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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: pedigo78 on July 21, 2013, 11:30:11 pm

Title: oil leak????
Post by: pedigo78 on July 21, 2013, 11:30:11 pm
Ok, guys I have had an oil leak for awhile now, and I have replaced everything I thought it could be. New oil pan gasket, all torque down, everything is good and tight. I have wiped it down and laid under it with it running, but nothing drips. When I get in and drive it then look under I have oil all over, looks like it is dripping down the rear of the motor hitting the flex plate and going everywhere. I question is would it take that long for it to leak from the rear main. and the other issue is. the motor is just rebuilt so the seal is pretty new. either way I am sick of it leaking and  need to fix it.
Title: Re: oil leak????
Post by: rich weyand on July 21, 2013, 11:58:18 pm
The source will be the furthest forward point that is wet.  Once oil gets loose while you're driving, it'll go everywhere, so the wettest spot isn't it, the furthest forward is.  One question: is your power steering pump dry on the bottom?
Title: Re: oil leak????
Post by: PrchJrkr on July 22, 2013, 09:11:16 am
First of all, thank you for your service to our country.

I had the same issue with a 2.8 Jimmy I once owned. It was driving me crazy. In the end, it turned out to be the dizzy seal. Good luck.
Title: Re: oil leak????
Post by: zieg85 on July 22, 2013, 09:15:12 am
It it were me, I would concentrate my efforts around the rear of the intake be it the intake itself, distributor gasket or even a bad oil sending unit switch.
Title: Re: oil leak????
Post by: gildardo01 on July 22, 2013, 10:06:39 am
i also think it could be somewhere around the rear of the intake... maybe they used the rubber seals in the back of the intake instead of a bead of silicone..... thats always a problem
Title: Re: oil leak????
Post by: pedigo78 on July 22, 2013, 12:37:09 pm
thanks guys, ill check all those points. on my day off.
Title: Re: oil leak????
Post by: blazing816 on July 22, 2013, 02:24:09 pm
This may be extreme, when I first bought my truck it would never leak oil I could see but was using a lot (and it wasn't burning) and it turn out that someone ruined the dip stick seal and it only sprays out when there I pressure of the engine move it.
Title: Re: oil leak????
Post by: pedigo78 on July 22, 2013, 10:18:33 pm
I thought that too, so I pulled it and put a little pookie around it. But maybe I did a shotty jobs, ill just have to get under it this weekend
Title: Re: oil leak????
Post by: pholliday1 on July 24, 2013, 11:45:12 am
Zeig is probably right on the money, the oil pressure switch and related pipe fitting's associated with it can be a culprit. As pressure grows it can easily weep around a loose fitting. Sometimes the only way to access the problem is to pull the air cleaner and "climb" under the hood with flashlight in hand to get to the problem area and yes you need to have the motor running to properly check the "rear top end" of the motor...just be careful..
Title: Re: oil leak????
Post by: Irish_Alley on July 24, 2013, 02:06:40 pm
I changed my intake gasket a couple times trying to fix a oil leak then come to find out the first time I pinched the oil pressure hose and cracked it a little.
Title: Re: oil leak????
Post by: pholliday1 on July 25, 2013, 02:21:00 pm
You may have tie or hold out of the way the wiring harness that goes behind the motor. Most likely you'll discover your leak from the topside good luck Siemper FI  Devil Dog!
Title: Re: oil leak????
Post by: sbx22 on July 26, 2013, 01:57:45 am
I had this problem too with my rebuilt crate motor. There was oil all over the oil pan, flex plate, and starter. It turned out to be a bad rear main seal. I tried to get the shop to repair it, but those suckas ignored me. So I replaced it myself and has been good since. I hope yours is an easier fix. The 2 piece rear main replacement is doable, but just a hassle.
Title: Re: oil leak????
Post by: Fairlane514 on July 26, 2013, 09:02:50 am
Another possible leak can be the flex plate/flywheel bolt holes in the end of the crankshaft. If the holes go all the way through, its possible for oil to travel around the threads and leak past the bolt heads and appear to be a rear main seal leak.

Just be sure to use loc-tite on the bolts to seal the threads.
Title: Re: oil leak????
Post by: pedigo78 on July 26, 2013, 06:10:56 pm
Alright well I found the problem. started it, laid under it and after it got warmed up I saw the oil seeping from the pan and following down the seem of the pan to the rear. This is a good thing cause its just a gasket. although it is a pain, cause I just changed it with a one piece gasket. Guess this time ill replace it and add more pookie to it.
Title: Re: oil leak????
Post by: rich weyand on July 26, 2013, 06:22:18 pm
Excellent!  Thanks for letting us know.