351W Low oil pressure at engine idle.

[Okiesnake]

351W Low oil pressure at engine idle.
The engine seams to be running OK and feels and sounds strong.
My 351W’s oil pressure at idle drops down to around 10 PSI when warm. The engine has less than 500 miles on it. When cold, the engine runs at about 40 psi at idle and about 60 PSI with engine speed over 2,000 RPM’s. After warming up the pressure is about 25 to 35 PSI except at idle when it drops down to 10 PSI.

For the first 300 miles the idle pressure stayed around 40PSI then recently it dropped down to 20 PSI at idle. I change the oil around 400 miles hoping this would help. I used Mobil 1 10W-30 and used a Ford performance FL1HP filter. I have a remote oil filter and an oil cooler.
Help! I am worried.
Okiesnake

[Cobranut]

Okie,

I wouldn't run that motor any more until you can get it checked out.

I'd be leary of anything under 20-25 psi at hot idle, and you generally want 10 psi per 1000 RPM at speed. IE: 50 psi at 5000 rpm, 60 @ 6000, etc.

The drop after 300 miles indicates something changed in the motor. You could have a bad bearing or it could be the oil pump picked up a shaving missed during block cleaning.
It could also be as simple as a stuck relief valve in the oil pump.

Just have it checked before more severe damage is done.

Good luck,
David

[Rick Parker]

If you have the filter that you recently took off carefully cut it open and look for signs of a bearing material or other foriegn material. One thing to also consider is the oil pump being used for your application. With a remote filter be absolutly sure the oil is flowing through it the right direction and with an oil cooler and related lines it may be necessary to utilize a high pressure or high volumne pump because of the additional amount of oil that is being moved through the system. Check with your engine builder for recomendations in hose size, use as few 90 degree fittings as possible as they restrict flow considerably, and keep the hoses as short as possible. The engine needs more pressure than you indicate. Also eliminate the possibility of a bad gauge.

Good luck
Rick

[BJGreen]

If you are using an electrical guage I suggest you double check with a mechanical unit. I have had several electrical guages that were much less accurate than the mechanical units.
good luck

[Okiesnake]

My engine uses a mechanical pressure sending unit & guage

[marmmansa]

Are you using synthetic oil for break in I thought it is not recomended untill engine is broken in.

[Okiesnake]

I originally did not use synthetic oil. I was going to wait until 500 miles (after break in). However, I went ahead and replaced it a little early because it was so close.

[marmmansa]

you should talk to your engine builder on when you should go to synthetic I think they say 1500 2000 miles.