Now that the picture unfolds, things are becoming clearer. The
oil pump is not faulty (althoughit is now scarred from running dry). The pressure relief valve, although weak was not the cause of the failure either.
The mechanic started the car several times after the
oil change and there was no clattering of valves like there is now, the
oil pressure seemed fine (although they did not check the guage).
When the test drive began the mnotor sounded fine and there was no reason to suspect anything. During the test drive the mechanic heard the clattering and noticed the oil pressure guage was on 0 but he thought the guage must not be working. He pulled over and then decided the rattling indicated no oil pressure and had the car towed back.
Turns out the builder of the car had extended the oil pan to increase the amount of oil for the big engine and
he thought he had relocated the oil pump pick-up to the real of the pan but he had not.
Not sure, but I think what happened is that the mechanic put in less oil than was previously in there, (11 quarts is needed) and during the test drive the oil sloshed to the back of the pan and the pick-up drew air causing the pump to lose prime.
Now there is scoring (uneveness) on the crank at the end rod bearings and on Monday we will pull the crank to see the extent and perhaps have it turned/polished.
I wonder what more damage will have been done! The mechanic tells me he has put his flashlight on to the cam and everything up there looks perfect. Still, now there is metal filings visible in the pick-up screen and I suppose filings have travelled through the motor?
Some oil change!!!!!!
Any advice would be appreciated very much.
Someone asked about the drive rod ... it was fine.
Someone suggested priming the oil pump before restarting, How do you do that? Mechanic couldn't see how toget oil up through the pick-up without it just pouring back down. Is there some method to this?
Thanks Guys,
Greg.