High Volume OR High Pessure Oil Pump?

So my Jeep has almost 170K After Replacing the cylinder head and lifters i still have some Lifter Chatter...only when warm...I run 10W30 Synthetic Blend.
Have ran Heaver Weight oil which makes it worse...so i think i have a issue with oil pressure.

I have heard of some Putting High pressure pumps in to help with the Worn Bearings and low pressure issues....I need to do a RMS soon and while i Have my pan off i of course want to replace the Pump....What do you guys suggest? Oh and im Not interested in a Rebuild right now or replacing the Bearings......

98 jeepjeep said:

So my Jeep has almost 170K After Replacing the cylinder head and lifters i still have some Lifter Chatter...only when warm...I run 10W30 Synthetic Blend.
Have ran Heaver Weight oil which makes it worse...so i think i have a issue with oil pressure.

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What's the oil pressure gauge reading at idle and under normal driving?

I have heard of some Putting High pressure pumps in to help with the Worn Bearings and low pressure issues....I need to do a RMS soon and while i Have my pan off i of course want to replace the Pump....What do you guys suggest?

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Here's my concern with going straight to a high-flow / high-pressure oil pump: while it sounds like there's a possible low oil pressure issue, there may be something in the rebuild that's causing the issue which is not related to the oil pump. By replacing the pump with a higher-volume unit it you could be addressing the symptom, not the cause.

Let's back up a little here, because it sounds like this was an issue before the rebuild. What did the rebuild consist of, and what issues prompted you to undertake the rebuild? How bad was the problem before the rebuild, and what was the oil pressure like at that point (idle and load)? Was the OEM oil pump inspected or replaced as part of the rebuild, or was the old one reused?

Engine was NEVER rebuilt...I have a Cracked Head and Removed it and also Replaced the Loud lifters.......Oil pressure Use to read 20psi at idle and around 40 Cruise...HOT But i snapped that Original Sender off during the head swap and replaced it with a GP Sorcen From Advance Auto which Reads 35-40 at idle and 50-60 Cruise...which i know isnt RIGHT...However i Have not put a Mechanical Guage on it...But from my experiance with Hydraulic lifter they get Noisy when worn or pressure is low.

So i was thinking a High Volume Or High Pressure pump would Cure this...However i now it is just a Band aide for Excessive Bearing Clearence.....But i would like to see how many miles i can get out of the 4.0

im leaning towards a High Volume.....

I'm no pro at rebuilding engines, but I've done my fair share. I'm also not a fan of high pressure pumps. I personally would not add a high pressure pump to an old engine with a new head or not. Heck, I'm not a fan of installing a rebuilt, or new head on a old short block. Think about it. Higher than normal pressure with 170,000 mile main seals trying to keep the oil in the engine where it belongs.
If I were to do it (and I'm not), I'd do high volume. In my opinion (and there will be many), more volume is much better than high pressire. If you have low pressure you have other problems that need addressed. At that mileage chances are that your bearings aren't the best. Adding a new head creates more compression wich puts more stress on the low end.
THAT'S MY OPINION. Good luck though. Hope you get it worked out.

Honestly It runs GREAT Has good compression I had no choice on the Head swap because it was cracked in 2 chambers.........im sure the bearings have extra clearence but i would rather put a HV oil pump in it than try to half ass it and do a In-frame and swap bearings..........

98 jeepjeep said:

Engine was NEVER rebuilt...

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Oops, my fault. I re-read your original post and realise now that I got that part wrong.

I have a Cracked Head and Removed it and also Replaced the Loud lifters

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Okay, much clearer. Just off the top of my head, since it sounds like oil's not making it all the way to the top of the engine: have you replaced the oil filter and checked the pump (there's a screen in the pickup IIRC) for blockages? How sludged-are the undersides of the valve cover and oil pan? May be worth running some Seafoam or similar through the crankcase on the off-chance that there's crud gumming things up, and taking some brake cleaner to the valve cover & oil pan.

If that doesn't do it, I'd check that oil's getting to the rockers (which could be a function of sludging) and that the rockers were installed to spec. From there I'd start suspecting the oil pump... And if that doesn't do it, the oil passages themselves. Everything lined up OK when the new head went on, including where the gasket sits between the head and block? No RTV or similar ended up blocking flowholes?

.......Oil pressure Use to read 20psi at idle and around 40 Cruise...HOT But i snapped that Original Sender off during the head swap and replaced it with a GP Sorcen From Advance Auto which Reads 35-40 at idle and 50-60 Cruise...which i know isnt RIGHT...However i Have not put a Mechanical Guage on it...

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Fair enough. 20/40 idle/cruise when warm is within spec, so we'll go with those numbers for now. No gauge makes figuring it out a little harder, but we'll go with what we've got.

