Hi,

Im a owner of a 850 95 non turbo since August 16 2000. The first day I got it, I went to a mechanic and change oil. The mechanic remark that there was oil under the spark plug cap. He suggest me to replace the seal of the engine oil cover for a buck or two. At this point, I've start checking my oil every two day (to make sure all is ok) and I remark (after 1000 km) that the car loose some oil. I also remark that sometime, in the cabin, it smell burn oil. I check the engine carefully (mean outside the engine) and see nothing. Mechanic told me about a valve for extra pressure. Anyone have an idea of what it can be?

Thanks in advance,

Bruno

Both of our cars (855 and S70) burn about a half quart every

3000 miles. I check the oil level when ever I check air

pressure to keep an eye on it.

The "Valve" may be the Flame Trap. It needs to be cleaned

annualy to avoid problems with the engine's main seal.

See http://www.volvospeed.com/Repair/ftrap.htm for instructions

on how to clean it.

Just how much are you loosing?

According to Volvo, the 850 can consume up to .5 quarts every 5000 miles (or is it 3000? If you want, reply and I'll put the accurate numbers up. Don't have them with me right now).

After replacing the seal, do you still see oil leakage?

The seal on the filler cap could be causing the problem alone. It is a common reason for oil under the spark plug cover.

What about compression? You could be loosing oil through the spark plug openings. Not likely if you don't notice a decrease in performance and a check engine light.

I had a mechanic check my oil level during routine maintenance, and he didn't put the dip stick back in properly. Later that day, I noticed the smell of burning oil. Oil splurged out the dipstick all over the top of the engine. It took me nearly 3 hours to get the varnish like oil off the engine, with tonnes of degreaser.

It's good that you are checking on the oil level frequently right now. Keep doing so until you are certain you aren't loosing oil anymore. BTW, are you using a lint free cloth and NOT paper towel to wipe the dipstick? Fibres from the paper towel get into the engine, so use a lint free cloth.

Regarding the "valve for extra pressure," can you be more specific? Is he talking about a crankcase valve, flame trap, etc.

Sometimes, excessive crankcase pressure occurs creating positive pressure in the engine in areas not intended beyond threshold that forces oil through seals.

And sometimes, a deteriorated/dirty flame trap causes oil to spew into the intake.

Last week I posted about excessive crankcase pressure blowing oil out of my dipstick tube and presumably making my rear main seal seep. Being that I've got a trubo and thus no flame trap, some suggested that I clean out the throttle body and every vacume line connected. The snow has kept me from trying it. Does anybody else have anything else that can cause this problem. I truly think that when I bought the car it had a leaking filler cap. When I replaced that seal I pressurized the system and that pressure's got to go somewhere now...

Does anybody know of a rear main seal stopping its seeping after fixing the cause of excessive pressure? (or once it's breached it forever doomed?)

Also any other ideas on the cause of this excessive pressure? I'm stumped

> Just how much are you loosing?

about .5 litter per 1500km (synthetic oil, castrol syntec)

> After replacing the seal, do you still see oil leakage?

seem to be ok now... but didn't check since 3 month

Hi, thanks for replying,

Here what I've got to anwser from your question.

> What about compression? You could be loosing oil through the spark

> plug openings. Not likely if you don't notice a decrease in

> performance and a check engine light.

Im not equiped to check compression... (i will be soon) Didn't have check engine light and performance seems to be fine (I didn't try other volvo since last years except mine... hard to tell)

For the oil stick, I had the same problem. I just put it in place and I stil have a lot of clean up to do... damm.

> Regarding the "valve for extra pressure," can you be more

> specific? Is he talking about a crankcase valve, flame trap, etc.

Hes talking about a valve that should be in the oil pump. I also heard about flame trap... but dont know what is for...

I think that I had to take a look at many places under the hood... Maybe I should dress up a list. I must not forget that I saw a small leak at the back left of the engine that was very easy to see from the rotor with the wheel removed.