I’m about to cry. I started chasing a bad main seal leak and found a bad oil pump and a deeply scored harmonic balancer. I installed a new front cover/oil pump with a new main seal and a new harmonic balancer. The main seal is still leaking. Much more slowly, but still leaking.

The harmonic balancer surface was perfect so nudging the seal doesn’t seem like it would do anything. I can think of a few options but I’d love to hear opinions:

1. try tapping the seal in a bit
2. replace the already brand new main seal
3. just let it leak

Let’s vote!

Thanks,

— Jason

 

I would start with a new seal. I think they can be bad or damaged easily. I ended up using two in my installation due to damage to the first one. From there I went the speedsleev route with my balancer having scoring. No leaks after that. You could add that to the new balancer if all else fails. It's easy and not too much money.

 

Make sure PCV path is not clogged up. Lots of happy forum posters like Extinct's PCV mod, helps prevent back pressure in the crankcase. Back pressure causes leaks to be worse. How are your valve cover gaskets?

Maybe add something like Bardahl or Lucas or STP thick gooey stuff, but that can plug up the tiny passages in the lifters if too much.

My mechanic gauges leaks in three levels: Minor, don't worry about it; Mid level, should be fixed when you can; Severe, needs to be fixed right away. Just don't let the oil catch fire!

 

Thanks for the replies. I had already replaced the PCV valve and checked it and it was ok. Valve cover gaskets have less than 5k miles on them.

I just tried a new seal and the leak is stil there but very slow. I have a sleeve but I haven’t decided if I want to try it or return it and live with the leak. It’s pissing me off to have to put a sleeve on a brand new $650 harmonic balancer!

— Jason

 

You mean the front seal? Could be a defect seal or too much scoring on the HB shaft. I had both problems on different engines:

• defect seal was installed already in a brand new front cover -> genuine seal fixed the leak
• slight scoring on the HB shaft -> new HB fixed the leak

 

Leaking betweeen seal and HB, or between seal and front cover? I like to put a thin coat of silicone on the od of the seal to seal it to front cover. As long as surface is smooth seal should not leak. I would doublecheck crancase pressure. There is no liquid oil at the HB level, it is all vapor and splash, so the only way you should have a leak is pressure in the crankcase. Stretch a latex glove over the oil filler tube with the engine running and make sure there is slight suction.

 

OK, I don’t want to jinx it, but a genuine ERR-6490G seems to have done the trick. No leak after 20 minutes of driving. FWIW, this one was brown and was pre-lubed, like it says in the RAVE. The regular ERR-6490’s were black and NOT pre-lubed.

Crossing fingers!

— Jason

 

The black seal that came preinstalled with my new front cover was wider than the genuine one. That's why I had that leak too.