Rave TT

My car smokes (oil burning) from the left tail pipe, it is very bad at start up then ssems to burn out and not be that noticeable, does anyone have any idea what is causing this. tia.

Kevin

Rave;

You really have 2 choices.. Turbo might be failing which is NOT uncommon.. Do you let your turbo's cool down prior to shutting the car off? The other option is high oil level, which can be the case. You need to check and see if you have oil pooling under the turbo?

docjackson1

as far as letting your turbocharger cool down for a few minutes before you shut down, i would think that this is a practice followed by few owners. if i am not incorrect, i do not think that this practice is recommended in your handbook. from what i can understand, unless you have just raced your turbo on the track, a cool off period is not necessary. i would be interested in the comments of others who know more than i do.

Kevin

doc you are in denial.. Take it with some humor.. Where is the damage from running the car for 1-2 minutes.. If it's not in your makeup to run the car for 2 minutes, do what you can.. 98% of the cars manufactured with turbo's today have water-cooled bearing housings to protect the shaft and seals. Our turbo's don't have that option. They rely on oil cooling..

msw

Kevin,
Not doubting your knowledge, especially given my lack of it when it comes to turbos...but oil cooled to me means air cooled, which means the car should be moving. The only time my 97 turbo seems to run on the warm side is when I sit in traffic "idling."

To me it makes more sense (the last few minutes of driving) to "chill out." I have never "let my turbos" cool by sitting for a few minutes before shutting down. I have 139K miles on the car and it seems to have worked for me.

Kevin

Agreed, air is cooling your oil and oil is cooling and providing lubrication for every bearing in the engine and turbochargers. Infact you have oil squiters aimed at cooling your piston from the underside, wicking the heat out of rings and providing lube to the wrist pin. Your KKK turbochargers also, have an oil squirter port to cool the turbine side shaft and seal. 139K is at the tops for any stock turbocharger.. Normal watercooled turbo's typically fail between 100-120K

yeldogt

I have had many SAAB turbos over the years - I do not remember any that used water to cool the units . I do understand that many makes do at this time. I never had any fail and I never idled to cool them.

I remember many different ideas on 'turbo' life. I was told by a CE at Mobil that the main problem with oil cooled units was that you could cook the oil in the bearing. This was the main problem with early units using conventional oils.

It was my understanding that modern syn oils will not burn or gum up at any heat that a motor can normally produce.

I really do think that so much of this stuff is luck as to who has a failure and who does not

docjackson1

kevin, you may be right, but it doesn't make sense for porsche to give you a 4/50 warranty without warning you about idling the engine before ****ting down, if they were concerned about turbo failure.

msw

Aw Kevin...now you have gone and done it...if my turbo(s) break in the near future, you are going to have rebuild/replace them for me.

But...when I told a friend I was still on the original clutch at 80K miles, he laughed and said "any day now." Still going at 139K.

Rave TT

Forgot to mention, I have stage 4 upgrade.My mechanic said my Turbo seals were going, if not tended to, I would risk damaging the turbo fan blades and getting metal into the engine.

Kevin

So this is what your mechanic is warning you about? It's a bitch to clean out aluminum out of intercoolers...

dbf73

I had always assumed that when Porsche went water-cooled that the turbos would be water cooled as well. Has anyone actually done this? Pros/cons other than the obvious (complexity,cost)?

Dock

Maybe that's why Porsche put this in their owner's manual..."Do not stop engine immediately after hard or extended driving. Keep the engine running at increased idle for about two minutes to prevent excessive heat build-up before turning off engine."

I follow their advise, but at idle power versus increased idle.

Rave TT

Ouch!! That doesn't look good. Good thing I didn't ignore the smoke.

docjackson1

dock-i certainly can't fault you for being extra careful with your car. i own a twin engine turbo charged airplane, and with those air cooled engines, i need to run the engine at idle for 2 minutes after landing. i think porsche is telling you with normal use (not immediately off highway, track use, etc) you can just shut it off. most driving before you park it is probably low speed/rpm. but if you want to be extra careful, more power to you.