[cmcfaul]

I have a new to me Carerra with stock 3.2 and about 100K miles on it. It burns no oil, has no leaks, no smoke and runs OK. Starts right up idles a bit lumpy and runs to redline ok when the radio is on :-)

I have owned old 911's and rebuild two engines. Still not expert by any means.

Car seems slow. Did a valve adjustment and most were tight. Also did cap, rotor, wires and plugs. Now it runs a bit better and have been feeding it some Textron to clean off deposits.

Between 4k rpm's and 6k rpm's there is a knock on the right side. I suspect it might be a stretched timing chain. I theorize the stretched chains is also throwing the valve timing off a bit...thus the slow car. All 6 plugs have identical wear and seem to be getting the right mixture.

Since everything else in the engine seems healthy, can the timing chains be changed with the engine in the car? Or, am I looking down the wrong path.

The chain can be cut and new chain attached and cycled through the engine. My fear is the chain comes off the sprocket in the engine.....then case has to be split to repair. Also, don't want to have to time the cams (PITA) so hoping new chains will bring it back to spec.

Let me know your thoughts.

Thanks

Chris