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-   -   Porsche c4s 991.2 start up engine smoke with Video (https://rennlist.com/forums/991/1149502-porsche-c4s-991-2-start-up-engine-smoke-with-video.html)

Rapter 06-25-2019 10:01 PM

Porsche c4s 991.2 start up engine smoke with Video
 
9 Attachment(s)
Hi everyone,

SYMPTOM : lots of engine smoke at start up
FREQUENCY : every start up

story:

last week i notice my oil gauge suddenly drop from 45%-50% full to the minimum level. I added 250 ml of oil and the level went back up to about 45%. The next day the engine started smoking as per the video attached, smoke smells like oil.

Attended the dealer and and they filled the oil level right up to the top 90%+, drove around for about 45mins and stopped at office for 2.0 hours. Upon start up, lots of engine smoke and the oil level fell to min level again.

No oil staining or external oil leak visible.

Slight delay on throttle compared to normal driving driving otherwise car runs fine...other than start up smoke

Preliminary dealership visit summary:
1. Damaged air oil separator
2. Leaking turbos (oil seals) - apparently documented in early production car (my car built 12/2016)

the car goes back in tomorrow.

Anything helpful i can suggest to the dealer dealer that others have experienced would be appreciated. I have full confidence in my dealership, their technical knowledge and customer service is awesome. I want to help them help me best.

update - June 28th 2019 - the dealer was unable to find anything wrong and there was no longer any smoke at start up. They added another .6L of oil to bring the car back to 50% reserve oil and returned the car to me. In speaking with the shop foreman, his opinion was that I did something wrong when I added oil but he was not able to indemnify what “wrong action” I did.

A question to you all, the only thing I can think of is that the car was on a slight driveway incline when I added 200ml of oil. Can you add oil if the nose of the car is tipped down slightly?


First repair conclusion
2019 conclusion: both turbos were deemed to be replaced by Porsche which has resolved the engine start up smoke issue.

Repeat symptom
Update October 9th 2020 : after a relatively uneventful summer driving season and some DE days the engine smoke at start up has once again. Since the re-appearance of the smoking at start up...in a only 1 afternoon however the car consumed the entire oil reserve and is asking for oil to be added... which to me leads me to believe the internal leak this time around is more substantial. The car is booked back in for re-diagnosis almost 11 months since the turbos were replaced.

Have any other cars been experiencing this? I have reposted another video.... but it is the same issue as before.


second repair
  1. revised air oil separator installed with nee check valves
  2. revised part no. Porsche oil lines and integrated check valves installed.
engine start up smoke resolved following second repair.

subshooter 06-25-2019 10:14 PM

How long do you park the car between drives? Do you park on hills or any angles?

Rapter 06-25-2019 10:24 PM


Originally Posted by subshooter
How long do you park the car between drives? Do you park on hills or any angles?

Car is parked overnight, 2 hours at work, 45 mins at meeting, 2 hours at work again and then overnight.

Parked with engine facing uphill, downhill and flat. Smokes in all orientations.

This car is my daily driver.

BSO 06-25-2019 11:40 PM

Sorry for your aggro.

Did you try to smell the smoke, burning oil exhaust has a distinctive smell, may confirm what you already know. If you're losing oil, it's going somewhere.

Mine smokes at times but it's moisture, most visible during cold weather, goes away quickly.

Good luck.

Rapter 06-26-2019 07:54 AM


Originally Posted by BSO (Post 15933262)
Sorry for your aggro.

Did you try to smell the smoke, burning oil exhaust has a distinctive smell, may confirm what you already know. If you're losing oil, it's going somewhere.

Mine smokes at times but it's moisture, most visible during cold weather, goes away quickly.

Good luck.

Smells like burning oil...

worf928 06-26-2019 10:00 AM

yep. oil smoke.

Needsdecaf 06-26-2019 10:14 AM

If leaking turbo seals are an issue than I'm going with that. Sorry to hear of your problems, let's hope they get it resolved.

