Re:Volvo 740 GL 1989 B230F engine:
I have had engine failure twice for the same problem: there is a square key on the timing belt sprocket that engages the slot in the crankshaft. First incident, I found it broke/sheared off.... so the motor continues to turn, but the camshaft stops turning. I replaced it with a (brand-new) sprocket from AUtohaus.com, and the car ran for a few days, then failed when the key broke off the sprocket AGAIN. I suspect I did not have the timing of camshaft set right. Power seems down some, and the engine "pings" a lot with good, fresh gas. I don't see how this is related to timing, but on the first crank the rotation of the engine would often nearly stall, despite good battery and starter (they're new).... then the engine would" catch" and make a loud clattering sound. Once started, no abnormal sounds at all except for ping under acceleration. If you make a second attempt to start engine, then the rotation stalling/clattering noise did not re-occur...it was only on initial start attempt. I don't know what the clattering noise could be, as I know the camshaft is non-interference-type. Could doing something stupid like not timing the engine right put some abnormal strain/or drag on the rotation of the camshaft (making it resist rotation abnormally), exceeding what the sprocket key can withstand? I don't believe it could be that the part was bad, I'm probably doing something wrong that broke the sprocket key. The new sprocket didn't break when I was starting, I had driven about
10 miles when it broke/engine died....happened when I was accelerating from a stop.Yes, I understand now that you really can't adjust the timing, you just set the crankshaft position and camshaft position relative to each other.
Ideas?