OK to use in older Jeep 4.0

[Kcoastie]

Good morning. So I've got a stockpile of about 15 quarts of M1 10w30 EP from the AAP sale they had a while back that I bought for an '06 Magnum we had. Well now I traded that in on a new Dodge Journey and part of the deal was free oil, filter and lube service for 3 years at Chrysler dealerships.

I've also got a 99 wrangler 4.0 with about 135k miles on it that I'm currently running an ARX clean cycle through. I plan on running a rinse phase, plus one more clean and rinse phase due to the mileage, all with dino. This engine has always had dino, never used synthetic in it once.

Would I be ok to use the M1 after the two clean and rinse phases with the ARX, or should I mix half dino/half M1 that I already have after that? Thanks for any help you guys can throw my way.

 

[Zaedock]

I think I might succumb to the tales of M1 and leaking in older engines and continue running dino. However, you are running a couple ARX intervals and there are only a couple of spots that would leak. The rear main, oil pan, and valve cover. If it does start leaking, at least they're simple to change, and relatively cheap. It would be a good myth buster.

With that, I say run it.

 

[astraelraen]

Originally Posted By: Kcoastie
part of the deal was free oil, filter and lube service for 3 years at Chrysler dealerships.


Keep your oil ready for the Journey, the dealer probably won't be there for the full 3 years.

ha... ha.... ha....

 

[mstrjon32]

What Zaedock said. You're not going to do any harm by running M1 in your 4.0, but IMO, it's more likely to leak out of the the usual places. That said, in time the rear main, oil filter adapter o-ring, and valve cover are going to start leaking if they haven't already anyway.

I'm waiting for warmer weather so I can replace all three of them on my '99 Cherokee 4.0 which runs just dino oil at whatever interval is convenient for me.

 

[440Magnum]

Originally Posted By: Kcoastie



Would I be ok to use the M1 after the two clean and rinse phases with the ARX, or should I mix half dino/half M1 that I already have after that? Thanks for any help you guys can throw my way.




If it were *my* 4.0, and I didn't have proof that it had a big sludge problem, I'd switch without doing any funky "clean and rinse" process. I would just do a quick oil change (maybe 1000 miles) after the first batch of M1, and then change the filter and add enough oil to make up what's lost in the filter every 1500 miles for a couple of times after that, then call it good.

As for leaks- I've never had any leaks that I could attribute to switching to synthetic even after years of running dino. Old engines tend to get some leaks, and I've simply never had one turn into a gusher or even speed up on synth. I switched my own 4.0 to Synthetic (Rotella T Synthetic 5w40) when I bought it, and it already had 126,000 miles of oils of unknown origin at Jiffy Lube (at least the previous owner changed it regularly, albeit with who-knows-what). No leaks after almost a year, other than the slight weep around the oil filter adaptor that 4.0s are notorious for developing regardless of oil type.


Be aware that a quirk of the 4.0 is that it *never* got a roller cam, so if you're afraid of low ZDDP, then M1 might not be the best choice. Personally, with a low-lift, light spring-pressure, mild cam like the 4.0 has I just wouldn't worry.

 

[rg200amp]

I would run the M1 in it.

M1 is a solid oil.

 

[FastSUV]

4.0 is prone to highe iron wear with some of the UOA I have seen on synthetics....I use blend in mine right now, but may switch to dino.

I believe this is because syn is thinner and the flat tappet engine just likes dino...

The PERFECT oil for a 4.0 w/135k would be Castrol GTX HM formula 10w30...or MaxLife. They have more ZDDP and will be a good protection oil for a flat tappet engine

 

[Zaedock]

Originally Posted By: FastSUV
4.0 is prone to highe iron wear with some of the UOA I have seen on synthetics....I use blend in mine right now, but may switch to dino.

I believe this is because syn is thinner and the flat tappet engine just likes dino...

The PERFECT oil for a 4.0 w/135k would be Castrol GTX HM formula 10w30...or MaxLife. They have more ZDDP and will be a good protection oil for a flat tappet engine


High iron is sometimes the result when running Mobil1, but not all syns. It certainly won't cause any perceived harm. Also, there are many syns that are thicker than their dino counterpart in the same weight. FWIW, I've found the ideal weight for my application is SAE30 or 10W40 (in spring/summer/fall).
There are millions of Jeep 2.5L and 4.0L engines running on your average SM rated oil with lower ZDDP levels too, as there are other wear additives besides ZDDP.

 

[mstrjon32]

Originally Posted By: FastSUV
4.0 is prone to highe iron wear with some of the UOA I have seen on synthetics....I use blend in mine right now, but may switch to dino.

I believe this is because syn is thinner and the flat tappet engine just likes dino...

The PERFECT oil for a 4.0 w/135k would be Castrol GTX HM formula 10w30...or MaxLife. They have more ZDDP and will be a good protection oil for a flat tappet engine


I'm running GTX HM 10w-30 in my 4.0 now, but I'm thinking about trying a 5w-40 or 10w-40 oil out on it. No scientific reason for doing so, but on some of the colder mornings we've had this winter I heard some serious metal-on-metal action (hence the 5w). When warmed up the valvetrain can be pretty noisy, particularly between 2000-3000 RPM (hence the desire to try -40).

