing had some oil residue. Turbo? maybe? I cleaned it all up, replaced head gasket, timing belt, water pump, spark plugs, did oil change twice in zero miles, let it get to temp, changed it, drove it 15 minutes, changed it again, so oil is clean now. But I left the turbo. I wasn't clear if it was bad or not so I figured it would present itself once the engine ran right. So after some time running, smoking to clear out coolant and whatever out of the exhaust, I can't get it to stop smoking. Now it holds coolant fine, But the smoke (blueish) won't stop. I still suspect the turbo. But heres the part that you will shake you head at. I pulled a boneheaded move, and it could be my issue. When I did the head gasket, I didn't replace the valve stem seals. The car only smokes at idle or when coasting. And when idling it smokes like a chimney. So is vacuum drawing oil from stem seals or turbo? I did check compression. I have 180 psi dry test with engine cold. I read somewhere its recommended to test is warm but I did see 180 hot was good. I would expect it to rise is I checked it hot. 180 seems pretty good for cold(70 F). All 5 cylinders are almost exact. So I'm thinking rings are fine. Runs good, smooth, solid, just the question, do I replace the turbo, or is it more likely the engine is still having issues due to the stem seals? For me it comes to this, I'm not into it too far right now. I don't want to throw a turbo at it for nothing. I think with the oil residue in the air tubing it leads me to the turbo, but I guess what I want to understand, does it sound possible that the turbo would leak at idle? And not while you are mossing on it? Under boost the smoke clears. Stop at a stop sign and start coughing. lol
I haven't run the car more than an hour or 2, only driven it probably 10 miles. I may still have some exhaust burn off to do, but this smoke seems to have a source. The smoke it blueish but really doesn't smell much like oil? The smell may be due to the cat?
Any help or suggestions on how to better test the turbo would be appreciated.

1volvoguy · Post by **1volvoguy** » 24 Sep 2014, 10:56

Sorry, I think it is a 1996 if that makes much difference. Also, I did replace the pcv box under the intake, and the tubes are clear.
Started the car today, the exhaust smells a bit like un-burned gas? With blueish smoke.

Post by **j-dawg** » 24 Sep 2014, 11:15

if the turbo is shot, you should see smoke under hard acceleration as oil is burned in the exhaust. under hard acceleration with busted valve stem seals, you should see no smoke after whatever had been drawn in earlier is burned away. idling or coasting - and especially giving it some throttle after idling or coasting - should give you a nice blue cloud.

have you checked the turbo for shaft play?

Post by **timmybdaddyof3** » 24 Sep 2014, 11:17

what kind of mileage are we looking at overall?
Based just on what you've said I am kind of leaning towards valve stem seals as normally a turbo you will see more smoke under load than at idle - but then again there's nothing normal about normal. I small amount of oil will generally be present in the air intake lines of a turbo car.
Lets see what kind of responses you get, and then PM me and I will tell you how we quick diagnose it at the shop...not that its a big secret, but I don't want to publicly print something that done wrong could damage a motor

1volvoguy · Post by **1volvoguy** » 24 Sep 2014, 12:32

the car has 156,000 miles. I didn't check shaft play on the turbo. Its easy enough to do though so in the next day or two I will pop off the exhaust and check it out.
So if it is stem seals, I am safe to assume the head has to come off again? Really not interested in doing that. If it comes to it, I will kick myself in the butt for not doing it while I had it apart. Lesson learned. Again! No short cuts!

Post by **jblackburn** » 24 Sep 2014, 14:04

You said you replaced the PCV box - were the ports/lines severely clogged beforehand? A clogged PCV system (or tons of oil in the intercooler, etc) will make lots of blue smoke at idle.

If it was really clogged up and there's a lot of oil in the turbo hoses, take a hose and some Cascade dishwasher detergent, pull both air lines off the intercooler, and give it a good rinsing out.

Post by **j-dawg** » 24 Sep 2014, 14:37

it's possible to replace the valve stem seals without removing the bottom half of the head, but the cams have to come out and it's not easy to get the seals out.

you don't need to drop the exhaust to check for shaft play. you can access the shaft from the intake side, which is probably easier.

Post by **rspi** » 24 Sep 2014, 19:41

Will seafoam clean out the turbo and intercooler & tubing if you let it get sucked into the intake post the MAF?

Post by **jblackburn** » 24 Sep 2014, 21:40

I wouldn't try running it through the turbo, and I doubt it would do anything in an air pipe anyway.

Post by **timmybdaddyof3** » 24 Sep 2014, 23:20

Seafoam won't clean it, Volvoguy, check your PM and give me a shout