Here's a follow up to my last post of the same title, trying to solve my engine knock/clack. Had car delivered by flatbed to my garage. Pulled valve cover, checked valve clearances- all good. A good friend hooked me up with a Volvo dealer mechanic who does side jobs. Described symptoms to him. He said it seemed like a broken spring and that if so I should be able to depress the cup with the broken spring easier than the rest. They all seem to be equally stiff,
but I still want to visually inspect them. All valves go up and down, so it's definitely not a stuck valve. Pulled plugs and they all look good. Also started car briefly to try out a new stethoscope that I had bought mail order. Noise seems to come from front half of head. (Remember that #2 ran for a while with a bad injector that was replaced a week prior to the appearnce of the noise with a new injector, along with a new intake manifold gasket.) I will do a compression check next. Volvo mechanic comes by in morning to here the sound. Then we'll pull the cam an inspect the springs. If I don't find anything, then head comes off. If not broken spring, does anyone have any ideas as to what could cause the knock (immediately at start-up.)
Volvo mechanic did mention the his experiences of hydro-locking on start-up caused by a bad injector. This would bend the connecting rod(s) which would then hit the crank counterweights upon rotation. Be he also said he had seen it it 850's and not in a 700/900 yet. And I my injector problem had been fixed already.
So the search for the source of the knock continues. Is there anything I haven't checked or am overlooking?