Oil leak Gurus please respond
Thread Starter
Instructor
Joined: Aug 2003
Posts: 109
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From: Milford CT
Oil leak Gurus please respond
I have a new to me 94 LT1, 6 speed with oil leaking on the floor. Here’s what I’ve done so far. I took off the starter, looked and felt the side of the block near the valve cover gaskets. Seems dry there on both sides. Oil pressure sender looks ok. I viewed that with a mirror it’s not leaking there. There are drops on the bottom of the started and there is also drops coming out or the bottom of the bell housing. I removed the inspection cover and the inside of the bell housing is very juicy/ wet. This seems like a rear main seal. Any thoughts.
The whole oil pan is wet on the bottom. The cross member in the front of the engine is also wet. It looks like I’ve got a leak up front somewhere but this is much harder to see.
Any thoughts on what might be leaking up front?
I thought of getting a black light setup. Anyone used one of these for oil leak discovery? Where is the best place to purchase one?
Has anyone re-torqued the oil pan bolts and had leaks stop?
I figure to do the rear main, and a clutch while I’m at it when I stop driving the car for the winter. I’d like to do all the leak fixing at one time, that’s why I thought of the leak detection kit.
Any information is greatly appreciated. This is a great forum. I wish I had this in the 80s when I owned a total of 15 C3s.
The whole oil pan is wet on the bottom. The cross member in the front of the engine is also wet. It looks like I’ve got a leak up front somewhere but this is much harder to see.
Any thoughts on what might be leaking up front?
I thought of getting a black light setup. Anyone used one of these for oil leak discovery? Where is the best place to purchase one?
Has anyone re-torqued the oil pan bolts and had leaks stop?
I figure to do the rear main, and a clutch while I’m at it when I stop driving the car for the winter. I’d like to do all the leak fixing at one time, that’s why I thought of the leak detection kit.
Any information is greatly appreciated. This is a great forum. I wish I had this in the 80s when I owned a total of 15 C3s.
Pro
Joined: Apr 2000
Posts: 621
Likes: 1
From: Clarkston Mi
Re: Oil leak Gurus please respond (Thomastp)
First, welcome to the forum.
I too have LT1/ZF6 setup. Luckly for you - the trans is not very hard to remove - this indeed sounds like a rear main seal issue. I personally would not reccomend "re-torqueing (sp?)" the bolts on your pan, if your pan is leaking, synthetic oil has a way of getting out no matter what, replace the pan gasket while it is down. The service manual says that you cannot remove the pan with the engine in the cradle, but you can, you have to turn the engine to do so, the crank gets in the way. Best of luck!
I too have LT1/ZF6 setup. Luckly for you - the trans is not very hard to remove - this indeed sounds like a rear main seal issue. I personally would not reccomend "re-torqueing (sp?)" the bolts on your pan, if your pan is leaking, synthetic oil has a way of getting out no matter what, replace the pan gasket while it is down. The service manual says that you cannot remove the pan with the engine in the cradle, but you can, you have to turn the engine to do so, the crank gets in the way. Best of luck!
Racer
Joined: Apr 2003
Posts: 304
Likes: 0
From: Tulsa OK
Re: Oil leak Gurus please respond (Thomastp)
it could be the rear intake manifold leaking which is a very common problem on chevy 350....check on the top back of engine and see if it is wet and if so its most likely coming from there and not the rear seal
Le Mans Master
Joined: May 2003
Posts: 5,203
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From: Las Vegas Nevada
Re: Oil leak Gurus please respond (Robey5)
:iagree: But...I would replace the pan gasket with the new felpro blue silicone.....works great. May just be the pan gasket. RMS might just be fine. And I beleive if you prep the surfaces before putting on silicone gasket...even syn oil will stay put.
