What Material Should I Use for the Oil Pump Gasket?
So, I posted here a little while ago about my oil pressure taking a couple seconds to move from zero whenever I started my Jeep cold. I was told that this was normal, and not to worry about it.
I haven't been worrying until today, when it occurred to me that when I had my oil pump out a few weeks ago, I may have compromised the seal on the gasket where the pump meets the block. This thought was corroborated when I started my Jeep and listened. I heard a hissing (sucking?) noise for a second or so, and then it stopped right as the oil pressure gauge moved up.
So, I think that the failing gasket is allowing air in, and the oil is draining back down the pickup tube when the Jeep sits for a long time.
Anyway, I'm planning on dropping the pan again and replacing the gasket.
So two questions: First off, does my analysis of the noise sound correct?
And more importantly: What is the best material to use for a gasket? Will grey RTV work, or should I use that paper-type gasket material maybe? I would just buy the gasket if I could, but it seems it's not available unless I buy an entire rebuild kit for $30.
The oil will always run back down the pickup tube when you turn the engine off, there's no check valve on the pump suction.
I would use a thin paper gasket, as opposed to RTV.
I don't know about the hissing (if no gasket, it may be caused by pressure, not suction since those mating surfaces are on the pump's discharge), but I do know the oil pressure gauge takes a second to come up on any vehicle I've ever owned.
-Steve "Those who hammer their guns into plows, will plow for those who do not." -Thomas Jefferson
'98 ZJ Laredo 5.2 Selec-Trac (249 to 242 swap)
'05 KJ Limited 3.7 Selec-Trac
'94 ZJ Limited 5.2 Q-Trac- sold, after 17 years
'67 International Harvester Scout 800; 345ci V8,T18 4spd, Dana 20 TC
'06 Chrysler 300C SRT8 6.1L
The IAC makes a hissing noise upon start up. There's no gasket between the block and the oil pump. It's not a crucial sealing point, so the two machined surfaces do just fine. Some high performance engines with high volume/pressure pumps use a copper gasket, but that's it. You wouldn't want a regular gasket there because if it were to blow out, you would be left with a gap for oil to escape.
Mine has a gasket, looks like the usual paper stuff. So I thought perhaps for some reason a good seal was necessary at that point. But I won't worry about it if it's non-crucial, it's starting to get cold around here! Not a good time to rip into my engine if it's not necessary.