whiteturbo

I almost forgot..............they never smoke unless someone is around to see it. Just make sure no one is watching and it will never smoke. I have had this to happen and i think everyone has from time to time.

Hawk2109

My tech brought up another possibility.

The oil / air separator may be due for replacement.

This is a common issue on the track. There is a upgrade that is PAG only but here is the part number for you. 996-107-926-00 This might be the issue too.

Happy to help, if indeed I have done so. LOL

Erik Johnson
GBox Sales Manager
(303) 440-8899 work
(303) 895-4828 cell

Macster

Was not aware the AOS a problem with the Turbo engine, but if the AOS can be a problem on the Turbo engine then the AOS needs to be eliminated as a possible source of the oil smoke.

I've not had my 03 long enough to get it into the miles at which based on my experience with my Boxster the AOS can go bad (80K and then again at 180K though some have reported AOS failure with fewer miles) and when they did go bad the smoking was not just at startup but all the time, as long as I was willing to let the engine run. I didn't let it run long either time though but shut it off and had car flat bedded to dealer to have AOS replaced.

Also, I believe it possible if these engines sit a while it is possible some of the oil to drain from the oil tank into the engine.

AFAIK there is no valve between the oil tank the oil pump and the oil can seep past the oil pump gears and slowly run into the engine.

Then upon engine start the engine can have more than its usual quart or two of oil in it and this can result in oil smoke upon startup.

Sincerely,

Macster.

brotherman

Erik, the car only has 25K miles and has never seen the track so I sure hope the AOS is built a little more resilient than that!

The car does sit quite a while in the garage (sometimes 2 weeks) since I'm gone a lot so that maybe the culprit.

Macster

25K miles a bit early for AOS to go bad but an AOS can fail at any time.

Given the potential for very serious engine damage, even destruction should an AOS go bad and the car driven at all, even the engine started just to idle it for some sort of diagnostics effort, I always advise that if the smoking persists for more than a moment or two, is accompanied by any other engine misbehavior such as exceptional and out of the ordinary rough idle, or when warm an idle that rises and falls a bit, hesitation from idle, excessive vacuum so much so that at least in the case of my Boxster with the engine idling I was unable to remove the oil filler tube cap (though not sure if the Turbo engine would manifest this same symptom in the event of a failing AOS), a sudden increase in oil consumption, to avoid running the engine and get the car to a qualified shop to eliminate the AOS if it can be eliminated and if not then replace it before attempting any other diagnosis.

Sincerely,

Macster.

Dock

That's got to be one of the longest sentences I've ever read.

wross996tt

LMAO...macster can't write anything less than a paragraph...LOL

Macster

Obviously my editor's on holiday.

Sincerely,

Macster.

Kevin

"AFAIK there is no valve between the oil tank the oil pump and the oil can seep past the oil pump gears and slowly run into the engine"

Macster that is a inaccurate statement. There certainly IS a valve between the sump tank and engine. It is bolted to the bottom of the engine case right under the sump tank. Located directly below number 6 cylinder. Infact this check valve has failed on early '01 engine causing oil starvation. This is a very rare situation.

Folk you guys can run over the 993TT forum and read the turbocharger oiling and smoking issues that the 993TT have had. Similar fate is in store for several 996TT owners that have purchased cars that were run hard and put away wet. If the SMOKE on start up happens every ignition cycle, you have issues with the turbine side sealing rings.

BTW, Rotella synthetic is a VERY good heavy duty engine oil. It has not been approved to run in a Porsche>I could be wrong. The Shell diesel synthetic is VERY good. There are "many" folks running the heavy duty synthetic oil. The formulations reduce ash and generally have higher additives for protect against "shear" Try and mail order in Mobil 5W50.. Think ahead for your oil changes.

Macster

Sorry, but I'm a bit denser than usual: Are you saying there is a valve in the oil feed line from the oil tank to the high pressure oil pump?

Or is there a valve in the oil line that runs from the low pressure (scavenge) oil pump to the oil tank?

I could accept a valve in the latter, as a one way check valve. The former though.... I am not a big fan of any valve between the line that feeds oil from the tank to the oil pump. But if it exists, it exists.

Sincerely,

Macster.

Macster

I can't take what I interpret as a recomendation by you to use an oil intended for use primarily in compression ignition engines (diesels) in spark ignition (gasoline) engines and specifically Porsche Turbo engines pass by without a comment, or two.

Shell Rotella is a good oil -- I used it in my VW TDi (turbo-charged direct injection diesel) engine, but it is not suited for gasoline (spark ignition) engines.

