• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

reman engine low oil pressure

toates89

toates89

NAXJA Forum User
Location
suffolk
So i just had reman 4.0l engine installed in my 99 WJ(same engine) after the first engine threw a piston at 115k.

the new engine's oil pressure drops to 10 at idle after highway driving, and sometimes down to 0.

I changed out the sender for a new one, and i also changed oil filters. neither fixxed the issue.


There is no ticking and it seems to be running fine.

Could the new engine oil pump be no good?

its a crate engine from marhsall engines, also has the tupy head.

everyone keeps on saying go heavier on the oil but i am not trying to bandaid a brand new engine.

What is everyone elses opinion on the matter.
 
Just verify pressure with a manual gauge. If its still low have them warranty the engine. If its new i wouldnt settle for a pump swap.
 
Ask the reman people what rocker arms they used. Some rockers have oil holes that are too big and will cause low oil pressure, if used with standard pushrods. Seems odd but it happens.
 
slk88xj said:
Just verify pressure with a manual gauge. If its still low have them warranty the engine. If its new i wouldnt settle for a pump swap.
Click to expand...

Do that.
 
What oil are you using, specs?

How many miles on it?

Did you use a break in oil, and what brand oil filter is on it?

Did you reuse the old oil pressure sender or?
 
5w30 valvoline

50miles

first was a fram i pulled it and now its stp oil filter

yes and replaced it with a new one
 
Verify. With a mechanical gauge. They can be rented very inexpensively from many parts stores.

Unless you do this, there is a chance that you are chasing your tail............

Good data = good decisions.
 
toates89 said:
5w30 valvoline

50miles

first was a fram i pulled it and now its stp oil filter

yes and replaced it with a new one
Click to expand...

OK, so two oil senders, and no change in the dash pressure?

Is it using oil at all? History of oil use? If yes, try 15-40 or 20w50.

If the oil was new, with no pressure at idle, I would not suspect gasoline dilution, leaking fuel injector, but keep in mind that can cause the low pressure, so can antifreeze leakage into the oil, but it sounds like you have ruled those out here?

I use 20w50 on all my vehicles. Also there is a thread here somewhere from last year where a guy discovered that the feed line to the pressure sensor was blocked. He pulled the valve cover and at idle there was plenty of oil top side, and he came up with a way to clear the blockage to the sensor (cranked the engine with the sensor disconnected, removed?). Cruiser54, do you recall that? I think you even tried it and helped yours too?
 
Last edited:
It is a re manufactured engine with 50 miles so i doubt there is any sludge. i also live in NY so using 20 50 would cause serious start up problems. i used to get lots of ticking in the am with 10 30.

There is indeed only 10 psi at idle and the engine only has 50 miles on it. the shop is going to drop the pan, check the pump, screen, and pull the caps and check the bearings.
 
toates89 said:
It is a re manufactured engine with 50 miles so i doubt there is any sludge. i also live in NY so using 20 50 would cause serious start up problems. i used to get lots of ticking in the am with 10 30.

There is indeed only 10 psi at idle and the engine only has 50 miles on it. the shop is going to drop the pan, check the pump, screen, and pull the caps and check the bearings.
Click to expand...

I hope you used a high ZDDP content break in oil then.

Sounds the rebuilder did something wrong if a mechanical gauge confirms the low pressure.
 
13 psi is the low limit from the factory. If it doesn't hold that with 10w30 then demand another engine.
 
Sounds like a defective rebuild. Cam bearings are a problem on the 4.0. If you checked pressure with a mechanical gauge & it confirms low pressure you are up for a replacement engine.
 
well we plastigaged the mains and connecting rod bearings.

CR's were good

Mains we at .003 so i am going to see where we go form here
 
Ecomike said:
You the man Cruiser!!!!:wave1: I wonder if Joe has seen that one yet?
Click to expand...

I hadn't seen that, but used to have a similar issue with a well pump and holding tank. The holding tank had a pressure gauge on it, and the end of the gauge would fill up with c*ap and the pump wouldn't run--no shower water in the AM and I'm out in the garage in my birthday suit pulling the gauge and shoving a piece of bailing wire down the hole while cussing a blue streak--not a pretty sight!
 
joe_peters said:
I hadn't seen that, but used to have a similar issue with a well pump and holding tank. The holding tank had a pressure gauge on it, and the end of the gauge would fill up with c*ap and the pump wouldn't run--no shower water in the AM and I'm out in the garage in my birthday suit pulling the gauge and shoving a piece of bailing wire down the hole while cussing a blue streak--not a pretty sight![/QUOTE]

No pun intended?
Click to expand...
 
cruiser54 said:
joe_peters said:
I hadn't seen that, but used to have a similar issue with a well pump and holding tank. The holding tank had a pressure gauge on it, and the end of the gauge would fill up with c*ap and the pump wouldn't run--no shower water in the AM and I'm out in the garage in my birthday suit pulling the gauge and shoving a piece of bailing wire down the hole while cussing a blue streak--not a pretty sight![/QUOTE]

No pun intended?
Click to expand...

Well, beauty is in the eye of the beholder...
Click to expand...
 
You must log in or register to reply here.

Similar threads

M
Oil pressure question
2
Replies
26
Views
3K
Money_Pit_Incoming
M
H
Oil pressure sender 98 vs 99
Replies
14
Views
2K
hbar..
H
A
00 XJ - Low oil pressure at hot idle. Compression and analysis are good, what's next?
Replies
12
Views
2K
sixditchoffroad
sixditchoffroad
C
Oil Pressure Sender Woes
Replies
3
Views
907
RCP Phx
R
A
Oil pressure issue
Replies
2
Views
1K
cruiser54
C
Back
Top