Quadcammer

Ok wtf.

99 2.5, 109k miles
2qt deep sump
New aos
997 return pipes
Nt01s
Blue group for de

The bloody car smokes after a few minutes on track. i run the oil level low, the aos is a brand new porsche part, and i even added a catch can to deal with any oil the aos cant handle, but it seems like it smokes almost every session and i mean badly. smokes worse after braking hard for a turn, downshifting and then getting on the power. never smokes on the street, motor sounds fine and runs ok so i dont think its a motor issue, but im at my wits end.

Any help would be greatly appreciated. its a fantastic car on the track otherwise but id really like to put this smoking crap behind me before watkins glen in july


Thanks

Marvinta

have you tried a nicotine patch?

Quadcammer

Clever, but that didnt work either

968workaholic

Are the scavenge pumps on the heads installed correctly? Can't hurt to change the valve on the driver's side head that the crossover pipe connects to

HoBoJoe

If you're at your wits end maybe it's time to take it to a pro, shoot me a PM if you'd like a suggestion or 2.

Marvinta

He he, sorry couldn't resist. Did you look at the spark plug tubes?

mjj0000

My first thought too was the scavenge pumps. It is possible to overwhelm the AOS without it having failed and this could be happening on hard stops and cornering, but not when driving on the street.

I'm also curious where you would attach the catch can to. Seems like such a thing would mess with the crankcase ventilation.

Quadcammer

Scavenge pumps are where I'm now focusing.

Plan of attack is this:

Replace AOS with another new OEM one under warranty
replace the PCV valve with new OEM
Remove and inspect scavenge pumps for damage, improper orientation, etc.

The catch can is inline with the J-Tube. Its not vented to the atmosphere so it should not effect crankcase ventilation.

Quadcammer

here are the pics of the pump. On the last one, the pointer shows the 1-3 mark for internal orientation, which appears correct to me.









Any ideas on how to test for an obstruction in the head to the crank drains? Compressed air?

Thanks.

968workaholic

Which side was that on? The pumps are concentric, meaning they can go on either side. It all depends on which way they are pointing. The drains from the head to the crankcase are large, it would take a big piece of something to block them up

Quadcammer

that was the passenger side (1-3).

Thanks for the input on the drain hole input.

968workaholic

I would think 4-6 would be more suspect, since that one is on the front of the motor and you are having issues after hard braking. Hope you find it

mjj0000

Are there photos prior to the pumps being removed? It is easy for an inexperienced person to get them installed incorrectly. A photo would help to confirm (or deny) if this might be the problem.

Quadcammer

They were installed properly with 1-3 facing the crank on the passenger side and 4-6 facing the crank on the drivers side.

My guess is that on the passenger side, under hard braking, all the oil in the head sloshes away from the pump, and then when you get back on the gas, all the oil rushes back to the pump and it can't keep up.

Also, the AOS is on the passenger side. The only way oil gets from the drivers side to the passenger side AOS seems to be through the pcv valve elbow, which I'm also replacing.

Either way, I cleaned the pumps and reassembled them. Didn't find anything there that really seemed to be an issue.

turbochad

All of the badly smoking SPBs I have seen have either had a cracked ring land or cracked piston, a result of hydrolock from overfilled or bad AOS. Have you performed a leak down on the motor?