Hello,
This is my first time posting on here although I've been lurking for awhile now. I have a '94 850 Turbo that I just purchased in Feb. and I love it BUT it's having some serious problems and I don't know where to start.
A couple of months ago the odometer stopped working, then on the first warm day we had here, it suddenly started hesitating a little when it got around 55 MPH and above. Once the speed dropped it wouldn't do it anymore but the turbo guage would stay in the middle, even when idleing. The next day I took it for a short drive and it started doing it at slower speeds and would occasionally idle a little rough. I had given it a complete tune up 2 months before this when I bought it but noticed that there was white smoke coming from the dipstick. I checked the PTC nipple and all the hoses were fine so I replaced the PCV system.

When I got done I started the car and it ran perfectly. I left it running while checking for leaks under the hood and under the car and found nothing leaking. Turned the car off, put tools away and started it to take it for a test drive. It started right up again and was still running perfect. Got out of the driveway, up to 35 MPH and it wouldn't go any faster and I couldn't push the gas pedal down anymore. It also started hesitating pretty bad and there were little puffs of white smoke coming from the tail pipe. When I stopped to turn around it acted like it was going to die but didn't and did the same thing going back home. Went out that afternoon to take another look at it, started it up and it ran really, really rough for about 15 seconds and died and wouldn't start up again. Looked under the hood to see what I could see and tried to start again, started and ran rough for 5 seconds and died. Now there was small puffs of black smoke from the tail pipe. I re-checked everything to make sure I didn't forget to connect something and all hoses and sensors are connected. The CEL is on and I have no idea where to even start looking for the problem. Oh, and the odometer still doesn't work (the least of my problems right now) and the turbo guage still sits in the middle.

Any help is really appreciated!
Thanks,
Katie

Well typically the odometer is an easy fix but a little time consuming. Generally is is due to a small plastic gear that breaks a tooth. They tend to break around 100k or 200k miles. The gear can be bought in many places on the internet for a couple of dollars, but replacing it requires removing the instrument panel from the dash which is a little time consuming, but nothing difficult.

The major issues, I am not positive of.

Out of curiosity, check your oil, especially if you are seeing smoke out of the dipstick tube. Is there a milky film on the oil (after it runs for a minute), or posibly a light smell of anti-freeze? Either could suggest a serious issue of your coolant getting into your oil, which can cause some serious damage. Had this happen in a Toyota awhile back (except mine dumped all the coolant into the oil at once), which put an end to the engine for awhile until I tore it apart and rebuilt it. It had similar symptoms, but over a much shorter period of time due to it mixing so much coolant in the oil at once, but during that time the engine started running real rough and would die if I let it idle, and I lost over 75% of my power. After a few restarts trying to get it somewhere to work on it (eventually I had to leave it on the side of the road), it would no longer start up at all.

I would suggest not driving it any more than i absolutley necessary until you get it figured out, to possibly save any potential damage. Even having it towed to a mechanic rather than driving it.

Others here may have much better insight into this, and my suggestions may be wrong, but due to how your car is acting right now, I would err on the side of caution as major work on a Volvo can get expensive.

actually, i agree with you except for the driving it part. don't. also look under your oil filler cap, you know the big round disc on the engine. look under the cap and see if it looks milkshakish. and the odometer is just a gear that is messed up, but like you said, least of your problems at the moment.

Start with the Stage 0 parts, and move from there.

Bear is right, and so are greek and balckbyrd.

Do also clean your IACV and your throttle body, as well as check for hoses that needs replacing. Could be your vacuum hoses are torn or worn out.

White smoke out of exhaust pipe = worn injector seals? Not so sure, but its on of them seals that needs replacing.

Good luck, dude.