FELKER

The Right turbo and ducting was covered with oil.. thus the Smoke from the left tail pipe.

New Turbo, hoses, clamps and gaskets ordered.

Question: What items need to be checked for damage from the oil? Boost sensors? spark plugs.

Steve Weiner-Rennsport Systems

Hi John:

You did not say how many miles are on your TT but I would not be surprised if the other side turbo followed suit.

There are no boost sensors (besides the guage sender), per se, but I would clean out the intercooler. You might change the plugs if it was really smoking for awhile.

KKK has experienced some QC issues and I would recommend that your old turbocharger is rebuilt, rather than a new one,...

People like Kevin Matwitchuk do a better-than-new rebuild.

Joe S

John, my car is currently in for the same problem, although I've intermittently had the smoke coming from one or both pipes. Interestingly, this happened for the first time just recently shortly after I picked the car up from the Porsche dealer after it was in--and surely sat motionless for most of--more than a month for a color change. My car has 13,000 miles. My independent specialist tells me he has seen this a million times and, in most instances, it has more to do with the oil filter and associated stop valve than the turbos. I'll be picking my car up in a day or so (two day job to change filter and oil, clean out intercooler, etc.) and we'll see how it works, but I'd be hesitant to just throw new turbos on it at this point. I may be wrong (Steve?), but I do not think that oil getting past the seals when the car is not running is necessarily an indication that you need new turbos right now (maybe an early indication that wear has begun)--I'd be more worried about stopping the oil flow to the turbos when the car is not running (i.e. addressing the oil filoter/stop valve issue). Does your car smoke when its running (other than just until the accumulation bunrs off)? Also, I think Steve is spot on when he says a quality rebuild would be far better than new turbos--these things should not have seals failing at such low mileage in treh first place, so the problem must be at KKK and a new one might have the same issues.

Jeff 993TT

Felker, I am assuming that you already pursued the oil filter tightness issue???

Another test to see if the turbos are indeed bad ( as covered in the archives ) is to drain both turbos and compare the amount of oil in each.

I hope that your turbos were covered under your warranty!

Jeff

Bill S.

Comparing the oil in both turbo reservoirs does not necessarily indicate a bad turbo. My engine oil filter was bad. This caused the left turbo to fill with oil (a new turbo), but not the right. When the oil filter was replaced, the car no longer smoked.

When the stop valve in the engine oil filter is defective, the oil seeps from the large engine oil tank, through the engine, and into the pipes on the back of the turbo reservoirs. The reservoirs then fill-up. After some time, depending on the tolerance of your turbo bushings, the turbo housing will also fill with oil, causing the smoke. In my opinion, a turbo should ONLY be replaced when it's noisy or is smoking with a known good engine oil filter.

Some oil in the intercooler is also normal when the turbo bushings are within tolerance. In my experience, the turbos should last over 60K street driven miles.

Note that some cars will smoke for a few seconds after start-up. This occurs from oil being siphoned from the TOP turbo oil feed line. This is usually not a big deal. However, if you want to stop this too, Ruf sells oil stops valves for the top of the turbos.

Note that the 996 turbos also smoke for a few seconds after startup. This occurs even when Porsche added a loop to the rear turbo feed lines AND a special stop valve from the big oil tank to the engine (no stop valve was added to the top of the turbo).

Finally, some shops add the 996 TT special stop valve to the 993 TT. This stops the oil seepage even if you have a bad oil filter.

My 993 TT smoked even after the Ruf Turbo R conversion with re-built turbos. A new engine oil filter (revision #2) solved the problem. I'm not sure how reliable the new revisions are (#3 and newer) since my car smoked with revision #3.

Kevin

Information for all;

As I have posted in the past there is a sealing ring issue with the K16 & K24 turbochargers. I can further the discussion if you guys want to hear the details. Yes, the oil filter can be a problem, however once that is ruled out, most likely the turbochargers are failing. I can post pictures of the guts to show you what is wrong and why the parts are failing. For a long term cure, even with a brand new turbocharger, the sealing rings need to be addressed. The cure is to install oversized rings and hand file them to the bearing bore.

FELKER

Just tutrned over 55,000 miles.. had 45K when I bought it in Dec 2001.

The repair is under the 1yr Certified Porsche Warranty so I am just letting the dealer call the shots on the repair, since all they do is under warranty. can I demand a rebuild under warranty?

the oil filter issuse was not specificaly address, but the car will have an oil change/60K service soon.

I will have them clean out the Turbocharger..

HOW CAN I TELL if the other one is failing?