irover

Does anyone have any experience with worn out pop off valve and the results that may produce? Would it be likely that it could wear out at all so that pressure leaks back on the turbo's suction side, and is this a common problem on the 930 with K Jetronic?

thanks for your help.

Brent 930

Stock or aftermarket?

irover

stock of course. The big piston that moves inside the manifold.

Brent 930

Not sure if air will leak when worn but I would replace the seals if they are.

irover

yeah i did by when the bore itself is worn the air passes around the piston i guess..? seals are only sealing the ends of the piston.

casati

What does something like cost to repair, any idea? Thanks

Garibaldi

The gaskets at either end of the bore is to cushion the impact of the piston hitting home at either end, the clearance on the piston to bore is what seals the chamber. The gaskets get old, brittle and soften up with oil saturation and fall apart. If you idle the car and just tap the throttle and hear a clicking noise, then the gaskets are gone. Worst case, i worked on a 930 that has a boost leak, and the gaskets had been gone for so long, that the piston had hammered the rear cap plate of the bore so much that it was cracked and had a huge vaccuum leak/boost leak.