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'90 964 C4 PPI compression/leak down

 
Old 08-23-2016, 05:58 PM
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2000m2
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Default '90 964 C4 PPI compression/leak down

Hi All, looking at getting my first Porsche and had a PPI done.

Here are the compressions and leak down results:
CYL. #1: 8% LEAK, 210 PSI
CYL. #2: 12% LEAK, 220 PSI
CYL. #3: 8% LEAK, 210 PSI
CYL. #4: 8% LEAK, 210 PSI
CYL. #5: 13% LEAK, 210 PSI
CYL. #6: 10% LEAK, 220 PSI

Any input would be greatly appreciated! Is a rebuild in the near future here?

Thank you
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Old 08-23-2016, 08:57 PM
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Steve Weiner-Rennsport Systems
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Hi,

The purpose of leakdown testing is not only to generate a figure, but to note WHERE any observed cylinder leakage comes from and if the technician didn't put that on the form, he failed to do his job.

If the above results came from the valves, I would suggest running a few bottles of a GOOD fuel system cleaner through there to clean the intake valves and then retesting.

How many miles on the car?
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Old 08-23-2016, 09:08 PM
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Originally Posted by Steve Weiner-Rennsport Systems View Post
Hi,

The purpose of leakdown testing is not only to generate a figure, but to note WHERE any observed cylinder leakage comes from and if the technician didn't put that on the form, he failed to do his job.

If the above results came from the valves, I would suggest running a few bottles of a GOOD fuel system cleaner through there to clean the intake valves and then retesting.

How many miles on the car?
Thanks for the reply. I suppose these fellas failed to their job as they did not indicate where. They also suspected the valves not seating though. Further corroborated by the fact that the current owner mentioned he rarely gets up over 4k rpm.

What would be a good fuel system cleaner?

109k miles currently on the car.
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Old 08-23-2016, 09:20 PM
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Steve Weiner-Rennsport Systems
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From your description, its most likely that the engine is heavily carboned up and needs some hard use.

We use, recommend and sell LubroMoly Jectron & Ventil Sauber. Used together, these are make a potent cocktail that works very well.


Put one can of each product in a near empty tank, fill it up and then go put 200 miles of hard driving on the car, followed by an oil change.
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Old 08-23-2016, 09:23 PM
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Originally Posted by Steve Weiner-Rennsport Systems View Post
From your description, its most likely that the engine is heavily carboned up and needs some hard use.

We use, recommend and sell LubroMoly Jectron & Ventil Sauber. Used together, these are make a potent cocktail that works very well.


Put one can of each product in a near empty tank, fill it up and then go put 200 miles of hard driving on the car, followed by an oil change.
Awesome, thanks again for the replies! If I close the deal here, I will order some.
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