There are probably a million threads on this, but...I was told I have a rear main seal leak. I'm not getting any oil drips on the ground nor do I seem to losing a big amount of oil. The only leak I know of is at the oil fill tube, do you guys think that could be running down making it look like a rear main leak?
My other question is, the company that rebuilt my engine told me "The rear mains they use can't leak on the LT1. I think the guy is full of crap, but am I wrong?

 

Yea he is full of crap.

And yes it is possible that it could be rolling down from the dipstick tube. Its also just as likely though that it is leaking from the back of your intake manifold down along the back of the block and looking like a leak. Im sure the garage didnt take much attention to it inless you took it in for the leak. If its just something we notice, we generalize where the leak is ( Front Back, etc. ) and let the customer no. No need to poke and prod around if they dont want it fixed.

 

Well I know it's not the intake, it's bone dry back there. This really makes me angry, this will be the 3rd time it's gone back for oil leaks. I figured he was full of it.

 

Just deal with the little leaks. I have not been able to get either of my LT1's to stop an occasional drip.

 

The reason he said the rear main won't leak is most likely b/c it is a one piece but like everyone knows it is very possible...
Check the bolt the holds the dipstick tube in... should be 10mm also i would check make sure that the tube is a little tight going in so it seals.

 

Where are you seeing the oil on the back of the motor? Is it on the block, the pan, dripping down onto the transmission?

 

Sorry guys when I said oil fill tube i ment the one where you put the oil in on the passenger valve cover. Myself I don't see any oil, only oil sitting on the valvle cover from the filler cap leak. It makes it really hard to look underneath the car for leaks because this car had major oil leaks in the past that the previous owner ignored and just drove. So the underbody is unfortnatly a greasy mess. So who knows whats old and whats new oil. I'm going to try and hose some of it off tomorrow with some degreaser.

 

I suggest you change to a high mileage like valvoline max life and then wait a few days of driving and then add an IR die to the oil. Then if you still see drips start looking with an IR flashlight.

I do not recommend washing any LT1

 

Well I was just thiking about washing the underbody. I'll probably just take it back in, I shouldn't have to run high milage oil in a motor with less than 5k on it. Thanks for the help though. Any idea where you get that die? I work at autozone and I know we don't have it.

 

Agreed, but then you shouldn't have a leak if you only have 5K miles either??????

Perhaps you don't understand what "high mileage" oil can do. It has more of an additive to help swell up rubber type seals and can often seal up a leak that otherwise would need replacing. If it can help so you needn't go into it, it's worth a try. Don't let the term "high mileage" throw you.

Napa carries die and usually any Snap-on dealer carries it on the truck.