Can a leaking oil cap do all that?

volvosurfin · Post by **volvosurfin** » 31 Aug 2011, 23:05

98 v70 T5 Turbo Wag

Today I got the engine compartment torn down enough to replace the cam seals I thought were leaking. The more and more I think about it and look at the oil pattern, the more I wonder if I jumped the gun a bit on the repair.

After I had it for a while, I got a coolant leak w/ some oil from TB cover. Changed waterpump which had a bad gasket and went on my way. Ran okay for a while, still small oil leak behind cover getting sprayed on rear passenger side, then runny cruddy. Not too cruddy, but I thought a PCV overhaul might do the trick. And it did, wow she was running great. Shortly after I starting having same oil spray in rear passenger area without coolant this time, and it was a lot. I had to put 2 quarts in over a week or so, performance got a little worse, so I parked her in the driveway to think.

I had a good amount of oil under the engine cover, Particularly rear drivers side and center. I assumed this was the oil I spilled in my haste to get the volvo full on oil for the way home.

I could see oil on the block towards the rear and about half way around the cam and where it dripped below under TB.

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Once I had the driver side of cam more exposed I could see this. There had been more oil around and inside that I cleaned up while getting to it.

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Then I took a more careful look at the top and saw darker areas of oil(old and dry) inside the groove around the oil cap that runs all the way from left to right, emptying above both cams.

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I had already looked at the cap, which seemed fine. This time I took the seal out and it had plenty small cracks and easily fell apart in my hand.

Could just a cap leak cause this much leak and could it run all the way down both sides of the engine, spraying the back? I'm thinkin yes, but anybody seen this? The cover really never had much in the way of oil on it.

I'd prefer not to change the cams if I don't need too, just wondering if anyone else could confirm that this could indeed be the cap rather than both ends of the cam before I put her all back together.

Post by **taxidad** » 01 Sep 2011, 05:12

It looks to me like it could. I have a leaky oil cap & lifted the O ring slightly revealing the small cracks. I haven't had the cover off, but a fair amount of oil tracks along the groove just underneath. Just from your pictures it looks like the groove empties where the oil where the old oil has collected. I'm waiting for a new cap to arrive, but found that I lessened the leak by turning the cap around. I also found that it was a little tighter not turned to it's full turn. If it was me I'd just clean up the oil, put a new O ring or cap on, run around for a few days & see if that solves the problem first.

mtm3200 · Post by **mtm3200** » 01 Sep 2011, 12:25

I had this same exact problem. I didn't realize it until the check engine light came on and it started trying to stall so i pulled off the cover and there was a lot of oil in all the grooves and it had also gotten into the spark plugs and ruined them. One of them looked like it was submerged in hershey's chocolate syrup. I replaced the cap with an aftermarket one from pepboys and it still seems to leak but I'm hoping that's only because it's a cheap aftermarket cap.

Alwick · Post by **Alwick** » 01 Sep 2011, 13:11

What they said. I replaced the gasket on my cap about a month ago after finding lots of oil pooled underneath the cover.
I haven't bothered to check it since but I do know that the cap has a noticeably tighter seal with a new gasket on it. I would just clean it, replace the gasket and drive it.

Post by **BEJinFbk** » 01 Sep 2011, 14:21

The gasket is cheap. Go for it!

SimLyons · Post by **SimLyons** » 01 Sep 2011, 17:30

IPD (and others, probably) have a flexible (neoprene??) seal that really did the job on my car. Of course I would advise anyone replacing the seal to be sure that the PCV system is OK first. Otherwise you can blow out more seals (like cam) since you have cut off the problem at the oil filler. You don't need the entire cap. Just the seal. And these flex seals don't wear out like the hard OEM seals!

Post by **erikv11** » 02 Sep 2011, 17:30

The OEM seal is also flexible - it is rubber. They only get hard after going a verrrrry long time without being changed.

volvosurfin · Post by **volvosurfin** » 06 Sep 2011, 15:15

Problem fixed.

So I replaced the oil cap seal and no oil under engine cover for about 30 miles, with some pretty demanding conditions. Oil level is stable, no coolant leaks, nadda. So it would seem that yes, a bad oil cap leak can create a situation where it would appear to have a leaking cam seal. Of course this would likely be accompanied by oil under the engine cover.

It was good though that I did the tear down to discover this as I was then able to finish replacing all of my vacuum hoses and other assorted hoses that were bad. Many of the vacuum lines were falling apart, so no doubt I fixed numerous vacuum leaks. The volvo has never run better. No more public transit for me.

Thanks everyone.

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BIG DOG · Post by **BIG DOG** » 06 Sep 2011, 16:50

Yes definetly I had the same thing I was getting oil sprayed around the engine bay.I couldn't figure out what was leaking I was looking around one day and decided it might be the oil cap seal. I cut a new one out of a rubber gasket and my oil spray dissapeared!

Post by **cn90** » 26 Nov 2015, 17:28

I know this is a mundane question but brand for the oil filler cap seal...

Volvo PN 1275379 is about $5-$6. I think it lasts a long time.

Autohausaz, eeuroparts sells the Reinz seal for about $0.60/each.

What is the consensus here re brand?