lost oil pressure Found the problem

Posted By: rowin4

lost oil pressure Found the problem - 02/18/10 12:04 AM

Lost oil pressure at the end of a run yesterday. Looked down as it was dropping to 0. Shut off the engine, coasted off the track. Checked the block , no holes, over full on the oil because of the accumilator, fired it back up , no oil pressure so I loaded it up. Today pulled the dizzy thought maybe the pump shaft may have broke or stripped, perfect shape, pulled the valve covers , thought maybe a rocker or push rod broke allowing a lifter to come out, every thing good there, pulled the pan, not a spec of anything in it. I have never heard of a big block pump going bad or do they. What should I look at next? Usually holds 45-50 at a hot idle and 70-75 hot at high rev's.

Posted By: moparacer

Re: lost oil pressure - 02/18/10 12:35 AM

How much oil did you drain out of it?

It didn't get low and uncover the pickup for a second did it?

Posted By: MR_P_BODY

Re: lost oil pressure - 02/18/10 12:37 AM

Quote:

Lost oil pressure at the end of a run yesterday. Looked down as it was dropping to 0. Shut off the engine, coasted off the track. Checked the block , no holes, over full on the oil because of the accumilator, fired it back up , no oil pressure so I loaded it up. Today pulled the dizzy thought maybe the pump shaft may have broke or stripped, perfect shape, pulled the valve covers , thought maybe a rocker or push rod broke allowing a lifter to come out, every thing good there, pulled the pan, not a spec of anything in it. I have never heard of a big block pump going bad or do they. What should I look at next? Usually holds 45-50 at a hot idle and 70-75 hot at high rev's.

Well I guess your down to the pump or filter

Posted By: DemonDust

Re: lost oil pressure - 02/18/10 12:41 AM

I lost oil pressure on my R5 last weekend. My input shaft bushing fell out of my crank spacer, to the inside of the crank. With the bushing adding that much weight and the clutch being off center. It took out my rear main bearing...

Luckily it didn't wreck anything.....

Posted By: plycuda

Re: lost oil pressure - 02/18/10 12:45 AM

might check and see if something got in the releif valve.Thats what mine did had no pressure at all.

Posted By: 1964maxwedge

Re: lost oil pressure - 02/18/10 12:59 AM

I would check to make sure you ,didn't pop out a lifter out of the bore .I ran into the same problem thats what mine was.

Posted By: CHAPPER

Re: lost oil pressure - 02/18/10 01:16 AM

Quote:

might check and see if something got in the releif valve.Thats what mine did had no pressure at all.

Posted By: Comp_Chassis

Re: lost oil pressure - 02/18/10 01:26 AM

Have you verified that the gauge is actually working? I have seen gauges fail before.

Posted By: rowin4

Re: lost oil pressure - 02/18/10 01:44 AM

Drained out 2 1/2 galloons, pan 7 plus 3 accumitator. Lifter was the second thought, I checked them , all ok Both the gage's are mechanical , both 0. The filters a 2qt. wix racing remote, can't see that just plugging up. I'll pull the pump tomorrow and take a look.

Posted By: strokin73cuda

Re: lost oil pressure - 02/18/10 04:56 AM

Quote:

might check and see if something got in the releif valve.Thats what mine did had no pressure at all.

Is it external fed? May be sucking air somewhere.

Posted By: Rodney

Re: lost oil pressure - 02/18/10 09:03 AM

if the accumulator had oil in it wouldn't you have to have oil pressure for it have been full?

Posted By: challenger1320

Re: lost oil pressure - 02/18/10 08:43 PM

I would bet the bypass is stuck in the oil pump

Posted By: 602heavy

Re: lost oil pressure - 02/18/10 09:12 PM

Oil pick up fallen off?

Posted By: MoparforLife

Re: lost oil pressure - 02/18/10 09:16 PM

Quote:

I would bet the bypass is stuck in the oil pump

Posted By: RemCharger

Re: lost oil pressure - 02/18/10 09:48 PM

Quote:

Oil pick up fallen off?

Posted By: MR_P_BODY

Re: lost oil pressure - 02/18/10 09:56 PM

Quote:

Oil pick up fallen off?

Can that thing un-screw on a BB without crashing into
something(when the pan is on.... maybe broke off
but like some of the others I believe the by-pass
is stuck open

Posted By: rowin4

Re: lost oil pressure - 02/18/10 10:12 PM

Quote:

if the accumulator had oil in it wouldn't you have to have oil pressure for it have been full?

Yes that is correct , but as you lose pressure the accumulator empties to try to make up for the loss of pressure which it did. The engine has a external oil system , the pick up is a static mount , lines were all tight and nothing on the screen. I ordered a new pump today, don't want to have another problem with that one. Hope that's what the problem is. Thanks for the info guy's

Posted By: 602heavy

Re: lost oil pressure - 02/19/10 12:11 AM

Gallery plug fallen out.

Had a flex plate bolt tear the rear gallery plug to bits.

Posted By: Cab_Burge

Re: lost oil pressure - 02/19/10 03:18 AM

Quote:

Gallery plug fallen out.
(quote)
I have had the bypass plug come out of the pump, also had one customers motor missing one of the internal galley plug not installed, the one behind the cam gear Also have had several bypass valves stick in the oil pump, always at,WOT

Posted By: rowin4

Re: lost oil pressure - 02/21/10 06:17 AM

The problem was that the by pass cap unscrewed and let the valve slide out to a point that it wedged and wouldn't return. Removed the cap and spring, inspected the little piston and reassembled. Used some blue lock tight this time.It primed right up with the drill , reassembled every thing I took apart and fired the engine. Oil pressure is back up to normal. Thanks every body for your input.

Posted By: MR_P_BODY

Re: lost oil pressure - 02/21/10 11:51 AM

Glad to hear you got it squared away Steve

Posted By: 440Jim

Re: lost oil pressure Found the problem - 02/21/10 02:11 PM

I had an oil pressure gauge break in the staging lanes when I started the car to go to the water box. Pulled off to the side. I took off the oil pressure line at the back of the block (1/8 tubing) and cranked it over... oil shot out over the fender! A fellow racer gave me a spare gauge and it all checked out fine. Went to eliminations that day and made it to 5th round.

Posted By: 69CHARGERMD

Re: lost oil pressure Found the problem - 02/21/10 02:17 PM

Was it pretty obvious ?,,,ie,,was it loose when you found it ?
glad to hear you got it fixed....

Posted By: Rodney

Re: lost oil pressure Found the problem - 02/21/10 02:43 PM

great

I'm going to be removing the valve and spring on the 572 to adjust the pressure I will add a drop of loctite as well.

Posted By: rowin4

Re: lost oil pressure Found the problem - 02/21/10 04:08 PM

Quote:

Was it pretty obvious ?,,,ie,,was it loose when you found it ?
glad to hear you got it fixed....
[/quote

Yes it was when I removed the cover, I didn't look up into that area before to look at it. Another turn it would have popped out. Left the pump on the block ,just removed the rotor and ring, inspected, greased them up and reassembled.