No oil pressure?

My "shop truck" 72 Ford seems to have no oil pressure when warm and at idle. It runs at 50 psi when cold, then drops when it heats up to 0 at idle and about 20 when driving. The odd part is that the motor is quiet at idle and only makes a little bearing noise at higher RPMs. I am unsure of the mileage on the engine but it looks to have low miles on it and looks like new with the valve covers off (it's a 400M).I don't feel like putting a HVHP oil pump or bearings in it as it uses oil also. I changed the oil and put 5 quarts of 20W50 in and it made little difference, so when it was low I added a quart of 70 wt racing oil.

Is there any way to cheat to get the pressure back up or shouldn't I even worry? I have driven it 5,000 miles this way, I just put a set of new gauges in, this is why I am now concerned.

I'd just like it to last the rest of the summer when I can get a 460 ready to swap in. Any remedies or should I just smile and run it until it blows up?

 

I had the same problem with the 351c in my panel. I drove it to Paso with only 20lbs of pressure on the freeway. So when I got back I changed the oil to straight 60wt and now I have 50lbs at idle. I'm hopeing that this will hold up for one more run to Paso in Aug. and then to Billetproof in Sept. I'd put some 70wt in if I were you and just drive it. Good luck.

 

I think its ****in' fords. I've had three Lima motors in my roadster and none of them have made any oil pressure when warm. The current one makes about 20 psi on the freeway, but they don't seem to care.

 

Heres a formula for you to use to calculate life expectancy of a motor:RUNNING DOWN THE ROAD OIL PRESSURE
zero to 20 pounds oil pressure-Ford= about two years driving at least.
zero to 20 pounds oil pressure-Chevy= 30 minutes tops........

 

I put 3000 miles on a 221 Ford v8 (early early SBF) in case ya didn't know. Made for only like 2 years '62 and '63....

Anyhow, this weezy engine was getting 20lbs cold and 5 to 0 at idle warm... 3000 miles like that and it was still running when I pulled it.

It smoked like a James Bond car on the getaway and was missing pretty heavily....but it was still running.

FWIW.
Run that ****er till she ****s on ya.

 

Are you running a Fram oil filter? I've heard they are so restrictive that they can drop you oil pressure considerably.

 

Has the engine been apart recently or is it just high mileage? You say it looks low mileage, but...

I have seen the oil gallery plugs for the lifters back out (or left out!) & produce exactly these symptoms.

Also, are you running electric or mechanical gauges. If electric, get a cheap mechanical one & just run it under the hood & see what you're really running. I've seen electric gauges off by a lot (usually mis-matched sending unit - even from the factory!)

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and only makes a little bearing noise at higher RPMs.

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This is what I'd be worried about - if you're SURE it's bearing noise, the engine won't last all that long.

Finally, I've never had luck with 351M/400M engines - the 351M engines seemed prone to throw rods IMO & oil pressure has always been dubious.

Just a few places to start...

 

I bought the truck from a guy that said the engine was a r/b motor from Ford. It's completely stock. How long ago was it rebuilt, it could have been 20 years ago as the truck just turned over 100K last week (I know that for sure). I know little about the history of the truck.

It sounds like bearing noise to me, but I am no engine expert. If I am cruising about 50 MPH or so with the windows down I can kinda hear that engine noise that sounds just like a bad bearing, like in a water pump, but louder.

As for the oil filter, it had a Pennzoil (which is a Fram). I changed it to a Motorcraft when I put the other oil in. I am running a set of TPI Tech gauges that are electric...

I have been doing more research accross the net, low pressure is very common on these, even on r/b ones. I know that oiling systems on these engines ****, but I never thought they were that bad. Thanks for the help!

 

If I was gonna build the motor I would stop driveing it. But since you are swapping it out keep thick oil in it and let 'er rip. It'll either hang in or not.
If it doesn't make the summer then you'll just have to hurry the 460 along.
It should start clattering a while before its ready to let loose. Then you better be thinking serious about that new motor.