Shimmed Oil Pump

[float_6969]

Has anybody tried shimming the oil pump on their CA's? I was thinking about doing this to fix my noisy lifters since I'm pretty sure it's from low oil pressure.

[themadscientist]

I've shimmed L and FJ pumps, same concept, stack a washer or two in there under the bypass spring.

Try changing to a higher viscosity oil.

If your lifters aren't getting enough pressure and the pump is known to be good, your crank bearings might be worn out.

[float_6969]

I've used 15w-15 and it still ticks and the pressure is still low when the oil warms up. When the oil is cold, it never ticks.

When you rev it up and the pressure increases, the ticking stops. It's just the idle oil pressure it too low to keep them pumped up.

The pump was new when the motor was rebuilt about 20K miles ago, but the motor has had low oil pressure since the rebuild. I know I told the engine builder that I was going to run boost and N20, and so we decided to build the motor "loose" but I was under the impression that was the in regards to the rings. I suppose he could have run the main and rod bearings on the loose side too, which would explain the low oil pressure. If it's from loose mains, shimming the pump won't help, will it?

What about that check valve in the head that is supposed to be for the lifters? Anybody heard of that failing or getting something stuck in it?

Maybe I just need to go to solid lifters, LOL!

[boost_boy]

I've used 15w-15 and it still ticks and the pressure is still low when the oil warms up. When the oil is cold, it never ticks.

When you rev it up and the pressure increases, the ticking stops. It's just the idle oil pressure it too low to keep them pumped up.

The pump was new when the motor was rebuilt about 20K miles ago, but the motor has had low oil pressure since the rebuild. I know I told the engine builder that I was going to run boost and N20, and so we decided to build the motor "loose" but I was under the impression that was the in regards to the rings. I suppose he could have run the main and rod bearings on the loose side too, which would explain the low oil pressure. If it's from loose mains, shimming the pump won't help, will it?

What about that check valve in the head that is supposed to be for the lifters? Anybody heard of that failing or getting something stuck in it?

Maybe I just need to go to solid lifters, LOL!

Well, definitely don't want to do the solid lifters or you're in for a treat. What's your oil pressure at idle? What is your oil pressure on a cold engine under mid to heavy throttle? Identify which lifters are making the noise and go from there. If they are all making noise, then you definitely have oiling issues. If the noises are intermittent, I would go to a heavier oil. Mine makes noise every blue moon, but they shut up and I just keep on keeping on .

Dee

[float_6969]

Warm idle pressure is about 12psi.

Cold pressure is about 45 @ idle, and it goes up from there with revs.

It's not any particular lifter. It almost seems to move around the head, and like I said, if I rev it up to like 1500-2000, and keep it there, they quiet up after 15 seconds or so.

I have put brand new lifters in it MULTIPLE times and it has no effect.

[themadscientist]

You know what you have to do.



Those bearings are too loose and it's only going to get worse.

[float_6969]

Damn machine shop. At least the crank was never turned so I should be able to follow the grade numbers on the block/crank/rods and get the correct sized bearings from Nissan.

That pic is funny, that is the EXACT same engine balancer I have.

[bentvalves]

before you do anything, I would think that you should try shimming the pump, try to get idle pressure somewhere around 20psi and see if it shuts its filthy mouth. Have you tried using some lucas oil stabilizer?

[float_6969]

Yea, I tried lucas.

I'm gonna try shimming the pump and see what happens.

Any guess as to how much I should shim it?

[boost_boy]

Yea, I tried lucas.

I'm gonna try shimming the pump and see what happens.

Any guess as to how much I should shim it?

Good luck with the shimming, but I don't think it's the problem, champ. My idle pressure on my 240 bounces around as well between 25 and sometimes at or around 5psi (per my digital gauge and electric sender). Like I said before, the lifters will make some noise and will actually affect the exhaust note as well. I know the thing has oil in it and I know the pump is good, so I just let it idle and it ultimately shuts and I'm happy for a while. I know the noise is annoying though, because sometimes it'so loud, you think something is wrong with the engine or it's out of oil. I've found that fresh oil changes helps as well. And you're using a much thinner oil than I am, so I would go for a thicker grade oil before pulling apart the pump. Where is your idle RPM per your in car tach-vs-your sds hand controller?

Dee

[float_6969]

The lifters have ticked since the day the motor was rebuilt. I've tried light oils and heavy oils. I've tried additives and different oil pressure gauges.

