grcdvm

Significant smoke on start up, 80% driver side, goes away after 3-4mins, only on cold start. Correct oil filters properly tighten, turbo's appear healthy. Is oil scavanger pump likely culprit? Porsche tech says unlikely. feels its normal or possibly small amount of oil collecting in cylinders after sitting a while.

Careener

How long have you had the problem" See the recent link "Turbo Seal Problem?"

grcdvm

Problem has been getting worse over past 6 weeks, Minnesota car hence, it has an off season similar to the Minnesota Twins. Turbos were inspected by technician and he does not feel the problem rest there.

Kevin

As are 993TT age with miles, the turbine side piston rings take a beating from most of our driving habits. The turbine wheels are blued, the heat generated from the turbine housing wick through the turbo. As the turbo seals fail, you will have oil collecting inside of the turbine housing when the car is shut off. It is a matter of time, when you will see oil pushed out the compressor side. The scavenge pump is very good and capable of handling the oil requirements.

Jeff 993TT

This might help: http://www.993faq.com/archives/cat_engine.html#000310

Depending on how many miles you have on your car, your turbos may actually be shot. But in my case, the above link fixed up my car just fine. Has also worked for about 10 other TT owners that I know.

It's a good place to start, and if that doens't work, then there are other steps ( ie turbo replacement ) to move on to.

grcdvm

Since faulty turbos were the consenses of most as the cause of my smoking 993tt. Today I replaced my K16's with new K 24 GT2 turbos. Guess what the smoke is worse!!! Now the journey continues to a possible scavanger pump failure, or ring or valve guide problem. I need advise before we tear this engine apart..What is the most likely, and what should be our diagnostic plan.. Tuesday is schedule includes a leak down test.

Jeff 993TT

Did you read the link I posted above?

grcdvm

Jeff; Thanks for the reference article. We have done EVERY item on that list, and have replaced and re-torqued the oil filters three times. Mobil 1 is the oil, and the level has never seen the top half of the dip stick.

grcdvm

Results of leak down test were 2-3% for all cylinders, great news. Scavanger pump checked out with flying colors. Car smoke on start up still capable of misquito control. Last ditch effort; special Andial 993 oil lines from scavanger pump to turbos installed. INSTANT solution. NO MORE SMOKE!!! The unique angulation change of these lines evidently prevent excess oil from entering the low position of the turbos on some of these cars as they sit.
I really like my new K-24 GT2 turbos. I noticed SIGNIFICANT power gain with little turbo lag. I think Evolution's billet valves are a excellent combination, along with the 5 bar fuel pressure valve, and Protomotive's ECU upgrade.

mjims

grcdvm

I have also just replaced my Turbos with new ones including all oil feed and return pipes etc, thats fresh mobil one (15w50) and new filters also. (carefully not overfilled) and YES IT IS WORSE.... MORE SMOKE!


How embarassing this is.....

As this is a prolific problem with (I bet) nearly every member of this forum.


Can you please give some more information on the Andial Solution you have done.

I'm am sure we are all very interested if there is a 'real' solution to this ever increasing fault.

Thanks

Jim Swift
PS/ Mosquitos are optional

Jeff 993TT

Andial's web page is here: http://www.andial.com

mjims

Thanks Jeff,

I suppose that would be the obvious answer!

Looking at the website, they are not the pipe's I was expecting to see?

I thought that it would be the small steel braided pipes that fit ontop of the Turbo Housing.

Am I thinking back to front?

Jeff 993TT

These are the ones that are on their web site:



$294.99

Funny thing about this whole smoking issue is that some people are "plagued" with it and some people never get it or get it so infrequently, that it isn't an issue. I think the jury is still out on the real cause. Or perhaps there are too many different variables which would affect this.

The andial fix has to use rigid lines. Becuase they are trying to raise the oil equilibrium point to a different level. Flexible lines obviously would not work, unless you tied them back or something.

mjims

I hear what you saying about some do and some dont.

As my turbo's were definately shot, I replaced them with some brand-spanking new porsche ones, & replaced all the oil lines just in case.

And the funny thing is, it's now worse

So I suppose it could be attributed to cleaner oil lines allowing more oil through, hense more feedback and more smoke.??

The pipes you show from the andial website look adentical to the solid rear pipes that connect from the Turbo sumps across to the middle of the block under the cam chain covers. The standard pipes are solid too.

If these pipes have 'non-return' valves in them where are they?

Jeff 993TT

From my understanding, their initial version had check valves to keep the oil only flowing 1 way. This current design just has bends in the pipes that are enought to keep the oil from flowing the wrong direction at rest. This has the benefit of not affecting the performacne of the oil lines when the engine is running.

However, seems like the bends could only be very slight, since there is probably not a lot of room to work down there. Which means that there's a very fine threshold between being bent enough to keep the oil from flowing back.

So other factors, such as parking on different angles may affect this as well.

You wouldn't happen to have a pic of the return oil lines before you installed your?? It would be very intresting to compare..