Oil Suggestion- 2000 Jeep Cherokee

[jls095]

I have a 2000 Jeep XJ (Cherokee) with the 4.0. It has been in my family since the beginning, first with my dad and then with me when I got my license. It has 75,000 miles and runs perfectly. I decided that I wanted to run synthetic oil in it, so for the past two changes I’ve used 10w-30 (the recommended weight) Mobil1 Extended Performance. Ever since the switch I’ve noticed a piston slap (“chattering” noise) at start-up that eventually goes away. This isn’t an all that uncommon occurrence in the 4.0, but if it wasn’t there before the M1 I want to see if there’s something I can switch to that gets rid of it. I don’t know what type of oil was in it before I used M1 because it was done at a shop.

Some other info: I primarily use the Jeep as a daily driver, but I do off-road it on occasion. I live in NJ where the temp never goes below 0*. My typical trip is less than 5 miles, and I drive it easily. I change the oil yearly or after about 7-8K miles, whichever comes sooner.

On a separate note, I’ve noticed that a considerable amount of Jeep owners run oils like Rotella T6 or Mobil Delvac in their engines because they have more ZDDP (4.0’s are flat tappet). I would be open to this, but I’d really like to stay synthetic and Mobil Delvac 1 and Rotella T6 are 5W-40 (rather than 10w-30, which I’ve been running).

Any suggestions/advice would be great.

 

[gomes512]

Yep all the Jeep guys worry about the "lack" of ZDDP in current oils. Thinking their 4.0's will grind down to dust. But the HDEO's that mentioned are great oils.

The truth is these engines don't use high spring pressures. The ZDDP issue is relevant to high performance cam setups. The proof is on the streets.

I have noticed the slap you describe with certain 5w-30's in my 4.0. I'm currently running a fill of PYB 5w-30 that does the same. Goes away after 3-5 minutes after driving. Seems to be temp dependent. It started at 65K, currently at 155K with no problems.


BTW I'd check your exhaust manifold closely. A common problem with the 4.0's. Long hairline cracks that run parallel with the tubes. They close up after a couple of minutes of running from the heat. When cold they allow the exhaust to escape slightly. Makes a piston slap type noise, replaced them on 3 seperate XJ's.

 

[Hollow]

T6 is well regarded in those engines, and it'll run fine switching from 10w30 to 5w40.

 

[aztec12]

I had a couple of grand cherokees 4.0 and they did great on maxlife 10w30 with no oil usage at all.This oil is good at least 5k intervals or every 6 months.

 

[jls095]

This is going to seem crazy but here goes. If I run the 5w-40, which from what I understand is thicker than 10w-30 at operating temps, will it expand clearances in the engine? Meaning to say, if I switch back to 10w-30, will my oil pressure be the same as it is now?

 

[bodeh6]

You should try some German Castrol (aka Syntec 0W-30)

 

[KW]

Originally Posted By: jls095
This is going to seem crazy but here goes. If I run the 5w-40, which from what I understand is thicker than 10w-30 at operating temps, will it expand clearances in the engine? Meaning to say, if I switch back to 10w-30, will my oil pressure be the same as it is now?


Running a thicker oil won't expand the clearances -- it will be just fine. I have a '98 Cherokee with a 4.0 and I ran Mobil 1 0W40 for a few oil changes and I really liked the way that oil worked in it. It's a thinner 40 weight. But for the past 10 or so years I have used Amsoil 10W40 in it because I keep cases of the stuff in my shop for other equipment.

 

[Toto]

Originally Posted By: jls095
I have a 2000 Jeep XJ (Cherokee) with the 4.0. It has been in my family since the beginning, first with my dad and then with me when I got my license. It has 75,000 miles and runs perfectly. I decided that I wanted to run synthetic oil in it, so for the past two changes I’ve used 10w-30 (the recommended weight) Mobil1 Extended Performance. Ever since the switch I’ve noticed a piston slap (“chattering” noise) at start-up that eventually goes away. This isn’t an all that uncommon occurrence in the 4.0, but if it wasn’t there before the M1 I want to see if there’s something I can switch to that gets rid of it. I don’t know what type of oil was in it before I used M1 because it was done at a shop.

Some other info: I primarily use the Jeep as a daily driver, but I do off-road it on occasion. I live in NJ where the temp never goes below 0*. My typical trip is less than 5 miles, and I drive it easily. I change the oil yearly or after about 7-8K miles, whichever comes sooner.

