I've never performed a compression test/leakdown on my 930 personally, but I have changed the plugs. It can definitely be done with the engine in the car. The intercooler and air filter assembly have to come out.
- '00 Dodge Viper GTS - Steel Grey - Yep...a domestic.
- '87 930 - Guards Red - Sold
- '82 911SC - Grand Prix White - Gone
- '78 928 - Silver - Long gone
- '04 Subaru WRX wagon - Daily grind-mobile