oil leak - Chevrolet Forum - Chevy Enthusiasts Forums

oil leak

Join Date: Feb 2008
Posts: 14

February 2nd, 2008, 1:22 PM   #1  
oil leak

My 2000 silverado 2wd 4.8 is leaking oil. I cleaned the engine and it appears to be coming from between the engine and transmission. Is that going to be a rear main seal leak? If so how hard of a fix is that?

Join Date: Jul 2006
Posts: 504

February 3rd, 2008, 6:39 PM   #2  
RE: oil leak

Is it engine oil or transmission oil?
If transmission then you need to at the least pull the tranny back and replace the imput seal. Not too bad.
If it's the engine, and not to bad it's probably the u seal on the pan. Rear mains uaually leak really bad. They get changed a lot when they don't need to be.
If it's the engine try 1/2 to full quart of marvel mystery oil on your next oil change. If it doesn't stop it, it will be really close.
It will also help clean out a lot of sludge, and varnish in your oil system.

Join Date: Feb 2008
Posts: 14

February 3rd, 2008, 11:07 PM   #3  
RE: oil leak

I replaced the rear main seal and the u seal. Drove it around and it appears to still be leaking. I removed the inspection hole cover on the transmission and it looked like the oil was coming from just forward of the flywheel (right where the rear seal is). I also inspected the intake and it looked dry. What else could it be?

Join Date: Nov 2007
Posts: 95

February 4th, 2008, 9:58 AM   #4  
RE: oil leak

I would assume that if you pull the tranny back, then spray every oily area, on the engine and tranny, excesivley with carb or brake cleaner (this will remove ALL oil and dry it out) then sit back and wait for the littlest bit of oil to show, and that is exacltly where you're leak is coming from. you may have to reconnect the trany and drive it a mille or two to get the leak flowing, but it should get r done. thats what i would do.

Join Date: Feb 2008
Posts: 14

February 4th, 2008, 10:27 AM   #5  
RE: oil leak

I did clean the oil off. And when I put it back together and drove it, it appeared to be dripping from the rear seal, but I can't actually see the seal with the flywheel in the way. Is there anything else that could be leaking?

Join Date: Jan 2007
Posts: 424

February 4th, 2008, 3:08 PM   #6  
RE: oil leak

The intake manifold could be leaking at the rear of the engine. When it leaks there, it's difficult to tell where it's coming from. Check the top rear of the engine to make sure it's not leaking above the transmission.

Join Date: Feb 2008
Posts: 14

February 6th, 2008, 1:41 AM   #7  
RE: oil leak

I inspected the intake manifold at the rear of the engine it is not leaking. Could the transmission shaft be warped causing it to not seal well?

Join Date: Feb 2008
Posts: 138

February 10th, 2008, 9:23 PM   #8  
RE: oil leak

on these chevys getting that u seal on right is a pain in the ***, if you dont put it on just right it will still leak. and as far as the rear main its pretty much the same, it needs alot of lube when putting it back in, all it needs is a little slice in that gasket and it will still leak.. try taking that inspection plate off and letting the car run and sit under there with a flash light. also you can go to your parts store and get an oil leal dye detector and poor it in the oil and get under there with a black light and the oil will glow a neon color from where it is leaking. that come in handy at work when we have big oil leaks.. hope this helps


K1500notSilverado's Avatar
CF Beginner

Join Date: Sep 2009
Posts: 10

October 19th, 2009, 1:09 AM   #9  
me too..

First off, thats a glorious picture KCB37, looks like me and you would get along fine with our trucks. But getting down to business: My rear main is leaking on my '97 K1500 (350, automatic), I changed the oil 2 days ago and added some Lucas oil thats sopposed to help with leaks, but today it seems like it got worse, in fact I could see it dripping pretty good at one point. Should I wait a little while longer and see if it slows down? I hear the job is really expensive, how much should I expect to shell out?

Thanks and Gig 'Em,

Drwprince's Avatar
CF Beginner

Join Date: Apr 2012
Posts: 1

April 18th, 2012, 4:29 AM   #10  
I realize this post is quite old but...

There is also a oil pressure sender/switch that can rapidly leak oil if it become defective. Its located behind the intake manifold between the block and the firewall and is kind of a pain to find but chances are if its covered in oil then thats where your leak is coming from. The oil will run down the back of the block and between the oil pan and transmission making it tricky to track down. These parts only run between $20 and $40. Most auto parts shops will also carry a socket that is made for these units for an additional $10. Hope this helps someone!

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