STI990

I was racing this past weekend at waterford hills raceway and toward the end of the day I noticed that on startup it blew a puff of smoke, the car started to idle with some smoke from the exhaust. I went out for another run and the smoke started to fill the inside of the car and I could see it out the back. When I got back I noticed that the whole front of the motor and underside of the motor and car were covered in oil.

The car is running fine with no codes thrown.

I had it towed home, cleaned it up so I could start to investigate where the oil was coming from. After cleaning I let the car idle and couldn't see a leak from anywhere. I then went for a little drive and when I got back the oil was everywhere. I am almost positive that it is coming from the front Main seal... similar to this thread https://www.corvetteforum.com/forums...main-seal.html. I dont think it is leaking till there his more oil pressure/rpms.

Now some history: I replaced this seal and the harmonic balancer with a SLP and have not had any issues till now with this seal, but it is new. I also just started using 50wt at the track, could this create higher oil pressure and cause this to blow? I am seeing high oil temps and will be putting in a dewitts radiator/EOC when I do the front main.

Also I think the smoke on start up was due to the high RPMs and some oil getting into the intake, I looked in the throttle body and intake and found some oil, any recommendations on a catch can? I also replaced the PCV valve today.

I am looking for some advice on why this seal could have went again? I don't want to replace the seal and have it start leaking again.. Also is there a "better" front seal? And where do I get the thin piece of metal that is used if the crank has a groove? Any advice will help, thanks!

neutron82

does the slp balancer that you used have a square keyway?... if so and you have a stock crank obviously you can't use that keyway but if you don't seal it up with silicone it will leak... did you remove the cover the first time you replaced the seal/balancer?... if so it's also possible that you did not get the cover aligned properly thus causing the seal to wear out prematurely... an oem seal should work fine or felpro makes good gaskets/seals as well... is your car mainly a race car?... if it sees a lot of high rpm use and you want to prevent any oil being ingested back into the intake as well as preventing excess buildup of crankcase pressure you could run some lines off of your valve covers to a breather can and eliminate the pcv system

STI990

The balancer was for a stock crank, I have driven a good 5-10k miles after replacing the front main..but I also replaced the front cover seal etc.. Would front cover seal only leak at higher rpms?

STI990

This is what was installed: http://www.slponline.com/product/100225--LS1-LS6-LS2-LS3-Harmonic-Balancer-Underdrive-Pulley.html

Where would you add silicone?

neutron82

yeah man if you have a stock crank then you need to seal the keyway up on the balancer... there is no keyway cut in the stock crank so since you are unable to use the keyway that is cut into the balancer oil can leak out through that area... if you can get a wrench on your crank bolt and are able to get it loose and back it out far enough you might be able to seal the keyway up with silicone and not have to move the rack out of the way, just make sure to clean it up and that it is bone dry before you fill the slot with silicone

STI990

Wouldn't that have leaked from the start?

LoneStarFRC

No, but if it was not lined up/installed correctly, it will eventually leak. It may seal for a short period of time but WILL leak eventually if not installed correctly. Correct alignment of the front cover (and rear as well) is critical.

I would also not use 50W oil. If you just have to have a heavier weight, use a good 20W-40.

HTH

4DRUSH

Could be excessive crank case pressure. I suggest venting the crank case to atmosphere using a vented catch can with -12 hose to valve cover.

STI990

Any suggestions on a kit? Or what catch can?

neutron82

that's more of a custom setup... I had -10an bungs welded into each valve cover then run lines from those fitting to a jegs breather can (#52202) but you can use virtually any breather can, fittings, and hose of your choice

STI990

How does doing this compare to a watts or traditional catch can setup?

neutron82

with most of the catch cans on the market you are still utilizing very small diameter tubing which isn't near big enough to release excess crankcase pressure and it even corks down to a bottleneck at the pcv valve to make matters worse... and then you still have a chance of oil making it's way back into the intake which sucks... by eliminating the pcv system and running large diameter hose to an open can you are allowing the motor to breathe and avoid excess pressure buildup... the only drawback to this type of setup is that there is no longer any vacuum drawing out contaminants in the oil under normal driving conditions so you may need to change your oil more frequently... most of it is condensation and will burn off after extended drives at oil temps around 190+ or it will be pushed into the can when pressure builds up in the crankcase

4DRUSH

http://www.summitracing.com/parts/mor-85465/overview/

You can mount it on front of pass side inner fender (under headlight)

Install a -12 bung on oil fill cap or valve cover

Best to run hose so oil can gravity drain to the can

STI990

I see this forsale with covers in the for sale section, this what ur recommending? What would I do with existing pcv system, sorry if this is a stupid question..

4DRUSH

That's the idea, don't think it will be a true bolt-on mod on your car.

You can keep your current pvc, might have to unhook the vented system for state inspections?

STI990

I don't have state inspections. Why wouldn't it be bolt on? It comes with covers. So this method is more for venting?

STI990

You think this may explain front main leak as well.

4DRUSH

If the crank case builds pressurize, from blow by, the pressure needs to relieve somewhere, usually a crank seal
(which is more of a power adder motor problem)

The seal may not be ruined, vent the motor before replacing the seal

The pressurized air contains oil also, hence the reason for catch can to separate oil & air

Edit: First remove the oil fill cap & see if the motor is puffing smoke

.

STI990

I removed the cap and there is no smoke or vacuum, I also put a think piece of paper over it to see if it pulsates or spits up oil and nothing..

STI990

the seal still leaks at idle so I think whatever seal it is is shot, dont you think?