The lifters ALWAYS tick once the motor warms up and is idling, they ALWAYS stop once the oil pressure comes up to about 15-20psi when you rev it and hold it there for a little bit.

In car tach and SDS read the same and always have.

I got a hold of my engine builder and talked to him about it. He looked up what he had written down for my motor and told me that we did decide to build the motor on the loose side. The crank wasn't ground, but just polished up a bit, and he used stock sized bearings, but he used Clevite 77's, which are known to run loose. He said if I put a high volume pump in, the pressure should go up, and the lifters should quite down. The problem is that nobody makes a high volume pump for the CA. (supposedly TOGA does, but I hear that they're exactly the same as stock) I don't know if shimming the pump will increase the idle oil pressure, I doubt it will. I will probably have to just get new bearings from it from Nissan, or find a bearing that runs smaller than the Clevite's do.

[bentvalves]

I would still try shimming the pump, but if you dont feel like doing that and want to give something else a shot - use a 20w-50 or 15w-50 racing oil (i use amsoil) and set your idle RPM to about 1200 rpm. If you did use clevites and your oil pressure is indeed accurate at idle, you want to stay away from thin oils and opt for heavier viscosity instead. You have a few options here before you do it all over again.

[boost_boy]

How does the car act if you hold the idle at 1200rpm, 1100rpm, and 1000rpm? The point I'm trying to make is, if you have your idle set below 1000rpm trying to respect the factory suggestions, you maywant to idle it higher if it helps the oil pressure.

Dee

[float_6969]

I would still try shimming the pump, but if you dont feel like doing that and want to give something else a shot - use a 20w-50 or 15w-50 racing oil (i use amsoil) and set your idle RPM to about 1200 rpm. If you did use clevites and your oil pressure is indeed accurate at idle, you want to stay away from thin oils and opt for heavier viscosity instead. You have a few options here before you do it all over again.

I am still going to shim it and I was thinking about the Amsoil 15w-50 too (my father in law is a dealer). IDK if 1200 RPMS is enough, but I haven't tried a 50 viscosity oil either.

How does the car act if you hold the idle at 1200rpm, 1100rpm, and 1000rpm? The point I'm trying to make is, if you have your idle set below 1000rpm trying to respect the factory suggestions, you may want to idle it higher if it helps the oil pressure.

Dee

1200 hasn't been enough, but I do have the idle set to about 1000, so I could bump it up. I might have to with these HKS 264's, IDK how they'll effect idle.

[r34 gtr]

My engine sounds (Edit: sounded) like yours... I rebuilt it on the loose side, i.e. no machine work on the bottom end, just a hone, new rings, clevite bearings. I never had a problem with noisy lifters though. Even when I thrashed two they never made any noise. Try Castrol GTX 10w40? That is my only suggestion.

If its really bothering you, just rebuild it. Do a bunch of donuts beforehand though, just so it is more warranted.

When you shim the pump, do a write-up. Its Not that it sounds hard, I just freaking love pictures.

On second thought, what business do I even have in here? I drive a DOHC KA. (Which might I add is slow as hell)

[boost_boy]

Something I completey re-learned about this motor after all these years is that no matter what, your dipstick readings are not never accurate. I used to be aware of this back in the days when I was in the learning stages. I noticed when my lifters tapped, it was usually time for an oil change. They tapped nasty-style on Thursday and beingso annoyed at te noise, I just left the crap running for 5 minutes and they shut. The next couple of days I would crank the car and indeed the lifters were quiet. But on some days, my digital oil pressure gauge would go as low as zero at idle and I didn't understand why. I always checked the oil, even though my engines don't leak oil and it alwys displayed to me a sufficient amount of oil in the sump. Well, I checked the oil yesterday and it appeared pretty sufficient, but I drained it anyways and "voila" it was pretty low on oil and the gauge is really spot on.

So my suggestion, check your dipstick first, then drain the oil and see how much oil comes out. This should tell you rght away if these are the issues that plague you. I truly don't think this engine and it's pump is a candidate for shimming. It's usually user error or user not knowing that somethings don't work the way they suposed to. Anyways dude, check it out. My own is very happy at this point and I now know when this particular CA of mine is short a quart of oil per dipstick readings. Good luck........

Dee

[float_6969]

Yea, I tried the extra oil thing too. My dipstick reads dead on.