Worn Engine

[JNo]

I have a wrangler with the 2.5L 4cyl. The engine runs a low oil pressure. At idle it goes to zero. I'm currently saving to have the motor rebuilt, but for the time being I would like to make the engine last as long as possible. My question is would it be better to run a thicker oil (15w-40 or 20w-50), or continue to run my Pennzoil Conventional 10w30?

After I talked to a local mechanic, he mentioned adding LOS to a thick oil to help with the bearings. Is there any truth to the theory that Lucas will help with the bearings? Any advice is appreciated.

 

[jorton]

Yea, Pennzoil Conventional 10w30 is resource conserving oil, so it gets pretty thin with use. One step thicker is HD30. Two steps thicker is 10w-40. Three steps thicker is 15w40 and that is thick oil.

Folks who use LOS say they like it. Others who have never used it say they don't like it. Good luck!

 

[Brons2]

The Jeep motors are known to do well on xw40. I would try 15w40 and see if that gets your oil pressure up some, 15psi at idle would be a lot better than 0.

Normally I'd recommend 5w40, but that stuff is more expensive. Supertech 15w40 is cheap.

 

[IndyIan]

Maybe adding alot of moly additive would help? Its claim to fame is providing lubrication when the oil is missing from a bearing.
I'd go to HDEO 15W40 as well, but I don't have any experience trying to keep an engine limping along, I just run it in my Neon for track duty to keep it from getting as bad as your engine.

 

[Since1941]

Maybe Shell Rotella T 10w30?

 

[bodeh6]

Try Quaker State Defy 10w30

 

[expat]

You have come to terms with the fact ' you are on borrowed time' So why are you reluctant to use a thicker oil to bring your oil pressure to an acceptable level?

I'd jump in with a 15 w-40 or 20 w-50 or add a bottle of STP or other Thick additive to what you have, to keep the mill running.

 

[tomcat27]

How many miles? I, too, wore out the bearings on a Jeep motor - albeit the 4.0. The shop rebuilt my actual motor. I was very happy with the results. yes, I would run a 15w40

 

[JNo]

Sorry, it's a '99 with 155,000 miles

 

[dishdude]

I'd run the cheapest 20w-50 I could find, especially considering where you live.

 

[wheelman]

155,000 and its wore out? Was it not treated well?

 

[aquariuscsm]

BuickGN ran VR1 SAE60 in a motor that had bearing knock,and it made it last till he rebuilt it.

 

[mongo161]

IMO....NAPA auto parts has Valvoline, Super Blue, 15w40 on sale right now at their stores. You could pick up a couple of Jugs for $12.99 each or go to Walmart and pick up the SuperTech 15w40 for around the same price. Advance Discount Auto has Shell Rotella, 15w40, on sale for 12.99 a gallon.

Just take your pick.....

 

[tommygunn]

Thirding, or fourthing the 15w40

 

[crazyoildude]

Could it be the oil sender is bad or clogged up?
I remember having a number of bad oil senders even some new ones..

 

[wally6934]

If you know the oil and filter history of this jeep it would be nice if you posted it so we could all learn something. 150K miles is much to short for an engine to wear out, maybe you could help one of us avoid the same problem.

 

[Trvlr500]

30+ years ago I had a '68 AMX. The engine started going on a 600 mile road trip from Southern California to Tuscon, AZ. I started with straight 40wt and ended up running 70wt in it on the drive home. We went through a LOT of oil on that trip. 2 or 3 cases of it. There was clean oil dripping from the exhaust pipes it was in such bad shape. At 80mph the oil pressure gauge was reading about 10 or 20 psi if I remember correctly.

Why mess around. Put a straight 40wt in it and if that doesn't get the pressure up step up to 50wt or add a can of STP to the 40wt so you don't have to change it again. You're in AR and summer is just about here. You don't have to worry about real cold starts. If you have 0 oil pressure at idle and the sender isn't defective 15-40 or 20-50 is too thin. Mono grades are cheaper as well.

 

[Zaedock]

Originally Posted By: JNo
Sorry, it's a '99 with 155,000 miles


I would add a mechanical gauge to verify the actual oil pressure. The Jeep factory sending units leave a lot to be desired.

If you do in fact, have 0 oil pressure, replace your oil pump. I'm a Jeep guy - have 2.5L and 4.0L rigs, a 4.0L buggy, and work on friends Heeps. In my experience, the average factory pump life is about your mileage. Also, IMO, the factory Jeep upper oiling has never been super. I usually add a high volume pump with either a rebuild or replacement but the stock volume replacement usually cures the Jeep "tick", other noises, and low pressure. Currently building a 4.0L Renix for my kid's Cherokee and will be adding a Melling HV pump.

If memory serves, the standard volume Melling pump you need is an M-81A. For $60 or $70 and a new oil pan gasket (get the Felpro one piece rubber with steel inserts) is worth a try.

 

[A_Harman]

If you have been running the engine with zero oil pressure, it's probably toast. I'm picturing bearings pounded into shiny Wheaties. Zaedock's advice sounds good to me. Put on a mechanical gauge and replace the oil pump. I would add drain the oil and check for pulverized bearing material. Cut the filter apart and look for bearing material there, too.

If you must keep driving it, put in 20w50, and see if it helps the oil pressure, but I think you're delaying the inevitable need to do some serious maintenance.

 

[OVERKILL]

Originally Posted By: Zaedock
If you do in fact, have 0 oil pressure, replace your oil pump. I'm a Jeep guy - have 2.5L and 4.0L rigs, a 4.0L buggy, and work on friends Heeps. In my experience, the average factory pump life is about your mileage. Also, IMO, the factory Jeep upper oiling has never been super. I usually add a high volume pump with either a rebuild or replacement but the stock volume replacement usually cures the Jeep "tick", other noises, and low pressure. Currently building a 4.0L Renix for my kid's Cherokee and will be adding a Melling HV pump.

If memory serves, the standard volume Melling pump you need is an M-81A. For $60 or $70 and a new oil pan gasket (get the Felpro one piece rubber with steel inserts) is worth a try.



Are you serious? That's some pretty awful pump life IMHO for an engine that is so oft touted as "bulletproof"......