I just had my trooper calibrated at Betan last weekend and while it was there decided to get it a compression test. The test results showed with no cylinders exhibiting lose comp. However cylinder 3 and 4 registered 'low' compression at 22 bar (vs 1 and 2 24 and 26). Now the folks at Beta said it could easily be fix by getting a tune up and adjusting the valves. I brought the car today to another Mechanic and he said it wasn't the valves but the calibration of the IP pump and the injectors that causes the low comp on 3 and 4, and telling me that I need to recalibrate the IP pump and the injector again.

I am more inclined to believe Betan because I think that it makes more sense that the valves are causing the low comp rather than the injector and the IP. To my understanding lose or low compression happens when there is some form of 'leak' on the cylinder during the compression stroke which may come from worn out rings or from the cylinder head thru the valves.

Just wanted to get other's opinion on the matter above. thanks!