Oil issues

[Timmaay]

Background:

Truck is an 89 4.0 AW4 with 126,000 miles

I recently changed the oil in my truck to Rotella T 15w-40 and a NAPA 1626 Gold filter. I changed the oil because my engine seemed a little noisy compared to my friends 4.0. I suspect lifters or rocker arms or something around that area. I am far from an expert but it definitely seems to be coming from the top end. With the oil changed the truck seems a bit quieter but not where I'd like it to be.

 

The Problems:

Upon cold start up it now sounds like it is not getting oil for a second or two. Sounds like a loud CHUH CHUH. What do you guys think? The temperature around here never gets below freezing so I thought 15w40 would be fine?

 

The oil pressure gauge also reads pretty high. Like 70 or so at a cold idle and then down to 40 at a warm idle. The guage will go up to 80 when I first start driving after a cold start. I don't have a mechanical gauge to check the accuracy.

[Pete M]

do you know what oil you had in before?

 

Maybe your filter isn't retaining oil like it's supposed to?

[Timmaay]

No I don't know which oil was in there before. This is the first oil change I have given it since I bought it.

 

What are the chances that the oil filter is faulty? :hmm: Should I go out and try a different one?

[87Warrior]

Does your oil meet or exceed the AECA A1/A5 or A3 specification? Had a big discussion about that a few months back. Top half of the 4.0 is like an airplane motor, have to keep it lubed.

 

I would personally stick with the 10w-30 oils. The NAPA filter is probably fine.

[Timmaay]

From the back of the jug: Meets API service CJ-4, CI-4 Plus, CH-4, CG-4, CF-4, CF/SM

 

Meets the performance requirements of ACEA E9, Mack EO-O Premium Plus, Caterpillar ECF-3, ECF-2, ECF-1A, Cummins CES 20081, DDC 93K218, MB Approval 228.31, MAN 3275, MTI cat 2, Volvo VDS-4, Deutz Dqc III-05, JASO MA

[Timmaay]

I should have mentioned hat the oil pressure used to read fairly high, now it is a bit higher.

[87Warrior]

Whoops, I meant ACEA.

 

I am far from an expert, but it looks like you are running something designed for an oil burner.

[Eagle]

I wouldn't worry. If the oil pressure was high (i.e. good) before, going to a heavier oil would logically result in higher pressures. Since the factory spec used to be 10W30, you can probably assume that's what was in it. So a quality 15W40 should be expected to be a bit higher across the board.

 

FWIW, the factory oil pressure spec is 13 psi minimum (no maximum stated) at idle, and 37 to 75 psi above 1600 RPM. Most of the XJ/MJ engines produced around 66 psi at highway speed on 10W30 oil when new. 40 weight would produce more. But engines have tolerances, and it's possible you have a nice, tight one that doesn't suffer oil pressure problems.

[Timmaay]

Thanks for the info Eagle. I won't worry about the oil pressure then.

 

What I am still worried about is the noise at cold start up. I talked to my uncle about it and he suggested that it may be a leaky or sticky lifter. Does that sound reasonable?

 

I don't drive this truck all that much and when I do do it's only short trips. Could that be a contributing factor?

[Oizarod115]

4.0L is generally a noisy motor, you're going to have piston slap on a cold start up, as long as it goes away with some temperature and it's not a horrible noise don't worry about it.

 

some of them are quiet, some of them made noise out of the box

[ParadiseMJ]

The pressure in my XJ has always run high, mechanical gauge, stock gauge, say the same. At or just below mid point at idle, halfway twixt half and pegged at 60 mph.

 

My MJ runs lower, both run Castrol Full Synthetic 10w30. Rotella's fine but the synthetic worked so well in the XJ I swapped over all my vehicles. I was told a NAPA Gold is a WIX filter, you're good there.

 

XJ, MJ, Ranger, Camry

[Eagle]

The pressure in my XJ has always run high, mechanical gauge, stock gauge, say the same. At or just below mid point at idle, halfway twixt half and pegged at 60 mph.

I apologize up front, but this bugs me. Those gauges have numbers so the actual oil pressure can be read and discussed. What's the point of saying "mid-point" when there's a mark at the mid-point and the number 40? Halfway from the mid-point to pegged is 60 psi -- which isn't exceptionally high considering that most XJs and MJs (other than those with problems) typically run about 55 psi at highway speed.

 

Why not just report the number?

 

Curiously, I've noticed that people on this board routinely report temperature readings as actual numbers, when there is no way on this Earth they could get those numbers from the temp gauge. The oil pressure gauge is calibrated linearly. The temp gauge is not. And the temp gauge only has three numbers on it. On the temp gauge, it WOULD be appropriate to report "halfway between 100 and 210," because I don't think anyone knows what actual temperature that position on the dial represents.

 

Why are we ignoring numbers that mean something, but reporting numbers that can't possibly be accurate or correct? I don't get it.

[Randy in Maine]

Excellent point well taken Eagle.

 

Also make sure that the electrical connection is good on the wire that goes to the sender. I never use teflon tape on the senders as it can interfere with the grounds for the sender. If you feel the need to use teflon tape, just run a new ground wire to the sender unit.