But from my experiance with Hydraulic lifter they get Noisy when worn or pressure is low.

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*Nod*. Been there, done that, had the tappet noise to prove it

These were new lifters, right? And the springs, etc. - were those replaced at the same time?

I completely understand what you are doing and why. I've had to do quick fixes to get me by before. If you have to, I'd go with HV pump, but I'd start saving for a complete rebuild.
Dang jeeps anyways. It seem like a guy never stops working on them. lol

Well im about to order my RC 6.5" long arm kit so a Rebuild isnt high on the list since it runs so good........Im a Mechanic by trade so things like ticks and suck drive me crazy. However When i took the top half of the engine apart it was as clean as a whistle! so no sludge...everything lined up..lifters are new. they are not as loud as the 170k ones that came out of it..........When i pull the oil fill cap off the VC the rockers are full with oil......

I don't think 20psi hot idle is bad, nor do I think 40psi at hot cruise is bad, for a stock 4.0l.
So I'm not sure what you want to cure?? You install a high volume pump, and by definition, your oil pressure should go up. Whether oil pressure in excess of what you have will help noisy lifters, is another story--I don't think so.

http://www.aa1car.com/library/2005/us020516.htm

Thats a good site for some basic reading on a oil pump....and as mentioned the oil pump is the ONLY thing that gets UNFILTERED oil so if it isnt chaged on time(like many people with SUV'S do) it can wear rather quickly........and one shouldnt directly point fingers at worn bearings.........unless of course the OP was already replaced.

98 jeepjeep said:

Well im about to order my RC 6.5" long arm kit so a Rebuild isnt high on the list since it runs so good........Im a Mechanic by trade so things like ticks and suck drive me crazy.

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I hear ya. Not a mechanic here, but I get where you're coming from.

However When i took the top half of the engine apart it was as clean as a whistle! so no sludge...everything lined up..lifters are new. they are not as loud as the 170k ones that came out of it..........When i pull the oil fill cap off the VC the rockers are full with oil......

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Ok, those are good signs. At this point I'd change the filter for a completely different one, and if that doesn't cure it, Seafoam it then drop the pan and inspect things in there. It'll mean yet another oil change, but at least it rules out some possibilities in that area. I'm kinda leaning towards a possible blocked pickup or weak oil pump at this point, but don't want to call that one just yet. The 20/40psi idle/running pressure sounds about right, and is giving me cause to think the issue could possibly be elsewhere.

Out of curiosity: any oil soak on the air filter?

casm said:

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Out of curiosity: any oil soak on the air filter?

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Nope not at all!! blowby tubes are dry and clean.!! and removing the oil cap with it running there are NO blowby vapors to be seen in the rocker galley......Im thinking a worn pump also....but since it needs a new RMS im thinking what the heck ill replace the pump anyway...if it fixes it kool if not ooh well ill still bog it!!

Im using the MotorCraft FL-1 Oil filter.

That oil pressure reading doesn't seem too far off. Perhaps the old one was leaking pressure and the new one obviously is not...so.....

If you replaced the all the lifters with new units, and you had and still have good oil pressure then on a engine with 170k you should look at the rocker arms and pivots. when you took the old head off did you keep all the rocker arms and pivots in exact order? if you mixed them up that will cause a problem on old worn parts ans they have a pattern... BUT the parts if never replaced are worn to the point they will make noise. clatter or ticking,ect. buy all new rockers and pivots..and get some new push rods also. you can get all these parts from rockauto.com very reasonable and that is what my guess is your noise. as for the oil pump I replaced the factory pump on my engine at 175K along with all new lifters rockers pivots and push rods..my rockers were shot. and I used the melling hivol pump. my engine as over 230k now and is still quite as can be. I support the HiVol pump

I made sure i checked the Rockers and Pedstals for wear...they were smooth as can be..Rockers,pedestals,pushrods were all cleaned and inspected at the machine shop. So your jeep had the lifter chatter and once you repaced all that and put in a HIVOL pump its quite now?

98 jeepjeep said:

I made sure i checked the Rockers and Pedstals for wear...they were smooth as can be..Rockers,pedestals,pushrods were all cleaned and inspected at the machine shop. So your jeep had the lifter chatter and once you repaced all that and put in a HIVOL pump its quite now?

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correct..but my rockers were shot, very loose when i inspected them on the engine.

ya my rockers are quite...i wish it was that simple.....

I'd vote for Hi Vol. I put one in due to somewhat low oil pressure (40psi cold, 20-25psi hot highway, 5-10psi hot idle) and it quieted her down somewhat. Be warned, however, that you'll have to beat the &*(& out of the oil pan to fit the Melling Hi Vol pump. It's about 1/2" longer than stock and the pan won't fit on the block.

thats fine...i have a vast selection of BFH'S