New rebuild engine -heavy oil drip help!!


Active Member
May 25, 2001
I put the first 25 miles on a new rebuild today . I have a HEAVY oil drip on the PS in front of the starter area . It looks like it's coming off of the side of the block some where . There are dops that are just hanging under the frost plug closes to the front of the car and also drops on the starter shield . Any ideas where this oil is coming from thanks .
oil sensor looks dry . would a valve cover leak that bad ? I installed new GM gaskets and spray tacked them with cooper RTV . maybe I should of ran a bead of RTV instead ????
I'd bet the primary source of your leak is the valve cover...perhaps the one side of the gasket slipped 'in' as you installed it?! The oil on the crossover and trans TC cover is USUALLY from the rear main seal, although a gusher from the valve cover could get blown back to this area, or even the rear intake manifold seal could be the cause. Pretty tough to tell over the internet, but I bet tomorrows daylight will help you determine the source. Good Luck.
here's the update . changed valve cover gasket on PS . I also replaced the o-ring on oil cooler adapter as well . STILL LEAKING !!! what a PIA .
I had a similar problem. It was the turbo oil feed line connection to the block.
Did you put the rear main in or know how it is put in? This is a very common problem on rebuilds and the usual source will be the lack of silicon between the base of the cap and the block or possibly improper installation of the side seals. Some folks say it's taboo to put silicon here, but it's right in the GM service manual for the 3.8.

My personal belief is under boost conditions everyone pressurizes the crank case to some degree depending on general engine condition, ring wear, etc. Without sealant between the base of the cap and the block, oil WILL find its way out here and eventually wind up in the dust cover. Torque converter rotational turbulance will push the oil out the starter hole in the dust cover and get it absolutely everywhere, including drips on the cross-over.

May be coming from somewhere else, but this is a best guess if all connections are correct including the turbo drain to the block. I also use only permatex ultra black rtv in place of the side seals. Its more trouble but guaranteed success if done right.

Might also check rear of intake. If block at the rear is dry, the very likely source is the rear main.

Good luck. I hate oil leaks and these cars will get on your last nerve chasing them.