HELP! No oil pressure on startup

Vehicle is a 95 XJ Country, and the engine is BRAND NEW (less than 3k miles). It runs perfect except the first start of the morning, after it's sat overnight. taps and rattles a LOT on the AM start and takes a good 30 sec to build oil pressure, and only builds to 20psi. Drive it a little, and she posts 60psi cold and 40-45ish warm at 2000rpm or higher.

Something is obviously causing the oiling system to lose it's "prime" overnight and has to reprime itself in the morning. Here's what I've come to as possible culprits...

Oil Pump - drainback isn't holding the oil after shutdown
Bad Lifter - not staying pumped up, allowing the oil to drain down
Bad Main Bearing - yeah, we all know what that means....

Anything else I should check first before I pull this engine and go off like a nuke on the engine manufacturer? This has me so stressed guys, I'm about to snap. I'm not a wealthy kid, and certainly can't afford $1000 for labor a second time around. Any help is appreciated.

~Erik

Get the engine mfg involved RIGHT NOW--The engine installer on notice next.You can change the oil filter to a Quality filter mfg, Not anything orange--.verify that the correct amount of oil is in the engine and the correct wt.
At 3000 miles it is due for a change anyway.

Wayne

Quality is my middle name, AmsOil filter, Mobil 1 10w30 high mileage (need the older API SL spec oil and not newer SM for this engine). Broke in for 500 miles w/conventional 10w30, otherwise M1 the entire time. I'm no ASE certified mechanic, but I do have an inclination for mechanical stuff, and I've never understood the quality vs cost argument. for me, it's quality every time.
~Erik

You sound like you know what you are doing. Even if it is a good brand oil filter, mistakes happen. I'd change that first.

Wayne Sihler said:

Get the engine mfg involved RIGHT NOW--The engine installer on notice next.

Click to expand...

X2 on this. They need to know ASAP, and they need to take care of this for you. The sooner you get them involved, the better covered you are if something goes wrong.

You may want to keep the oil filter and either check it yourself, or have it checked to see if there's any metal particles indicating abnormal wear. Hopefully no permanent damage has been done.

And keep us in the loop. I'm hoping it's a simple fix...

Replace the oil filter, especially if it is a FRAM.

Where did you buy this motor and what warranty did they give you?? Time for a phone call to the company that you bought the engine from and a discussion about how to move forward..

Don't go off on them though. That rarely yields good results. Calmly describe your situation. Give them an opportunity to respond and resolve this.

Get your hands on a "mechanical" oil pressure gauge. They can be rented from many parts stores. I'd get some exact oil pressure numbers so that you can tell the builder what they are when you call them. Having this information (confirmed by mechanical oil pressure gauge) will let them know that you're not a newbie or uninformed about internals. If you don't confirm these numbers and just give them numbers from the cluster gauge, that may be the first thing they ask you to do.

Change the oil filter NOW!

Most likely to be the problem and easy to fix. Use another brand. Fresh new filter (No fram.).

Get the builder and installer involved NOW.

Gotta go with Joe. Best thing to do. Don't run it.

Forgot to mention that I've already tried numerous oil filters. Wix, Mobil 1, Bosch, and Amsoil, and none have resolved the issue.

Most likely cause is a bad oil pump. But the builder should diagnose and rework. Leaking lifter or bad main bearing would not decrease start up oil pressure. Don't try to tell him what is wrong though. He is supposed to be the expert.

Re: HELP! No oil pressure on startup,c. ,c. .

Wayne Sihler said:

Get the engine mfg involved RIGHT NOW--The engine installer on notice next.You can change the oil filter to a Quality filter mfg, Not anything orange--.verify that the correct amount of oil is in the engine and the correct wt.
At 3000 miles it is due for a change anyway.

Wayne

Click to expand...

not trying to change the subject ! whats the deal with no fram ?

Since Fram started making their filters in China, their filters, at least on the 4.0L have a high failure rate. I have personally seen several engines where the Fram filter has caused low to no oil pressure. It appears that the internals must collapse and stop up the filter.

This thead is a year and a half old.