Bought an 86 F-150 with 302EFI and AOD. Got it cheap because the transmission needs work. Oil pressure is 40# at best, goes to 10# at hot idle and up to 30# when reved-up. Compression is consistant on all cylinders at about 120# plus or minus 5#.

What should compression be?

Truck has 130,000 miles. It is all original, clean, rust and dent free, but was neglected on maintenance. Looked like oil and filters hadn't been changed in years.

 

Direct easy answer..... consistent, if your within 5 psi on all cylinders, and your in the 120s,Id say thats pretty darn good, especialy for 130,000 miles

What weight oil are/were you running when you got those fiugures?

 

with that many miles your compression sounds good. mine has 186000 miles on the bronco and i am about 130-140 in all cylinders. as for oil pressure, that sounds like your pick up screen might be a little clogged. i jsut changed mine and i am at 65-70 psi at start idle and about 40-50 psi sruising.

kne

 

That was prophetic. We took the oil pan and valve covers off today and the oil intake is almost completely clogged with chunks of gasket material, some as big as a postage stamp, with some more in the oil pan. There are also bits of red silicon all over the place. The oil pump, valve springs, rockers and most everything are covered with gritty goo. The drain holes from the rocker arms back to the oil pan are about half plugged. The only thing clean is the back side if the pistons themselves.

The red silicon probably came from one of the valve covers, because there's plenty still there. Looks like it was put on with a spoon. I don't know where the black chunks came from.

Is is possable the the oil pump has been grinding up bits of gasket and pumping is around? I'm no veteran of engine work, but this is far and away the filthiest one I have ever seen. Changed the oil when I got it, whish I'd thought to cut the filter open and look.

 

That is what seized my oil pump right there. old gasket wearing out and getting pumped throough. you couldnt even see the pickup screen on mine and couldnt turn the rod to the oil pump at all either. dont forget the distributor rod either.

 

An engine I rebuilt had the silicone worms; but much of the material was degraded valve stem umbrella seals, so check those, replace them and you'll save some oil: if a valve job is not to be done at this time,