Volvo Repair: Engine ticking/clicking, feed tube, o ring

Question
I have a 1999 S80 that runs great but there's a very noticable ticking or clicking sound coming from the engine when running.  It's loudest as soon as the engine's been started and seems to not as loud after being driven for a while.  Your thoughts?

Thanks

Curtis Allen

Answer
curtis, we see this problem from time to time, and what the problem is, is that the oil pump feed tube o-ring has broken and air gets sucked in causing the noise.  We call it an oil pan reseal.  All the o-ring have to be replaced.  Also, there could be a lifter sticking but usually, this oil pan reseal does the trick.  Roger