conde'strans

iTrader: (8)

So I decided to take the TA out to do some WOT tuning and on my first WOT run sh*t hit the fan! Car has a 408 with 11:1 compression if I remember correctly.

At approx 115 smoke started coming out of everywhere! Once pulled over, I realized the belt had come off and saw some oil leaking straight from under the flywheel. Come to think of it, I had just noticed two oil drops on there while hooking up the wideband(shoulda stopped there)! I then turned on the car and the car did have good oil pressure, no weird engine noises, so that was some relief.

Prior to this, I had noticed it was quite tough to simply remove the oil cap like it had vacuum sucking it in. It has a closed evap system so I am now wondering if I need to throw some breathers on there to reduce the pressure. What do you guys think? I'm putting it in the shop tomorrow to check it out but more than likely the rear main seal. Will breathers help? I already have a brand new oil cap breather lying around.

Majestic9C1

iTrader: (19)

sounds like the pressure blew the rear main out...

conde'strans

iTrader: (8)

Yep, just wondering how to prevent it from happening again! hence, the breathers question.

chrysler kid

iTrader: (14)

Oil pressure shouldn't blow the seal unless you overfilled the car with oil. More than likely the rear main was not installed correctly whenever your motor was built

fleetmgr

Your evap system has nothing to do with crankcase pressure, and too much crankcase pressure can indeed push oil out of the rear main seal, and the front seal as well. Do you still have a functional PCV system? If not, get it back on there pronto. It's sole purpose is to evacuate the crankcase, and keep the crankcase pressure negative, as it's supposed to be under all conditions.

conde'strans

iTrader: (8)

Sorry, that's what I meant to say, the pcv system! it is on there but i hooked it up as a closed system. I am now wondering about adding the oil cap breather to see if it helps prevent this from happening again.

nhra686

A vacuum pump is your best solution....

conde'strans

iTrader: (8)

So it ended up not being the rear main seal leaking! Already put the tranny back in, gonna remove the intake tomorrow to check out the oil sensor because the leak is coming from the top somewhere in that area.

Could it really be the sensor leaking like that all of sudden while at WOT???

Orange Juice

iTrader: (3)

I installed a GZ pump and still blew out a seal.

conde'strans

iTrader: (8)

if I install a breather oil cap on the passenger side and a breather in the rear driver side valve cover, will I still need the oil catch can? It does not have a ls6 valley cover, just a stock one.

conde'strans

iTrader: (8)

So it turns out it was the oil sensor where the leak was coming from! I'm still not sure what route to go with the pressure crankcase pressure issue.

1 FMF

iTrader: (1)

normally, your intake manifold vacuum sucks crankcase vapors thought the pcv valve... with pcv valve regulating and controlling suction when there's high manifold vacuum. because you're sucking the crankcase, you need to allow air back into the crankcase somewhere somehow otherwise you'll have too much crankcase vacuum and you'll end up sucking in the front and rear crank seals. normally one valve cover nipple has a hose going to your air lid to pull fresh air in which has been filtered by air filter. then if you get too much crankcase pressure under high rpm/load then it would flow out the valve cover nipple into hose going unrestricted to airlid and you should never have an excessive crankcase pressure problem.
if you need to measure crankcase pressure, easiest way is a piece of 1/4 or 3/8 hard enough hose that's hose clamped to dipstick tube (dipstick removed obviously) going to a pressure/vacuum gauge. if your not concerned about vacuum and hose collapsing then soft clear vinyl tube works well and is cheap, just don't let it touch anything hot. ideally you should always have 0 psi to -1 psi crankcase pressure (slightly negative) and not more than +1 psi under full load high rpm.