Low to no oil pressure at idle

Printable View

11-28-2008, 06:30 AM
ss1970

Low to no oil pressure at idle

I'm new to Club Hotrod so I hope I don't bore anyone with something you have answer before.

I have a 454. After starting I have 55 PSI oil pressure. After warming up at about 2500 RPM I have 10-20 PSI( in 4th gear at 55 mph). At Idle it is for all practical purposes zero( there is oil coming up out of the pushrods however).I just put a new Comp roller cam in and oil pump as the last cam got wiped out on 3 lobes. I bought the car with this problem and didn't know it! The engime presumably had 5000 miles on it when I bought it and when I had the motor apart it was very clean inside with the exception of the cam lobes. In the meantime, there are a couple of lifters if I push down on the push rod compresses so it seems the mechnail lifers are not pumping up? This all seems to be leading to pull the motor out again of which I'm trying to avoid. Any ideas how I can identify the root cause with out pulling the motor apart again? It seems the oil pressure was the same way before I put the cam in. **)
11-28-2008, 06:51 AM
FIDO

When cam lobes got wiped out could have took cam bearing's with it did you put in new cam bearings,or just swap out cams,I think you put in new lifters did you soak them and pump them up befor you put them in?
11-28-2008, 07:58 AM
383 chev

I would say it could be your cam bearings, although i have hade cam bearings go bad and once it was warm it did not matter at all what rpm it was at, it stayed at zero. I see that you said it was like this before the cam swap, was the motor rebuilt, to me it sounds like old worn bearings but not junked out ones. I am going to guess it has the stock oil pump in it also. just my 2 cents.
oh they also say that big blocks are hard on valvetrain.
11-28-2008, 08:19 AM
ss1970

Quote:

Originally Posted by FIDO

When cam lobes got wiped out could have took cam bearing's with it did you put in new cam bearings,or just swap out cams,I think you put in new lifters did you soak them and pump them up befor you put them in?

Thanks. No, I used the old bearings( looks like a big mistake now). I did soak and pump up the lifters.
11-28-2008, 08:21 AM
ss1970

Quote:

Originally Posted by 383 chev

I would say it could be your cam bearings, although i have hade cam bearings go bad and once it was warm it did not matter at all what rpm it was at, it stayed at zero. I see that you said it was like this before the cam swap, was the motor rebuilt, to me it sounds like old worn bearings but not junked out ones. I am going to guess it has the stock oil pump in it also. just my 2 cents.
oh they also say that big blocks are hard on valvetrain.

Yes, teh motor was rebuilt and a stock oil pump went in.
Thanks.
11-28-2008, 09:06 AM
francis blake

Looks like motor pullin time again
11-28-2008, 09:18 AM
36fred

Double check oil

I don't know if you thought about what took out the cam lobes with only 5000 mi.or if you have kept up on what they have done to the oil. They have taken out the zinc to help the catalytic converters, which does not bother a roller tappet motor. But it is eating up flat tappets faster than you can put them in. There is an oil that they did not take it out of, so do your home work before putting oil in a new rebuild. There is an additive to. 36Fred
11-28-2008, 09:42 AM
ss1970

thanks for your advise!
11-28-2008, 10:33 AM
ted dehaan

when you wipe out a cam lobe that ground up cast iron goes into the oil now you have wiped out two cams who knows how many lobes how many miles was it driven with all that metal circulating through the oil sys. ( read bearings ) imho I think it time to pull the pan and check the bearings and clearances......ted
11-28-2008, 11:15 AM
stovens

Tech inspector turned me onto this stuff SFR 100 for my engine rebuild/cam break in.
It is expensive, but goes along way at saving real expenses of engine overhalls. 34 bucks a quart but you use very little per oil change. Good stuff with the zinc you need! http://www.sfrcorp.com/product/9
11-28-2008, 04:38 PM
firebird77clone

No oil pressure at idle = pull it and check EVERYTHING.

Otherwise, you could try dumping a quart of Lucas in and see if it helps any.

If a quart of Lucas does not help then it is DEFINITELY time to pull that dog.
11-29-2008, 06:51 AM
R Pope

No oil pressure=no easy fix. Pull that sucker and redo it. Or pass it on to the next victim!
11-29-2008, 07:21 AM
pat mccarthy

pull it that is a no brainier when the cam wipes it will get up on the pistons skirts and work on the bore s of the block cutting the walls all to hell more grit may work it s way in to cam bearings and working to wear out the oil pump soft parts like bearings and pistons see the iron cam grit as well as good running engine will see trash from valve springs shims and retainers to.it will inbed in the soft parts and work as grinding stones .if your building the engine your self always check that the bottom of the bores on lifter and cylinders have no shape edges some machine shops may miss this if so it will start to shave your pistons as well as the lifters more so on roller lifter blocks big stroke engine need more work on the bottom of bores piston work harder in move out of the bores a bit more loose pistons size add to this as well