Ignoring the issues with converter damaging anti-wear additives, good diesel oils are very high detergent as they must be to deal with the very high levels of soot that diesel oils have to contend with.

For slower revving typically single overhead cam diesel engines that do not subject the oil to as much chance to foam, and for diesel engines which have superior de-foamers that are designed to remove as much air as possible from the oil before it is returned to the oil sump or tank, this is not a problem.

But for a higher revving dual overhead cam gas engines that not only introduce alot of air into the oil and which do not have as good de-foamers as diesel engines diesel oils are not really suited to use in gas engines.

My point is that diesel oils are *not* recognized by Porsche for use in its gasoline engines not only possibly for the presence of converter damaging anti-wear additives but because of the risk of over aerated oil that may subject the valve lifters even main and rod bearings to oil with to much air content to the point the oil's superior high temperature high pressure performance is severely compromised. Even if the oil doesn't cause any lubrication problems its performance as a hydraulic fluid that it fulfills in the zero-lash valve lifters and VarioCam hydraulics can be subpar.

In the lifters the air allows the lifter to collapse a bit and at lower engine speeds maybe after a high speed run engine maybe just all the time if the oil gets some miles and build up higher levels of contamination (which can make the oil more prone to foaming), lifter noise levels will be higher, at least until the aerated oil is slowly replaced by oil that is not aerated.

At high speeds noise is not an issue but the lifter's ability to follow the can lobe profile certainly can be an issue. Dyno testing has found aerated oil can and does have an effect on engine output.

I don't even want to think about the possible impact on the VarioCam hydraulics and VarioCam behavior.

Your recommendation re Mobil 1 5w-50 is spot on. I have on hand 12 quarts of Mobil 1 5w-50 and will be using this oil next oil/filter service, due to happen at 20K miles. The oil was just changed around the 17K mile point but I want to get back on my 5K mile oil/filter service interval and 20K is when it will happen.

My Turbo owners manual does advise giving the engine up to 2 minutes of running at idle after a hard or extended run. I do not always let the engine run 2 minutes before shutdown.

However, certainly after a hard run -- which I interpret as track usage -- I would give the engine 2 minutes to cool down even on top of whatever other cooldown running it received.

And usage my car gets subjected to very frequently -- every day, sometimes several times a day when I'm on a road trip -- is after an extended run at speed (like extended driving at highway/freeway speeds) I give the engine time to cool down or let the temperature gradients even out before shutting down.

This is done partially by low load easy driving as I make my way over surface streets to a gas station or my destination at any rate followed by a cool down time with the engine running at idle.

Sincerely,

Macster.

Kevin

Again, we have some mis-information. Oil is like religion, and girlfriends. I suggested that it was okay to run Rotella HD synthetic in his engine. Shell was the factory fill till 1994. There are many race teams around the world that still use Shell. Many Porsche engine builders are running Shell Rotella synthetic in there GT3's and newer water cooled engines.

The additive packages actually benifit the overhead cam engine. What do you have in the Detroit Series 60 engine. You have a overhead cam with lifter assy, and a electromechanical Jake system.

I prefer Mobil 1, I run Delvac in my Series 60 Detroit Diesel. I have used Mobil Diesel in Porsche engines. Aircooled and water cooled. Here is a brief Q & A from Mobil >> https://www.mobiloil.com/USA-English...n_Diesels.aspx

Again, I have made the recommendation for Mobil 1 5W50 now, and in the past for our engines. I also recommend Mobil Turbo Diesel where people cannot get 5W50. Shell Synthetic is also a VERY good oil It will NOT damage your engine. Neither the Shell or Mobil Diesel are on the Porsche approved list, but I wouldn't worry about either of these oils.

For air cooled Porsche turbo engines I do recommed Mobil VTwin. You can go to Mobil's website and view there opinion about this oil and the recommendations for it in the air-cooled Porsche.

Kevin

https://www.mobiloil.com/USA-English...sion_Cars.aspx

Mobil has a great Q & A page..

adam_

In-deed.

Everyone is aware of BITOG, right?

www.bobistheoilguy.com

Great forum, in particular some of the UOA threads- both on virgin oil and used.

There is no topic more discussed on every board. And I've come to the conclusion that the more you know, the less you post- you realize it is futile. The subject too broad, the differences hard to detect, the use conditions infinitely varied, and the marketing spin persistent.

A

wross996tt

I'm with A...I suppose if I were going to put outrageous miles on my cars, oil might play a role, but given the quality of oils we are mostly talking about, I doubt anyone can "prove", with data, there is any perceivable difference in the performance and or reliability of the lubricated parts of the system using any of the lubricating formulas in question.

How about that sentence Macster?