Rapter 06-29-2019 09:07 AM

Updated provided under June 28th 2019 in the 1st post.

Can you add add oil to the oil filler in the back while the car is slightly angled nose down down the driveway? Does the car have to be perfectly level in order to add oil?

I reviewed the Porsche Parts catalogue and traced the oiler filler pipe down into the engine and could not see any risk to any “oil flowing where it should not flow” on the diagram. I did note that the oil filler pipe does have a “y” connection on it which perhaps oil could go the wrong way... but I really doubt it. I have marked up some images on this thread.

If a car is tilted with the nose down can oil flow to any of these areas and cause engine start up smoke?

Does it matter if the engine is hot, warm or cold when adding oil?

https://cimg7.ibsrv.net/gimg/rennlis...9c60d69ce.jpeg
https://cimg8.ibsrv.net/gimg/rennlis...20362ce81.jpeg

BlackCS 06-29-2019 10:28 AM

I would warm the car up before adding oil, it will become less viscous. Why not just take into service, since the smoke is coming from the exhaust, chances are its a seal on one of the turbos.

Upscale Audio 06-29-2019 10:59 AM

If it has cleared up for now I would still have a discussion with the service manager about expectations if it reoccurs 6 months after your warranty expires.

Rapter 06-29-2019 12:54 PM


Originally Posted by BlackCS
I would warm the car up before adding oil, it will become less viscous. Why not just take into service, since the smoke is coming from the exhaust, chances are its a seal on one of the turbos.

Car stopped smoking while at the dealer and so they did not look into it other than reset the computer and update me to the latest software.

Dealer added additional oil at .6L seems to be fine for now.

I agree with the post above, where a conversation with the manager needs to happen to understand better.

spdracerut 06-29-2019 02:42 PM

Quite possibly a failed air oil separator. Your intercoolers and all the piping are likely full of oil. A somewhat easy area to check is the turbo compressor inlet tube on the passenger side. Pull that off and it's probably coated in oil.

Rapter 06-29-2019 04:16 PM


Originally Posted by spdracerut
Quite possibly a failed air oil separator. Your intercoolers and all the piping are likely full of oil. A somewhat easy area to check is the turbo compressor inlet tube on the passenger side. Pull that off and it's probably coated in oil.

Can you mark up a parts diagram or an google image of the car illustrating the area you are talking about.

I would most likely get at it if it is easy.

spdracerut 06-29-2019 05:01 PM


Originally Posted by Rapter (Post 15941576)
Can you mark up a parts diagram or an google image of the car illustrating the area you are talking about.

I would most likely get at it if it is easy.

This clamp holds the ~180 degree inlet tube to the compressor inlet of the turbo on the passenger side. The air oil separator connects to the middle of the U-bend of the inlet tube. There may be some hose clamps related to that. Not sure if you have to undo those to slide the inlet tube out of the turbo inlet. The tube is plastic, so be careful not to break anything.

https://cimg0.ibsrv.net/gimg/rennlis...7085285aa7.jpg

Rapter 07-02-2019 10:32 PM


Originally Posted by spdracerut
This clamp holds the ~180 degree inlet tube to the compressor inlet of the turbo on the passenger side. The air oil separator connects to the middle of the U-bend of the inlet tube. There may be some hose clamps related to that. Not sure if you have to undo those to slide the inlet tube out of the turbo inlet. The tube is plastic, so be careful not to break anything.

https://cimg0.ibsrv.net/gimg/rennlis...7085285aa7.jpg

Full disclaimer... I did not have the time to review this.

Parked the car this afternoon after a couple wot sustained moments (lots of fun of course), once parked I allowed the car to idle for 45-60 seconds to cool off from the wot.

Started the car about 3 hours later and it smoked terribly bad... similar to near zero visibility.

Drove home in stop and go traffic, parked at the house and restarted the car an hour later... no smoke on start up.

I am thinking there is something about driving the car super hard and wide-open- throttle that is allowing oil seepage???

Will try again tomorrow.

Car is booked into the dealer again Friday.


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