4.6 liter sohc

It sounds like you either have a clogged pickup screen or the drainbacks from the heads are pluged reducing the oil available to the pump. You should check the pressure with a mechanical guage before doing a lot of work. If it is a restricted.reduced oil supply, it won't make any difference if you are driving or not as long as the engine speed is there. If this is the problem, the pressure may hold a bit before dropping.

Lugnut

Amen Lugnut, you beat me to it. Restricted oil pickup most likely. I've seen this a (very) few times on poorly maintained 4.6s. BTW, don't waste your time trying to clean it. A new pickup tube is less than $20. Pulling the pan is a real bear, don't take chances on the old pickup.

This condition used to appear with bad camshaft bearings on old engines. I don't know if applies to newer engines however.

Didnt beat ME to it... I resisted the opportunity to once again rant about the famous highly advertised oil, combined with extended times between changes, combined with short engine use cycles.

Do a dipstick tube swab.

Ur preachin' to the choir boys!

Lugnut

Did I mention I once received a nasty email from a Sertain lube Qompany.. about naming names? Left me Kwuaking, I tell yer..

It's when I discovered that corps also used gophers..

Left ur a** smokin' - huh!

Lugnut

FWIW,

The Oil pressure gauge found in 94 and 95 4.6 T-Birds is really just an idiot light. It is wired to a simple off/on sensor with a series resistance to put the gauge needle in a good spot.

That covers pretty much all the Fords now for over 20 years. It is possible on some of them to install a variable sender to make the guage linear, but, hell, not many people understand that some variation is normal. That is why I think Ford just went to the all or nothing guage. It gives the ignorant paranoid driver a bit of security by knowing the engine has good oil pressure at all times - until it fails.

Lugnut

Would that apply to the trucks, also? I have an F-350 SD TDI at work and have been impressed by how stable the oil pressure guage is. Maybe I shouldn't be that impressed?

Mike

I know it is true for the F-150

The gas burners are. I do not know for sure about the Diesels. I'll bet you have been blissfully happy with your unbelieveable steady oil pressure - exactly as it was intended.

Lugnut

I've been too easily impressed, then