Question Regarding Oil Leak

Hi all,

After quite awhile without any issues, my truck has an oil leak: '95

5.7, manual trans, 168K miles. The leak is on the driver's side, and there's oil all over the transmission, oil filter, filter housing, and floor pans, and, the leak is leaving a small puddle 4-5 inches in diameter on the ground, directly below the tranny bellhousing.

I retrieved all 32,000 headers outta this group, and read every single one of them pertaining to oil leaks, but didn't see anything pertaining to this issue.

There is no leakage where the oil cooler lines hook into the oil filter adapter unit. They're dry as a bone (that's amazing)....

I first thought a blown intake gasket, or bad sender, but the area behind the distibutor is dry. I bought a sender anyhow just in case.

I changed the oil/filter, and will see if that cures it.

In the mean time, I'm wondering if a bad rear seal could be the cause. I know what to do to check, but are these common? Could it have just been a bad oil filter seal? How do you know if the sender is bad?

Any ideas?

Thanks Rick

Reply to
nobodyhere
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Go under there and clean it all up with a rag and run it for awhile and put a light on it and see where it's coming from.From what you describe it should be easy. Check the back of the engine to see if the oil pressure connection is leaking,or the rear of the valve cover.If you don't see any oil coming down the back,and you do see oil at the bell housing that HASN"T flowed there from the oil pan etc.then you probably have a rear seal leak. This would especially be the case if you only have a leak after driving around,not just idling.

Reply to
cougar

Forget that last sentence.

Reply to
cougar

I had a similar problem, ended up finally seeing some oil coming out of oil filter adapter, now I'm still not sure if I got the whole leak(truck is in garage getting headers, man my knuckles hurt) but man did it slow it down. I got the ES72671 gasket set from felpro but mine is a 7.4 not sure if that fits yours, wierd thing is i only ended up using one o-ring from the set, nothing else fit, but it worked. If you have oil cooler lines coming out with the #*)$*)#($*)#$ quick connects then just buy the new fittings, they are in the help section for 5 bucks apiece trust me you are not gettin those suckers off without breaking em.

cougar wrote:

Reply to
89GMC

Thanks for the reply Cougar. Top of the engine is bone dry. Top of the tranny is bone dry. Oil cooler lines are bone dry, even where they connect to the housing. Oil pan is bone dry. Rear of engine by valve cover gaskets are bone dry.

My BRAIN is bone dry, trying to troubleshoot this thing!

I used the universal cleaning tool (brake clean) and cleaned up the whole area. A week later, it looks as if someone was under there with a spray bottle of oil...

The only thing that's wet, is the oil filter housing, oil filter, and everything around it, including the tranny inspection plate, the side of the tranny (driver's side only), the floor pans, the frame, the fuel lines, brake lines, etc. Guess those will never rust...

So, I'm thinking one of two things: bad rear seal, or the filter housing to block surface is leaking. There is a gasket kit for this, and I assume it's a relatively easy fix.

I understand the rear seal can be replaced without dropping the pan, IF you have the seal-driver tool.

Anyone have any idea where to get one? Don't want to go to the truck for this one...

Thanks Rick

Reply to
nobodyhere

Thanks 89GMC - I posted up a reply before I saw yours. I'm leaning toward the housing thing, but want to be prepared for a rear seal replacement if I have to.

I'm probably going to make a lot of people mad, but the quick connects were designed by people who were spawned from the devil. I could never, ever, see the use or advantage to having them. Rick

Reply to
nobodyhere

OK. I was thinking more like 15 minutes of run-time after clean-up to pin-point the leak.After a week the picture is too fuzzy,although your filter seal theory is possible.I had this happen on a 5.7 that had an adapter there.

Reply to
cougar

"I'm probably going to make a lot of people mad, but the quick connects

were designed by people who were spawned from the devil. I could never, ever, see the use or advantage to having them. Rick"

AMEN, i invented some new swear words for those things....

Reply to
89GMC

OK, here's the fix... Advance Auto P/N ES72671, and 15 minutes of time... Couldn't have been any easier! The gasket and O ring were destroyed... Used a 3M prep pad on the gasket surface to clean.

As far as the rear seal, everything behind the inspection plate was a dry as a bone...

I also used bbq grill cleaner from BJ's to get rid of all of the oil buildup. Spray it on, leave it for 10 mins, hose it off and the undercarriage is like new.

Thanks to all who replied. Rick

Reply to
CHEVYDRIVER37.AT.YAYHOO.COM

I hope what ever you used the 3M prep pad on was not a part of the engine, ie the block. Those things are loaded with a very fine to some what coarse aluminum oxide. Its not the scotch pad that does the cleaning its the aluminum, and it has a tendency to get into places you really dont want it. When they first came out we thought they were the greatest thing since sliced bread. Then we started seeing bearing failures, washed out cam shafts, chewed up lifters etc. Now then for things off the engine that can be cleaned in a parts washer or hosed down good, like timing covers, valve covers, intake manifolds, water pumps, etc, they are still the greatest thing since sliced bread.

Whitelightning

Reply to
Whitelightning

Whitelightning - Oooops! I guess I should've been more specific... It was actually a sanding pad (I call 'em prep pads, but I know, there's a difference), and I just lightly cleaned the gasket gunk off the adapter surface, nice and slow, at +/- 30 psi. The mounting surface up in the block was clean, so that was just a thorough cleaning, to be sure nothing was stuck up in there.

Rick

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Reply to
CHEVYDRIVER37.AT.YAYHOO.COM

Rick,

Glad to hear you got it fixed, always nice to see what the outcome is, sounds like you had the exact same leak I did then... what was odd with mine(big block) is i only needed the o-ring, the other gasket was up in there but went against nothing... b/c the only place the adapter hit the block was where the big o-ring went.... Oh well no more leak and no more gasket randomly floating around up there.

CHEVYDRIVER37.AT.YAYHOO.COM wrote:

Reply to
89GMC

Yeah, that leak troubled me for awhile. I get nervous when things aren't readily apparent. Well, it's all fixed... Saw the new '07 tonite. I must have this truck. I will abuse, er, uh, test drive one this week. Might have to take the painful steps of a monthly payment again.

Rick

Reply to
CHEVYDRIVER37.AT.YAYHOO.COM

Hey let me know how it test drives, I haven't heard any hands on about those yet.

Reply to
89GMC

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