99Justin4.0

Hey, I gotta clicking WJ. Got the good ole Mystery Tick/Knock. I'm pulling the oil pan to look for damage or piston slap.

Afterward I'm switching my Oil to Rotella T6 5W40. I already bought the oil, so no arguments on that please.

My question for any experience Jeeper is: Is there any specific Filter that handles the heavier oil better?

I'm thinking Mopar, but Rotella makes them too. The Rotella has all that extra diesel oil stuff in it, maybe it needs the Rotella filter that's designed specifically for it???

I already know NOT TO USE FRAM!!!

dave1123

I would think any good filter would work. I used to use nothing but AC on my Chevys. They worked well with 40 weight racing oil. The problem with Fram is they used to use poor paper for the filter media that would collapse when it got the slightest bit clogged. I grew up near the Fram plant in Cranston, RI and they just about gave them away. When the paper collapsed, most of the oil went thru the bypass valve.

A diesel filter has to deal with all that carbon contamination that you won't find in your 4.0.

Nick-B

Don't over think it Justin, any good filter will do just fine and handle the slightly heavier oil without issue.

Fred/N0AZZ

Use Wix or NAPA Gold (made by WIX) you will have the best filters made, take it from someone who has cut open hundreds of them for all my cars and race cars after every race weekend. Then you will see the difference between the filters and how well they filter, it's what's inside that counts.


Keep in mind that your 99 4.0 had the bad head on it from the factory.

dave1123

Good point, Fred! Keep a close eye on your coolant level. A sudden loss of substantial coolant without visible leaks is a warning sign of a cracked 0331 head. Check your oil frequently for signs of coolant contamination. There is plenty of information on this forum about this problem. Check it out.

99Justin4.0

Already found the problem. Broken piston. Already half way to having new ones in. Luckily my cylinder wall was okay.

I'm pretty sure my head is good. I'm having it checked either way.

When all is put back together, I'm wondering if I should even use the Rotella... New pistons and rings might do better with 5w30.

dave1123

I'm telling you man, as long as it's already apart, if it's a 0331 head TRASH IT! It's a ticking time bomb at best! That's my opinion based on personal experience. I caught mine in time to save the bearings. 200K miles on it and still 40 psi oil pressure at idle hot!

99Justin4.0

Mine ran perfect and was 42 psi at running temp idle. About 45 under load. Just made that damn noise.

Honestly if this wasn't my only vehicle, had time to let it sit, and I had the extra $500+ to spend I would.

My ultimate plan is to buy an engine that I completely rebuild to have ready for later. But at the moment I can only afford what's absolutely necessary.

I'm pretty used to doing major engine work. I was in to 89 and earlier VW and Porsche's before and had to do swaps and transmissions all the time. I had the engines out like twice a year. You get pretty quick. These Jeeps are easier to work on, so I'm counting on getting dirty as much as I need to.

I see a lot of your past posts when I google stuff Dave, and value your opinion from what I've read. It's just a matter of time and money at the moment. I gotta get back on the road asap.

My head guy will be checking it out though. And I'll make damn sure I don't get it too hot or over revved.

BTW: I am interested to know where to find a reasonably priced TUPY.

Fred/N0AZZ

Your not just installing a new piston/rings into the cyd. where the broken one was are you?

99Justin4.0

No.

PS: If any of you serious gear heads want to see why I'm pretty fearless when it comes to these Jeep engines, look up:

Porsche 944S 16V broken timing belt.

If I can live through that, I can live through anything...

Fred/N0AZZ

Yes you be the man

Cleman Simpson

Not to hijack this thread but what's the deal with that particular head and what year models/engines was it stock on?

NewbJeep

Bad casting right from the factory

dave1123

99-01 4.0 XJs and WJs. Probably Wranglers too. Chrysler says any cracking is due to poor maintenance, but we all know that's BS! They "improved" the valve port design for better flow, creating weak spots in the head. They usually crack between #3 and #4 cylinders. Shine a strong light down the oil filler cap hole and you may see a crack between the 2 center valves with coolant leaking out. You may also see "0331" cast into the metal.

Chrysler "corrected" a problem that officially didn't exist with the 02 production year with the "TUPY" head, an 0331 cast in Brazil with nickel in the mix. Some early 02s might still have leftover 01s however. TUPY is the name of the foundry that produced them.