94 850 smoking, revving, hissing

[Matiss]

I have a 1994 850 turbo and have been running into some problems lately. Some background- I've had the car for 18 months and have done some basic mainentance- did a full tuneup, changed the timing belt, serpentine belt (with help) and fuel pump (along with oil changes).

After a recent ~250 mile round trip, which is nearly all uphill on the way back (Phoenix to Flagstaff) I pulled off of the highway, idled at a few long lights for a total of ~5 minutes, and pulled into a parking lot. Upon acceleration from the last stoplight, a massive cloud of grey smoke came from the back (I'm not sure if it came from the tailpipe or was funneled under the car), and as I slowed down into the lot, smoke was coming from under the hood.
The car thermostat (~a year old) showed normal temperature, the car did not overheat. I turned it off, opened the hood and saw smoke coming from the back of the engine block on the upper most seam, about an inch down and directly behind the engine block bolts.

I looked inside the car quickly, there was a bit of smoke coming out from the middle air vents.

Under the car, oil was dripping from a few spots- none were on the oil pan, but toward the driver side of the car. I changed the oil less than 300 miles ago, and noticed that the oil dripping was dirty/black, but oil on the dipstick is still nice and clean. The dipstick does not smoke, but there is oil accumulation on top of the engine block.

Also noticed that on the drive back, which is uphill and puts he car under load nearly the entire time, there was oil film accumulating on the rear window (it's a wagon). After the smoking episode I detached the air hose that runs from the turbo over the engine to the air box and found a decent amount of oil at the connection to the turbo (behind the engine).

A few other points- when it has been driven "hard" or has fully heated up and then is turned off, it does not restart immediately. (For example driving on the highway, if I stop at a rest stop for 5 minutes and come back out, it doesn't restart right away. It usually takes about ten minutes to be able to restart it.
However, if it has been driven around town and is idling a lot , it is prone to stalling and not starting immediately. It has recently also revved while idling- it goes up from the standard 900-1k rpm to 2k and even up to 4K on a few instances.

The car runs very rough, and just got the codes read.
It came up as:
Bank 1 system 2 rich
Cylinder 2 misfire
Cylinder 5 misfire
Random misfire
P1310

Last note- about 2-3 weeks ago I noticed a hissing sound coming from the engine compartment. At first I thought it sounded like rubbing, but have realized it sounds like air hissing- seems like it would be a vacuum leak of some sort. I can't quite tell where it is coming from, but seems to be on the driver side.

Sorry for the long post- any help or insight is welcome and appreciated!

[kahl]

I think you have several things going on...
1. Do a glove test thereby checking if you have positive crank case pressure. Tie wrap a rubber glove over the oil fill cap and if it inflates you will need to do your PCV system. I suspect you have positive pressure in your crank case because of the location of your oil leak may have forced out your rear cam seal there by oil is flowing out onto your exhaust.
2. What plugs, wires, rotor and cap did you use for your tune up? Your car really like Volvo plugs, Boulibube plug wire and Bosch cap and rotor.
3. I suspect you have a vacuum leak somewhere around your intake manifold or intake air after the air cleaner.

[tryingbe]

I agree with what kahl says.

[Matiss]

Thanks for the quick replies!

Just did the glove test, it does not inflate at all. How long would you suggest to have it on for?

I used Bosch plugs, bougicord 403 class c-1 wires and Bosch rotor.

What's the best way to find the vacuum leak?

[kahl]

Just put on the glove and give the car a rev or two.

[Matiss]

No luck with inflating the glove. The cap does definitely leak oil though, as the glove and now the top of the cap are slick.

[tryingbe]

Take some pictures of your engine and post.

My feeling is that one or more of your PCV hose has popped off.

Read and reset the codes.
https://www.matthewsvolvosite.com/read-codes-volvo-850

[kahl]

Sorry, but I have to ask....did you remove the cap then put the glove on? BTW there is a rubber gasket on the cap that gets hard and does not seal the cap when tightened.

[scot850]

Take the spark plug cover plate off and have a look if there is a lot of oil in there. Also check the PCV hose to the top of the cylinder head is still fitted in place. I have a feeling this may have come off and it then allows oil to flow along the head and there is a slot at the back left (right when standing in front of the car) that allows leaking oil to drain down the back of the engine.

If you don't know when the oil cap seal was last replaced, replace it, especially as a lot of the cheap aftermarket parts go hard and feel like plastic after as little as a year. They then allow oil to leak into the area around the spark plugs also.

Neil.

[wizechatmgr]

Small leak on charge air hoses? The hissing noise - does it increase as it is rev'ed and decrease as you let off the throttle?