On a separate note, I’ve noticed that a considerable amount of Jeep owners run oils like Rotella T6 or Mobil Delvac in their engines because they have more ZDDP (4.0’s are flat tappet). I would be open to this, but I’d really like to stay synthetic and Mobil Delvac 1 and Rotella T6 are 5W-40 (rather than 10w-30, which I’ve been running).

Any suggestions/advice would be great.


My Family has the same vehicle, used Mobil Dino for years was happy with it started leaking oil a little and ran HM Pennzoil for a year was happy with that also, last oil change used AMSOIL OE it is leaking going to use Super Mobil HM at next oil change, in my opinion stay with 10W 30 I am a believer in using the recommended oil, this has been a very good and reliable vehicle, if you insist on synthetic try Valvoline HM Synthetic it is SN rated Mobil 1 HM is not.

Toto.

 

[ARMY_Guy]

I have that 4.0 in the Jeep.
Mobil 1 TDT is 5-40; and will work very very well in your engine. Goodluck.

-A

 

[dgee]

I'm currently running Delvac 15W40 in my 4.0's
Both my GC's sound good and run well so I'm happy.

Don't worry about the ZDDP or flat tappet nonsense. I run 40 weights because:
1) the car sounds quieter. 2) slows down consumption on my 94 GC going on 320k miles

 

[rslifkin]

My mom's 99 GC 4.0 lived on whatever dino 10W-30 for the first 90k or so, and it's been on 5W-40 Rotella T6 since then. Runs like a champ. Her old 95 GC 4.0 was running great when she sold it at 110k, and it just had whatever 10W-30 dino as well.

The extra ZDDP in an HDEO certainly doesn't hurt, but once a 4.0 is broken in, even though they're flat tappet cams, the spring pressure are low, etc, so they don't need a fancy oil. They do like 40 weights though.

 

[Eddie]

My 95 GGC with the 4.0 was run on Mobil1 10w30 & PureOne filters through out the 197,000 miles I had it. I sold it to a neighbor who eventually moved away. Last I heard it had over 230,000 miles on it and going good. OCI was 6-7,000 miles. Only problems ware a rear main seal, a valve cover gasket, 2 WPs and one Alternator.

 

[caravanmike]

in my 99 xj cherokee 4.0L i run maxlife 10w-40 year round.

 

[FL_Rob]

Since you stated that your oci is one year or 7/8k miles and your typical trip is less than 5mi,your fuel dilution is probably off the chart,which could explain the extra cold start noise.The oil will never burn off condensates or gas dilution even with running synthetic.I recommend cutting the oci to 6mo. and taking mileage out of the equation for the fact your short trips are killin' the oil over the entire year.

 

[rslifkin]

^ Agreed. 4.0s take a while to get the oil good and hot. With my mom's 3 mile commute, I won't let hers over a 5k OCI, even though she usually drives it longer on the weekends and such. If I pull the dipstick on a Thursday or Friday, it usually smells a bit like gas.

 

[jls095]

Originally Posted By: FL_Rob
Since you stated that your oci is one year or 7/8k miles and your typical trip is less than 5mi,your fuel dilution is probably off the chart,which could explain the extra cold start noise.The oil will never burn off condensates or gas dilution even with running synthetic.I recommend cutting the oci to 6mo. and taking mileage out of the equation for the fact your short trips are killin' the oil over the entire year.

I will certainly take your advice on shortening the OCI. That said, the "noise" started the first time I started it after putting M1 10-30 in it.

 

[bustednutz]

I bought a 98 XJ with 75k miles. I used 5w30 Mobil 1 oil for 40k miles and never a single problem. It cleaned up the internals incredibly as well. I traded it when gas prices went sky high a few years back. That was an incredible vehicle. One of my all time favorites.
I'd recommend the Mobil 1 just from my own personal experience with this vehicle.

 

[oggb]

I'd try another brand of filter and see if the clatter goes away. Might be a faulty ADBV if these engines require a filter with one.

 

[rslifkin]

FWIW, some 4.0s are just noisy (mild piston slap, little bit of valvetrain noise, etc). It's not necessarily a problem, and they all sound a bit different.

 

[jls095]

Well I've decided that I would prefer to stay with a 10w-30 AND that I want the added ZDDP in a HDEO...that said...does Rotella T5 (synthetic blend) sound like a good choice? I haven't heard much about this oil, but what's the consensus?