coreylt1

i fired up my motor and i have a pretty serious oil leak, it almost looks like its coming from between the block and bellhousing above the oil filter. what oil plugs are in the area that could possibly be missing?? im lost. could it possibly be the rear main seal? its not the oil pressure sensor

please help me asap!! need this car on the road soon!

Injuneer

Did you check the driver's side valve cover gasket? Did you check the pipe plug in the block right above the oil filter where the earlier year LT1's had the oil pressure sensor? Did you check the oil filter adapter to make sure it's tight? Did you check the oil filter gasket? Did you check the space between the back wall of the block and the intake manifold, that is sealed with RTV?

Probably a couple more possibilites, but that should get you started.

coreylt1

yes yes yes, checked everything. i found it, on the top of the block , a few inches to the right of the oil pressure sensor there is another hole(not sure what its for) it is plugged, and i guess the plug is just leaking. got a mirror and had someone crank the motor and watched it fill up and run all down the side of my block

the hole that is half covered by the head

jloshotz

I think that is where the check ball is, I read about it in a rebuild book on the LT1. Not sure why it would leak though....

Dave89IROC

That's a hole where the oil passage was drilled, it sucks when it leaks, but yeah, head has to come off, its a threaded plug

coreylt1

what caused it to leak? its a fresh rebuild, all new plugs and what can i do to prevent it from ever happening again?

cnorton

Usually, it leaks if it wasn't sealed and/or tightened.

Or, I recall once having a similar problem with a 1/4" pipe plug that had a .030" hole drilled through the center. I didn't notice the hole, put it in that same spot under the head, torqued the head and found the leak when I primed the motor. It was supposed to go in an oil galley front of the motor behind the timing chain to spray oil on the chain during operation. I don't even know when that kind of plug was put into production motors but if it gets installed in another spot in the car, it's an instant problem.

coreylt1

that's probably the problem here.. thanks so much

is it a dumb idea to reuse the head gasket and head bolts? engine was only ran for about 5 seconds and coolant didnt even get a chance to reach the heads yet

Dave89IROC

Get a new gasket, reuse the bolts

coreylt1

problem found. the engine builder that did the bottom end messed up, and im stuck fixing it. lovely at least i found the problem ! thanks guys

klrz28

That sucks. My buddy's rebuild is doing the exact same thing the hole is half covered spraying oil. We went to start it and it was spewing all over the place. Found that half a hole spewing. That blows the head and intake have to come off to fix it. And this was an engine builders fault. Exactly why we should of rebuilt it our self.. Why did Gm put a galley plug in such a stupid spot?

cnorton

That part of the galley serves no purpose but it has to be drilled there so that it connects two passages lower in the block. No one has, to the best of my knowledge, devised a way to drill a hole with two blind ends. The solution is to drill the hole where it has to be, plug the end, and let the unwary end user find out the hard way. You'll know to mention it next time.

Was the problem that the plug was left out, simply not tightened, or was it a drilled plug?

klrz28

The plug was left out