Hey guys

I am a newby to this forum so go easy on me

My 403ci has about 3000 miles on it now and has had a leak from somewhere in the front and even on a hoist its hard to tell where the leak is comming from. It is either behind the engine damper of the pan. I did use my old LS6 oil pan on the new LS2 motor. The motor was fully assembled minus the oil pan by a professional. Just wondering if there are any common places these motors leak from as it doesn't look like its comming from the timing cover but it coats from below the balncer and back towards the rear of the car. It will not leak when the car is not moving from what I have deterimend. Just odd that I have clean the mess up took it for a drive and can't really tell exactly where its comming from ???

thanks for any help

Drew

Here is a pic of my leaker

Its a 403ci with a Vortech Ysi and Meth Ijected.

 

here is a pic of the leak

 

If you didn't use some silicone for the oil pan where the timing cover meets the block they leak there sometimes.

 

thanks ZeekRacing !

 

By any chance is this fixable without pulling the cradle out from underneather the car? Will it seal if I just use some "right stuff" silicone on the outer side of that area?

its a 2001 Z06

let me know

 

You probably won't ever get it to stop leaking until you get the motor out so you can clean the area good. Just cleaning the outside and putting some silicone on it probably won't help. There is always the chance that the engine builder didn't get the front cover centered when it was installed. If it's not centered, it will leak around the seal.

 

You can give my suggestion a try. It's already leaking and if you didn't put the sealer in the front cover corners that is where the problem is most likely. I don't think you'll be any worse of if it doesn't work. The proper way to fix it would be to drop the oil pan and seal it at both the front and rear corners as suggested above as per GM's instructions and re-torque it to their spec with a new oil pan gasket in place. But that is a big job involving removing the cradle. I don't think you'll have to take the motor out to seal it up but I also don't think you'll seal it up from the outside eihter.
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You will have to devise some way of holding the motor up while you drop the cradle to the end of the cradle mounting bolts.
I propose dropping the cradle as far as you can on the 4 cradle mounting bolts. You may also have to remove the 8 bolts out of the upper a-frames. If you take these off there are washers underneath. Make sure they go back in the same place. I just put the bolts and the washers on them back into the mounting holes after the a-frames are out of the way. This should give you enough clearance to drop the pan about an inch.
This is from my manual:
All gasket surfaces should be free of oil or other foreign material during assembly.
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The alignment of the structural oil pan is critical. The rear bolt hole locations of the oil pan provide mounting points for the flywheel housing cover. To insure the rigidity of the powertrain and correct transmision alignment, it is important that that the rear of the block and the rear of the oil pan are flush or even. The rear of the oil pan must NEVER protrude beyond the engine block.
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Since the flywheel housing cover (bell housing) is already installed when you put the pan back up make sure it is back up against the housing when you torque it down.
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After you have cleaned the block and gasket mating surfaces Then put a bead of red RTV about .25" by .75" long on front corners of the block from the corner towards the center. Then put the same bead on the tabs of the front cover gasket that protrude into the oil pan surface.
On the rear put the same beads at the rear corners and onto the rear cover gasket tabs that protrude into the oil pan surface.
Tighten the oil pan-to-block and oil pan-to front cover bolts to 18lb/ft
Tighten the oil pan-to-rear cover bolts to 106 lb/in.
Tighten the flywheel housing bolts to 37 lb/ft.
Tighten the cradle mounting bolts to 81 lb/ft.
re-install the upper a-arms and bolts with the washers they way they were. Be careful not to cross-thread these. It's easy to do because of the lateral movement the arms want to put on the bushings.
Tighten the upper a-Frame bolts to 48 lb/ft.
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You may want to wait 24hrs for the RTV to cure. It's a lot of work but it may stop the leak.

 

thanks very much for all your input guys ! Its much appreciated !