Leak down or compression for M97 engine?
 

Hi everyone:

I'm looking at my first water cooled Porsche which is a Cayman. When I bought my air cooled I had leak downs and compression performed.

Should I have the same done for M97 engines, or is there a way to determine this by the Porsche computer?

Yes, do it as part of a PPI, including dropping the oil pan if you're not willing to roll the dice. Same things you would do for an air cooled. ECU holds only overrevs and hours on the engine (well, for that dash actually) for permanent reference. Everything else is only short term issues.

Make sure you pull open the oil filter and check for shiny ferrous metal bits! And then overtime you change the oil thereafter.

edit: every time

With the factory scanners you can look at the engine roughness. If I remember this is in units of 1 rps. The scanner will give values on each cylinder and the threshold varies per engine rpm and load but the threshold value is listed also in the scanner. If the vaues are higher on discrete cylinders you have a problem. Watch for cylinders #2, #4, and #6. These engines are famous for seizing pistons especially high mileage or track engines. Due to location it is time consuming to remove plugs for compression and leakdown. Cannot be done on a hot engine. If you do decide for the expense of doing a compression and leakdown, borescope the cylinders while the plugs are out.

Great info Matt, thanks for posting.

I would be more concerned about the IMS/shrapnel in the oil than compression. If the engine is that down on power I would think you could tell after a drive and listening to the exhaust note.

Will a ppi shop split an oil filter? (assuming the seller is ok with that).

Any proper indy shop will pull it apart. Clearly the filter will need to be replaced. It opens like a cardboard accordion and it can be quite telling as of that day clear or not.

If the seller will not let you change/open the filter don't walk RUN away.