[Modified by Southern Comfort, 3:35 PM 9/15/2003]
[Modified by Southern Comfort, 3:35 PM 9/15/2003]
Racer
Joined: Apr 2003
Posts: 280
Likes: 0
From: edmonton ab
Re: Oil leak Gurus please respond (Thomastp)
[B][
Any information is greatly appreciated. This is a great forum. I wish I had this in the 80s when I owned a total of 15 C3s
i guess to get the best black light set for your problem is to elimintate those strips of "ice" first....... :lolg: :lolg: :lolg: :lolg: :lolg: :lolg: .....then try your snap on "dealer" for a new line....lol
Melting Slicks
Joined: Oct 1999
Posts: 2,501
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From: Houston, Texas FEAR THE BONES
2023 C5 of the Year Finalist - Modified
Re: Oil leak Gurus please respond (vettek50)
Thomas,
I too have a '94 ZF6 with what sounds like the same oil leak. I have oil on th front crossmember, which streams back along the oil pan and accumulates on the bell housing and oil filter. It drips on the floor at the cross member and at the bellhousing.
I did have an oil leak at the oil filter assembly, but that was easily fixed by reinstalling the asembly and making sure the oil filter rubber seal was correclty seated.
So far, I have repalced the oil pan gasket, the timing cover gasket, the Opti seal, the water pump drive seal, the front crank seal (with a Speedi Sleeve over the crank snout), and the intake manifold gaskets. None of these repairs have cured the leak :crazy: :banghead: . I dropped the car at the Chevy dealer this morning for an oil leak test (I did one myself at home, but I could not pinpoint the source). I will post results. Good luck with the leak (hope it is not a rear main seal) :cheers:
I too have a '94 ZF6 with what sounds like the same oil leak. I have oil on th front crossmember, which streams back along the oil pan and accumulates on the bell housing and oil filter. It drips on the floor at the cross member and at the bellhousing.
I did have an oil leak at the oil filter assembly, but that was easily fixed by reinstalling the asembly and making sure the oil filter rubber seal was correclty seated.
So far, I have repalced the oil pan gasket, the timing cover gasket, the Opti seal, the water pump drive seal, the front crank seal (with a Speedi Sleeve over the crank snout), and the intake manifold gaskets. None of these repairs have cured the leak :crazy: :banghead: . I dropped the car at the Chevy dealer this morning for an oil leak test (I did one myself at home, but I could not pinpoint the source). I will post results. Good luck with the leak (hope it is not a rear main seal) :cheers:
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Race Director
Joined: Feb 2003
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From: Lake Wylie SC
Re: Oil leak Gurus please respond (Thomastp)
I have a 92 LT-1 6spd and mine leaked as you described. I also thought I had a rear main leak. I had to replace the water pump and opti and removed the timing cover and had to remove the oil pan. After replacing the oil pan and timing cover gaskets along with the timing cover seal, I think I have the oil leaks contained. No you don't have to remove the engine to remove the oil pan. See my tech tip. tools>tech tips>C4>Meziere pump install. It will tell you how to remove the oil pan. As mentioned before, the oil was streaming backwards as the car was driven, as my leaks were from the water pump driven gear seal and opti seal in the timing cover. DON'T RETORQUE YOUR OIL PAN BOLTS......YOU'LL PROBABLY BREAK THEM
Team Owner
Joined: Oct 2000
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From: Fort Knox, KY
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Re: Oil leak Gurus please respond (Strick)
Check your PS resovoir-to-rack pipe, too. Mine was actually leaking worse on my 1992 than my intake manifold gasket. Check the intake, too. They are especially prone to leaking from the front or rear on LT1/LT4 engines.
For the intake gasket, use copper RTV silicone sealant or a product called "The Right Stuff" you can get at NAPA. Get the Fel-Pro gasket kit for around $11.00 at your local auto parts store. Tack it down good and proper, and you won't have those leaks anymore. :thumbs:
For the intake gasket, use copper RTV silicone sealant or a product called "The Right Stuff" you can get at NAPA. Get the Fel-Pro gasket kit for around $11.00 at your local auto parts store. Tack it down good and proper, and you won't have those leaks anymore. :thumbs:
Safety Car
Joined: Feb 1999
Posts: 3,504
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From: Mexico Beach FL
Re: Oil leak Gurus please respond (onedef92)
Most common cause of leaks: the intake manifold either front or rear.
GM has a Technical Service Bulletin on the expansion plug at the rear of the cam inside the bellhousing for leaking -- I haven't heard of anyone having this problem though.
Tom Piper
GM has a Technical Service Bulletin on the expansion plug at the rear of the cam inside the bellhousing for leaking -- I haven't heard of anyone having this problem though.
Tom Piper
