Leaky Oil Cap

ir637113 · Post by **ir637113** » 19 Feb 2018, 11:27

Recently replaced the oil trap and associated hoses on my 850 wagon. Noticed shortly thereafter that the seal on my oil cap was busted, so I replaced that. Went to go spray off the engine today, and when I popped the hood with the engine running, I noticed pill spill out from under the cap when I hit the gas.

So my question is basically what could cause it and/or what do I do? Brand New PCV (minus the breather hose that goes up under the spark plug cover because that was replaced in November), so unless I got a shit deal (it was a URO, so who knows?), It shouldn't be building up so much pressure. Is this a common problem y'all have?

The only suggestion I found when I googled it was to buy some gasket sealer/maker and basically fill in the portions of the cap where the current gasket doesn't reach.

Post by **abscate** » 19 Feb 2018, 11:56

The block passageway can plug on these cars, which will give you high crankcase pressure. Don't drive it like this with pressure, you will blow out your cam seals or your rear main engine seal (RMS) which costs $5 in parts, and $1000 in labor, to repair.

ir637113 · Post by **ir637113** » 19 Feb 2018, 12:15

abscate wrote: ↑19 Feb 2018, 11:56 The block passageway can plug on these cars, which will give you high crankcase pressure. Don't drive it like this with pressure, you will blow out your cam seals or your rear main engine seal (RMS) which costs $5 in parts, and $1000 in labor, to repair.

Already blew the cams and RMS. Already know the car's basically no longer my daily driver lol. I just need it to not spray 4 quarts of oil out of the cap every day.

It's just weird because I replaced the oil trap and associated hoses like, two weeks ago.

Post by **scot850** » 19 Feb 2018, 12:19

Do the glove test on the oil filler. If the glove inflates, then you didn't get the PCV system cleaned correctly.

Otherwise you may have a bad cylinder or pressurizing from the crankcase due to engine wear.

Nel.

ir637113 · Post by **ir637113** » 19 Feb 2018, 12:35

scot850 wrote: ↑19 Feb 2018, 12:19 Do the glove test on the oil filler. If the glove inflates, then you didn't get the PCV system cleaned correctly.

Otherwise you may have a bad cylinder or pressurizing from the crankcase due to engine wear.

Nel.

Definitely will check. But I think I figured it out. The gasket on my oil cap is really loose. A lot looser than I've seen on oil caps on my other Volvos. So hopefully easy fix

Post by **scot850** » 19 Feb 2018, 12:39

I use only Volvo part for this. Yes it is more expensive but they last longer but should be swapped ever 3 years or so or when they become hardened or start leaking. I have seen one where the oil filler cap tabs were bent meaning the cap wouldn't tighten down fully.

Neil.

Post by **erikv11** » 19 Feb 2018, 12:45

Be careful, the problem may not be just the cap or gasket, but the crankcase pressure. Frequently the drain passages from the PCV oil trap box into the block, are completely coked up and clogged.

ir637113 · Post by **ir637113** » 19 Feb 2018, 13:02

erikv11 wrote: ↑19 Feb 2018, 12:45 Be careful, the problem may not be just the cap or gasket, but the crankcase pressure. Frequently the drain passages from the PCV oil trap box into the block, are completely coked up and clogged.

Yeah they were shit when I went and did it. Put a glove on there and it blew right up. Here's my question - is it 100% accurate as a way to diagnose that?

If so, I can take it apart and try cleaning the ports again. What does everyone use to do that? I basically chiseled what I could out but the ports take a hard 90 about an inch into the block.

I'm also just debating saying screw it haha. With a bad RMS and cam seals, this thing is gonna lose me at least a quart a week as is. Although I put blue devil in.... Idk. I'm just tired of working on this damn thing.

As far as using genuine Volvo parts.... Yeah I totally would... Except doing that probably means someone isn't eating, and this car is already on the short list to get chopped.

Post by **RickHaleParker** » 19 Feb 2018, 13:06

The gasket on my oil cap is really loose. A lot looser than I've seen on oil caps on my other Volvos. So hopefully easy fix

Take a Tack Hammer and move the two tabs on the cap slightly.

ir637113 · Post by **ir637113** » 19 Feb 2018, 13:06

erikv11 wrote: ↑19 Feb 2018, 12:45 Be careful, the problem may not be just the cap or gasket, but the crankcase pressure. Frequently the drain passages from the PCV oil trap box into the block, are completely coked up and clogged.

What's the best way to clean those passages? Robert said something about pipe cleaners, but I'm having trouble visualizing that, especially considering the build up I ran into was almost rock hard.