Oil Pump and Lifters

**Wayne P.** · October 1, 2003, 06:12 AM

Re: Oil Pump and Lifters

If you've got 30 psi, oil pressure isn't the problem. Yes, you could cause problems by over tightening. If your nuts aren't backing off, I'm still betting on worn cam lobes.

**Kevin Morris** · October 1, 2003, 10:28 AM

Re: Oil Pump and Lifters

I'm very interested to know the answer to this one, too. I have noisy hydralic lifters as well...and my engine was just rebuilt 4k miles ago. The rebuild included new cam, lifters, oil pump, etc., etc.

**Ray C.** · October 1, 2003, 06:35 PM

Re: Oil Pump and Lifters

Hi!

What type of hydraulic lifters did you use?

Ray

**Clem Z.** · October 1, 2003, 06:51 PM

Re: Oil Pump and Lifters

check to make sure that your rebuilder did not use "rhoads lifters" as these are a "bleed down" type lifter that make noise up to about 2500 RPM

**Jim K.** · October 2, 2003, 05:33 AM

Re: Oil Pump and Lifters

Mine were making noise all the way through 4000+ rpm. Is there a way to test an oil pump? What should it read @ idle? Mine seems to read low 10+/- and climbs w/rpm but fals sharply when backing off the peddle.

**Kevin Morris** · October 2, 2003, 01:12 PM

Re: Oil Pump and Lifters

Jim, I wouldn't be too concerned about the oil pressure. My SB does the same thing, more pressure with throttle, less pressure at idle....this is common. As the previous poster stated, as long as you are making minimum 30-35 lbs. all of the time, you're fine.

**Clem Z.** · October 2, 2003, 03:54 PM

Re: Oil Pump and Lifters

i think he posted that he only had 10#+ - at idle and that ain't good.

**Chuck S.** · October 2, 2003, 06:35 PM

Re: Oil Pump and Lifters

Jim, you said the engine was rebuilt many years ago and that you have put 2K-3K miles on it the last couple of summers, but you didn't say how many miles the rebuild has on it. Have you purchased the car a couple of years ago, and don't know the mileage on the rebuild?

Rather than assume that the oil pump is weak, I believe I would remove some bearing caps and check some clearances once the pan is dropped. It may be time to give the old gal another freshening up. Engine life will depend on quality of its maintenance, and also, sellers have been known to misrepresent the "time since rebuild". My car's previous owner said the engine had "recently" been rebuilt...Yeah, right...when I checked it out to determine if any engine work was necessary, the copper backing was showing on several bearing inserts.

**Jim K.** · October 3, 2003, 05:33 AM

Re: Oil Pump and Lifters

Yes Clem, and I don't remember exactly how funky the needle was acting (because I haven't had time lately to play with it with work and RedSox games), but it was almost like the pressure dropped at a high rpm, was O.K. at mid range and very low at idle. I picked up a new oil pump yesterday and will put it in tonight, any thoughts on what to watch out for in doing this?. I'll let you know what I find, thanks Clem!!!

**Jim K.** · October 3, 2003, 05:41 AM

Re: Oil Pump and Lifters

Thanks Chuck, I don't know who or how the engine was rebuilt, but it was not installed since rebuild and was extremely clean inside when I was checking it out. After the first summer I did replace the rear main seal that was leaking so it may have sat for a while and dried out. When I took the rear cap off it looked good. Otherwise the engine runs strong without any smoke and compression is 190 - 200.
Chuck, other than overall overall potential poor workmanship in rebuilding, is there a direct relationship of bearings and oil pressure or lifters?
Thanks Chuck!!!

**Chuck S.** · October 3, 2003, 10:23 AM

Re: Oil Pump and Lifters

Jim, my belief is that low oil pressure at idle is more frequently an indication of too much clearance in the bearings than a worn oil pump. As you say, poor workmanship or, in my opinion, improper break-in could also lead to premature bearing wear. From your last post, I assume that you installed the rebuilt engine and did the initial startup yourself. That makes the total mileage on this rebuilt engine at 2K miles???

My engine rebuilder told me that small block oil pumps are usually good enough that there is a temptation to reuse the oil pump on a rebuild rather than run the risk of getting a bad one new out of the box. Sort of "the devil you know rather than the devil you don't know"...He replaced mine. If you think about it, about the only way a gear pump can wear running immersed in oil, is if you are feeding it really dirty oil, and for a relative long time. I believe it is excessive end clearance between the rotors and the housing that usually causes them to not put up required pressure.

IF, in fact, your engine was rebuilt as stated by the seller, and the oil pump was not changed, that MAY make the weak oil pump theory feasible. It is strange that you are not having any top end problems that result in poor performance. I would still check the bearing clearances (plastigage; torque the caps) before I changed the oil pump.

I can't add anything to the good comments others with expertise have already made on lifters and oil pressure.

**Jim K.** · October 3, 2003, 11:16 AM

Re: Oil Pump and Lifters

Chuck:
Thanks for that lesson, now I understand the correlation. Looks like plastiguage is on the menue for tonight. Do you know what numbers I should be looking for???
Thanks again Chuck!!!
jim

**Chuck S.** · October 3, 2003, 06:08 PM

Re: Oil Pump and Lifters

Jim, I don't know any product numbers, but your auto parts store guy should be able to help you. To confirm what the counter guy is saying, I would probably look up the clearances for the rods and mains in the service manual just to know the approximate spec range.

If you haven't used plastigage before, it's like a thread of soft, conformable plastic. You lay the thread around the bearing insert half, replace the bearing cap, and torque the cap to specifications. Then you remove the cap and use the calibrated gage supplied with the plastigage to measure the "squashed" thread to determine the bearing clearance.

Make sure the caps go back in the same position you remove them; same bearing, same direction. If the engine has been rebuilt, the caps will probably be marked with punch marks somehow, but I would still only do one bearing at a time to minimize mixups. BTW, if I have told you stuff you already knew, my apologies.

Oil Pump and Lifters

Oil Pump and Lifters

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