Common places for oil leaks

[Captainblastem]

Hello All,

So I believe I have all the oil leaks narrowed down on my '90. The oil pressure switch was leaking, the oil level switch is still leaking, and there appears to be oil dripping down the rear side of the oil pan. Initially I thought it was the rear main seal, but looking closer, it might just be the oil pan gasket. My question is: do the oil pans on these engines typically leak on the front and rear? Is this a common occurrence as these engines gain miles? Do the front and rear main seals tend to leak as well near 100k miles, or does that not typically happen?
Cheers,
- Rob

 

[Irish Pride]

Hello All,

So I believe I have all the oil leaks narrowed down on my '90. The oil pressure switch was leaking, the oil level switch is still leaking, and there appears to be oil dripping down the rear side of the oil pan. Initially I thought it was the rear main seal, but looking closer, it might just be the oil pan gasket. My question is: do the oil pans on these engines typically leak on the front and rear? Is this a common occurrence as these engines gain miles? Do the front and rear main seals tend to leak as well near 100k miles, or does that not typically happen?
Cheers,
- Rob

Oil on the rear of the pan will more than likely be from the front main seal. The cam seals tend to be a very common spot for leaks too. When the cam seals leak you will usually smell it. It will drip down on to the Y pipe.

 

[msteiny]

My oil level sending unit have been replaced with a bolt, no more leak. I prefer to check my oil the old fashion way than rely on that set up anyway.

 

[rubydist]

remember that the oil pan gasket on these engines is rtv along the sides of the pan and a short piece of rubber around the bearing cap at each end. the rtv very seldom begins to leak over time, but the rubber piece will eventually shrink, and I have seen leaks at the ends of the rubber pieces, on both front and rear end of the engine. so it is possible that the oil leak is from the pan gasket setup.

however, as was pointed out above, the crank seals and cam seals are well-known to become leakers with age, and that is the more likely candidate.

 

[jimtash]

Don't pay attention to mileage but age. My '98 V-8 has 86,000 miles but the valve cover gaskets leaked until I replaced them. Time and heat take a toll on gaskets and seals.

 

[Captainblastem]

Thank you for the responses.
Just to be clear, oil is leaking from the rear of the engine, right in between the oil pan and the transmission bellhousing. It looks like it coming from the top of the Oil pan, but it's really hard to be sure. I know that leaking cam seals would only effect the front side of the engine (which I already addressed earlier in the year). Oil doesn't seem to be dripping from the heads themselves, so I figured it was the rear main seal, or the back of the oil pan right next to the trans. I don't suppose there is a sure way to tell if it's the rear main? Either way, there is going to be some work involved, but I'd rather not have to pull the engine & trans unless I need to.
-Rob

 

[rubydist]

Normally, the rear main seal leaks into the bellhousing so it appears to be coming from the bottom of the transmission. From your description, there is a good chance it is the pan seal that has shrunk up and is leaking at the end of the rubber piece at the rear of the engine.

 

[jimtash]

If you're going to replace the oil pan gaskets, do the rod bearings while you're in there.

 

[Captainblastem]

Thank you all for the replies. I'm dropping the pan this week to have a look....Jimtash, yeah I was pondering that, and it would probably be a good idea.

 

[Captainblastem]

Anyone ever tried any alternate oil pan gaskets? I noticed rock auto has a couple 1-piece gaskets that look like they're of decent quality.

 

[kevinspann]

Anyone ever tried any alternate oil pan gaskets? I noticed rock auto has a couple 1-piece gaskets that look like they're of decent quality.

They're not correct for the SHO.

 

[rubydist]

there are no alternates.

 

[Captainblastem]

http://www.amazon.com/Magnum-OS21014-MaxDry-Oil-Gasket/dp/B007TGKD5A
That looks like the right bolt pattern...?

 

[SHOtime2511]

It says it "does not fit" when I checked with a 91 and a 95 atx

 

[rubydist]

it is not the right part.

 

[Captainblastem]

rubydist: You're right...I got a good look at the oil pan bolt pattern once I took it off. Definitely different. Also, I took a look at the rod bearings:

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Looks like they need replacing boo

 

[kevinspann]

Huh? Those bearings look great. What kind of markings do they have on them?

 

[luigisho]

Yeah. Those look pretty good. That's normal wear.

 

[Captainblastem]

wear spots showing like that on ONE side is normal?

 

[Captainblastem]

I'll take some more pictures tonight of the rest of them and post it here.. thanks for the input guys. I come from working on muscle cars and this is my first SHO, so go easy on me lol....

Also, backside of bearings have scratches on them, which could be from dirt and unclean oil. I think the previous owner did a poor job keeping up on oil changes.
~Rob