What's this Oil Leak?

[jcs44]

Hey LT4 gang,

The last time I changed my oil, I noticed it being a little wet under the front of the engine on that cross member. It wasn't much to speak of and I think I had the same thing on a 95 LT1. Is this maybe an ooze fron the front main seal or.....? Any ideas?

Thanks, JCS44
LT4 Vert, Blk/Blk
30,000 mi.

 

[Vettelt193]

I think you hit the nail on the head with the front main seal.


it could also be the intake manifold, but that is unlikely to drip up front.

 

[jcs44]

I also understand there's a crank angle sensor in that area that has an o-ring seal that can leak. Anyone familiar with that?

 

[wx briefer]

crank pickup oring can, indeed, be a problem. I replaced mine at 66k and now at 93k I have another leak at the front. I am hoping that it is, once again, the o-ring. The GM o-ring barely fills the hole. Hardly any friction at all upon sliding into the hole. (keep it clean, OK?) Anyhoo, I think I'll try to find a slightly larger piece of rubber (o lordy......) this next time around.

 

[Chetzki]

Crank Angle Sensor

I also understand there's a crank angle sensor in that area that has an o-ring seal that can leak. Anyone familiar with that?

Will someone please take a picture of the crank angle sensor so I know exactly what I'm looking at? I have a front engine oil leak as well. I suspect the front seal, but would like to rule this one out.

Thanks!
Chetzki

 

[PLRX]

JCS,

this is the main seal located on the timing chain cover...YES behind the fabulous Optic Spark Distributor. My first Vett had this leak and, I'm waiting for my new one to get it. I fixed/replaced it and it stopped. This is major surgery, be ready; If you are planning into replace the seal, my advice... replace the belt, Optic, cables and give the radiator a flush and, replace thermostat.
Do not forget the 24 pack of beer
-Pedro

 

[jcs44]

Hey Pedro,

That's a good run-down. I think since mine is only a small drip that never has reached the floor, I'm going to let the major work ride for a while and see what happens. I'm hoping it's just that CAS O-ring.

Thanks, John

 

[PLRX]

Anytime