The suggestion of the sending unit is a good one, one other thing to
consider would be to temporarily install a mechanical gauge into the sending
unit location and determine just what kind of oil pressure the engine has.
I dont know what kind of mileage the engine has on it, or anything else
about it, except its a smallblock built circa 81. One possible scenario is
a lot of carbon and sludge buildup in the oil pump pickup screen which is
trying to starve the oil pump inlet. At an idle the demand is not so high so
the light goes away, the reverse happens at higher rpm and the oil cant get
into the pump fast enough. I have seen instances of engines that had the
original nylon timing gear teeth clogging the screen but those were in
rather high mileage engines also. Another possibility is the oil return from
the cylinder heads and lifter valley is full of carboned up crud and the oil
takes a longer time to get back to the pump inlet.
As far as the ticking, its a typical Mopar lifter noise. I know from
experience my 318 in the Plymouth is a quart + low on oil and I will hear
them tick on first start up. Kind of a built in oil level device :) The
fact that the ticking goes away is indication that the lifters are pumping
up and theres at least enough oil pressure available for that. When the
noise wont go away, thats a different scenario. I had the unfortunate
experience of hearing that noise from all 16 lifters and watching the oil
pressure fall to zero several years ago on my 440, luckily I was driving in
town at low speed and able to shut down immediately. The problem was a
sheared pump drive, which I doubt is an issue here.
Short version....install a mechanical gauge, check the pressure available,
change the oil and filter and cross your fingers!
Mikey
62 Crown Coupe
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