Hrmm, weak oil pump... is this at all likely? How can I test for that?

It is possible. But it is unlikely. Bearing wear is much more likely. See what the pressure is after an oil change on the first start of the day when the oil is thickest. If you can't get 40 psi with 15W-40 in a cold engine on start up, then you can increase your level of concern.

There may be an easier way, but the only way I know to check the oil pump is to pull the front cover, undo the pmp cover, measure the clearances and compare them to specs.

If it were me, I would do the easiest thing first, and see what the heavier oil does. If still low on pressure, I would install a mechanical gauge in a T with the sender. If still low, I'd go looking for a good used engine, cause for me, it is always the bearings and never the pump. But hey, who knows? You could be the lucky one (?) and have a failing pump.

what about the mechanical gauge idea?

I get 60+ psi on cold start up at idle.

IMO, the bearings would be easier to change. I'm gonna buy a gauge this weekend, probably.

Yeah Hans, you are right. There is good reason to test the dash gauge first with a mechanical unit. If he finds the gauge is reading lower than it should, he could try a new sending unit or a new dash gauge, or just mount the mechanical gauge permanently. If the dash gauge is reading OK, he can then try the thicker oil.

But if he doesn't test it first, he won't know at all.

Thanks for making me think a little more about it.

Many believe that changing the bearings without resurfacing the crank journals is a waste of time and money, and can even cause trouble because the worn journal chews up the new bearings making sparkly little abrasives for all the other bearings and material to plug up little passages in the oil gallery like your lifters for example.

I have changed them it in the past with and without grinding the crank, and there is no comparison. What usually happens is you see an initial improvement, and a few months later you are back to where you were with clearance and pressure.

Seeing that your gauge is reading 60+ in the morning, it would seem that the gauge is not too likely to be wrong. So, Hans, now I am back to my recommendation of changing to thicker oil first to see what happens. It is cheap and easy and won't hurt anything.

The oil smells a little like gas, but not much.

Most fuel would evaporate normally, leaving only a small smell.

Hey guys..what is the name for the type of oil pump we have. I've seen one, the type we have is good and would not fail or get weak in most cases.

it'* called a "gerotor" style pump which is a combo of gear and rotor pumps.

very good pump,,long lasting.......

Could be his spring loaded oil pressure relief valve too...

it'* located in the timing cover,, that regulates the oil pressure.,,somthing too to think about.

spring could be weak or even broke,,seen it befor

here'* where it'* located;

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