Mike J

Kevin's opinion is that the best oil for the Turbo is the 20/50W Mobil V-twin, which most of us (including myself) are using on our turbos. A lot of us get our oil analysed, and I have noticed reduced metal wear numbers since I started to use that oil.

Porsche has over time gone to much thinner oils, like the 0W or 5W oils, but that oil does not seem to handle the extreme heat variations and soaks the Turbo has. The thing about v-twin is its designed for motorcycle engines, which are inherently the same as our air-cooled engines. The oil has very good tolerance of localized hot spots, which we experience especially in the turbo bearings when the car is shut off after a run (even after the recommended 2+ minute cool down). The downside is when its cool (like now in Vancouver) you can pickup some issues like slow pressurization of the lifters for a few seconds, but its not a bit issue.

Cheers,

Mike

rlme36

Drink the cool aide, you'll like it :-)

ronnie993tt

You guys with the ???s - and they are good ones we all had - should do a bit of search and reading. This stuff has been discussed to death on this forum..

DRPM

good refresher...

Mike J

and cool-aide apparently.

rlme36

I have to say, I thought rather witty myself.

LexVan

What, you have doubts?

Spyder34

So what decisions have you made Paul?
I was in a similar situation- maybe you saw my thread from about 1 month ago and my update. I bought the 28k mile '97 993tt despite lousy leakdown numbers during PPI due to everything else checking out fine and attributing the (consistent but) high %'s to inaccurate testing. Subsequent leakdown done by another indy shop showed 2%. Sleeping better now.
How about an update on where you are now in the overall process and what's gone into making your decisions?

Healeyguy

Hi Mark, I decided to not pursue the car. I don't believe that a car with only 14k could have such consistent poor leak down results. However, I'd be shipping the car 4k miles and couldn't take the chance. I was hoping the vendor would step up and have some more research done. I spent quite a bit for the initial PPI and didn't think that I wanted to put more money into it.

pstoppani

As Mark's experience shows, a proper test is needed. I'd have another shop do another test...

ronnie993tt

+1. I don't believe the test.........

FELKER

What are you your opinions on these leak down and compression values.. 67,000 miles. Have been burning oil terribly, now have the check valves installed and the oil cleaned out of the intake ducting, and intercoolers, which were "full" of oil.. 15w50 Mobil 1 now in there.. with Porsche Filters.. No oil burned at start up and anytime that I can detect.

Mechanic was not "confident" in the validity of the #6 cylinder values, he say he never seemed to get a good seal due to the angle he had to place the gauge.. as told to Drive for 1000miles and recheck..

Cylinder Compression Leak down

1. 130 3%
2. 130 3%
3. 130 4%
4. 130 4%
5. 135 3%
6. 120 60%

pstoppani

Have it checked by someone else...

Mike J

The "angle" is no different on #6 , he does have to access it through the port from below, but I have had no issues. The end of the tools are threaded into the sparkplug hole, so it means he is not getting the tool threaded tight. Not sure how someone would be able to use that as an excuse - weird.

Also, if you do get a out-of-bound leak-down, the mechanic should tell you where the leak is coming from (i.e. exhaust valve would produce a sound from the exhaust, intake value - sound at the intake, and rings -sound at the case breather tube).

I agree, move onto a mechanic that knows what he is doing.



Cheers,

Mike

Bgoldey

The PPI is only as good as the person doing it. It's been my experience that although there are a tremendous number of aircooled Porsche experts, few truly know the 993tt.