Volvo Guys -- Sudden Oil Leak and Rough Running

[CJFusco]

Hey all -- I have a sudden, without-warning issue with my 1997 Volvo 850 Wagon (non-turbo, automatic transmission), and I was wondering if any of you had any ideas. I've owned the car for about 15 months, and it has 263,000 miles. Over this time, I've replaced the PCV system and had a shop replace the AC Compressor (which was making very unpleasant noises). I've posted this on a couple of Volvo-specific boards as well, but I usually get a quicker, more detailed response at Pelican than anywhere else.

Yesterday, I went out to the garage, and saw a pretty sizeable puddle of oil underneath the driver's side of engine, near the back of the block. There was oil everywhere, so it was difficult to tell where the oil was coming from, but the highest point where oil is visible is a small circular protrusion off the driver's side of the engine, under the motor mount (see picture). In the photo, you can see how the lower bolt is darker (oil-covered) than the upper bolt. I'm not sure this is where the oil leak is occurring, but it looks like there's oil there.

I went out to the driveway, and sure enough, there was a small spot of oil where the car was standing while I waited for the garage door to open the night before. There were also several small dots of oil leading up the driveway along the path that I would've driven that night. But here's the weird part: there was no oil spot at the bottom of the driveway, where I would have parked for a minute or so to get the mail. There is a little bit of a bump/ledge halfway up my driveway, where the driveway goes from gravel to asphalt; part of me wonders if going over this bump knocked something loose to cause the oil leak.

I checked the oil level and it looked to be about a quart low, so I added more oil. Then I started the car to check to see if I could see it leaking. It ran fine at first, but the longer it idled, the worse it ran. It developed a "hitch" in its idle, almost as though one of the five cylinders wasn't firing correctly. At first, revving the engine slightly caused it to even out; after letting it run for a few minutes, though, it began to stumble under load. There was no check-engine light tripped on the dash. I removed the plastic spark plug cover, and it was bone-dry under there. There was the usual amount of exhaust from the tailpipe -- no more smoke than usual, and none of the blue smoke that usually denotes burning oil nor the white smoke that denotes a blown head gasket.

Here's the weird part: looking for fresh oil drips, there seems to be very little. There is a small spot on the new cardboard I put under the car, but I can't be sure this isn't excess oil dripping off the bottom part of the engine, frame, axle, etc. Letting the car run for a bit (at least until it was warm) caused a slight oil spot, but nothing I'd be concerned about if it occurred in isolation. I went ahead and moved the car into the driveway so my wife could have her garage spot back. The car stumbled a bit under load, but I was able to park it in the driveway without incident.

This morning, in the driveway, there was a small oil spot under the engine, but nothing alarming. I started the car, and it fired right up. It ran well for a minute or two, but then the idle got progressively worse. When I tried to rev the engine, it stumbled much more noticeably than yesterday, and the "check engine" light came on. At this point, I reconciled with the fact that I would need to have the car towed to a shop. Considering this, I put it in reverse so I could position it better for the tow truck, but the engine died after putting it in gear. I tried to start it again, but it started then immediately died. There was a little new oil on the cardboard under the engine, but, again, not enough to be alarming.

This seems to me a bizarre set of symptoms. Why would it leak a bunch of oil right away, but then not so much the next day? And why would an oil leak cause rough running, but only after the car warms up? Any insights that anyone could provide would be well appreciated.

[TRE Cup]

Hi. Don't know if this applies to a 97, but we had a 740 turbo wagon come in with a similar problem. There is an anti backfire round "filter" in the rubber fitting that attaches low on the block. The hose went from there to the breather system. This quarter sized "biscuit" just pressed into the hose that attached to the block.

Hope this is helpful

[Bowling]

The inline 5 cylinder motors tend to burn valves and oil, there is also a rear seal that may deteriorate and leak from the oil pump. I had a 95 and a 97.

[1990C4S]

The PCV system is blocked. Pull that camshaft sensor off and you will see the camshaft seal has been pushed out. Oil will be gushing out there.

I will put $100 on it...

Normal Volvo issue.

[LEAKYSEALS951]

I'll throw in a long shot idea behind the blown gasket due to a clogged pcv theory-
You said the pcv was replaced recently.
My bet, it that something has come loose in the intake or pcv system.
When it came loose, oil splattered everywhere.
As it gets looser- more unmetered air is getting in the system, and making idle progressively worse.
Since it blew it's "wad" of oil- you won't see much more leaking out, as you have mentioned.

I've had this happen on my volvo and on my 944 turbo, where an intercooler pipe blew loose. The cars still ran- but ran like crap, especially at low revs. In both cases- I was able to get the cars home only to open the hood and stare in wonder and amazement that they ran at all with the loose pipes.

Just a thought

[CJFusco]

Thanks for the replies, guys. Yeah, part of me did wonder if some part of the PCV system did come loose in the driveway... it's just such a PITA getting to the PCV system; so much stuff on top of the engine needs to come off.

As this is looking like a busy week, I might have to have the car towed to the local Volvo place. If it was the summertime, I would just start poking around until I figured out what's going on. Ah the life of a teacher...

[1990C4S]

That cover is super easy to remove, you will will know in five minutes if that is the issue.

Don't tow the car for that.

[Bowling]

You mentioned you already replaced the PVC system, I agree with the others, that's the first place I'd look.

[dafischer]

All of those symptoms point to a PCV system issue, more of a problem on Turbo models, vs a NA car, but they still occur.

Parts availability from FCP Euro, where I get most of my Volvo stuff.
https://www.*******.com/Volvo-parts/850?year=1997&e=153&m=20&keywords=pcv

No connection, just a satisfied customer.

[LEAKYSEALS951]

Please update when you find the answer.
I think there is a leak in my system somewhere and it is driving me CRAZY!
Like you said- the PCV system is hard to access.

Like you, I replaced the PCV about a year ago, but the idling issue has returned- only when warm. My thought is that the engine richens the mixture when cold and that compensates for the leak, but when warm, it is not enough to compensate- so it runs like you described.

It would be interesting if it was the cam seal letting in air, because for the love of god I cannot find a pcv or intake leak of any kind and I am at the point where I am going to punt it to a shop!!!!

[Nostril Cheese]

I also say PCV

[CJFusco]

Well, the Pelican Braintrust has hit another home run. Here's what happened:

Somehow, one of the PCV breather hoses got pinched/crimped, which built up pressure in the crankcase, causing the cam sensor gasket to blow out, dumping oil all over my garage floor all at once. The car is good as new now. The garage floor? Well, at least it will be painted and sealed this Summer.

Thanks again for the input.

[LEAKYSEALS951]

Thanks for posting.
This gives me some ideas for my own car.
When I replaced the pcv system the first time, due to the tight space, I inadvertently kinked and split the plastic vacuum line that comes off that banjo bolt under the intake manifold. The SECOND time I did it, I tried to make sure nothing got torn/stretched/ and or kinked. Oil has been leaking off the block- perhaps I blew out the cam seal too. I kind of hope I did. I need some resolution!

[Scott Douglas]

CJ - Go to Pep Boys and get some Oil Eater cleaning fluid. It'll clean that floor up nice for you.

[1990C4S]

I want my $100.

[CJFusco]

Thanks again for the tips. 1990C4S, your payment is in the mail in the form of expired Orange Julius gift cards.