 

[BigNick]

If you're planning on keeping the new Journey.... Bring the M1 to the dealer at every oil change and use it in the Journey! (I'm assuming it has the 3.5L V6 which specs 10w30 anyways - not sure about the other engines, but even so.. 10w30 synthetic could be used even if it specs 5w30 regular dino).

Have the dealer fill the empty M1 container(s) with their bulk oil they would've used anyways, and use that oil in the Wrangler! (sounds funny, but most dealers don't mind)

If you're not keeping the Journey, go ahead and use the M1 in the Wrangler. A friend of mine started using Q Synthetic in his 98 Jeep, about 100,000 miles (all previously with bulk dino oil), with no issues.

 

[rg200amp]

Originally Posted By: BigNick
If you're planning on keeping the new Journey.... Bring the M1 to the dealer at every oil change and use it in the Journey! (I'm assuming it has the 3.5L V6 which specs 10w30 anyways - not sure about the other engines, but even so.. 10w30 synthetic could be used even if it specs 5w30 regular dino).

Have the dealer fill the empty M1 container(s) with their bulk oil they would've used anyways, and use that oil in the Wrangler! (sounds funny, but most dealers don't mind)

If you're not keeping the Journey, go ahead and use the M1 in the Wrangler. A friend of mine started using Q Synthetic in his 98 Jeep, about 100,000 miles (all previously with bulk dino oil), with no issues.


Thats thinkin with your noodle!


Those 4.0s are so well built.

 

[sparkplug]

I don't see any problem but I've heard the 4.0's like a thick oil anyways.

 

[440Magnum]

Originally Posted By: mstrjon32


I'm running GTX HM 10w-30 in my 4.0 now, but I'm thinking about trying a 5w-40 or 10w-40 oil out on it. No scientific reason for doing so, but on some of the colder mornings we've had this winter I heard some serious metal-on-metal action (hence the 5w). When warmed up the valvetrain can be pretty noisy, particularly between 2000-3000 RPM (hence the desire to try -40).


I doubt that you're hearing anything actually "metal on metal." Its probably just typical 4.0 lifter noise before oil pressure comes up. That said, my 4.0 seems very happy on Rotella T Synthetic 5w40, but I really would prefer to run a 10w30. The hot oil pressure at speed went up from about 45 to nearly 50 PSI (admittedly this is with the notoriously inaccruate dashboard gauge, I really should install a mechanical) with the 5w40, which tells me that the thicker oil is flowing less volume out of the various clearance spaces in the engine (bearings, lifter bores, etc.) I'd rather have lower pressure and higher flow for better cooling and assured oiling under all conditions.

By modern standards the 4.0 is a noisy engine, but its extremely tough and well-designed. You can hear its lifters because of the cam profile and where the lifters are located plus the absolute utter and complete lack of sound-deadening features like modern engines have, such as plastic/metal sandwich oil pans and valve covers. That doesn't mean modern engines are any quieter inside, it just means you can't hear as much of the racket they're making ;-) Of course my other driver is a 440 built with short-skirt hypereutectic pistons fitted on the loose end of the tolerance range for longevity under high load- the 4.0 is silent by comparison ;-)

 

[Gary Allan]

Originally Posted By: FastSUV
4.0 is prone to highe iron wear with some of the UOA I have seen on synthetics....I use blend in mine right now, but may switch to dino.

I believe this is because syn is thinner and the flat tappet engine just likes dino...

The PERFECT oil for a 4.0 w/135k would be Castrol GTX HM formula 10w30...or MaxLife. They have more ZDDP and will be a good protection oil for a flat tappet engine


4.0/2.5 traditionally shed more Fe ..but it's not a given. Quite a few did well with dino 10w-30. Viscosity can, at times, reduce it. Some speculate that it's from the timing chain.

My best UOA was with Delvac 1 5w-40. I did run RTS in my 2.5 for back to back 13 month/9.xk intervals. The wear numbers weren't stellar ..but the oil held up well in semi-short(er) trip usage.

This/these engines aren't very refined ..but are durable beyond belief. They may clatter or tick a bit as they age, but the most frequent instance of "problems" are in chassis that are 20 years old and saw only winter plowing duty ..or summer camp duty. I don't think I've seen more than a handful of daily drivers having any issue of merit.

 

[Nickdfresh]

Originally Posted By: 440Magnum
...

As for leaks- I've never had any leaks that I could attribute to switching to synthetic even after years of running dino. Old engines tend to get some leaks, and I've simply never had one turn into a gusher or even speed up on synth. I switched my own 4.0 to Synthetic (Rotella T Synthetic 5w40) when I bought it, and it already had 126,000 miles of oils of unknown origin at Jiffy Lube (at least the previous owner changed it regularly, albeit with who-knows-what). No leaks after almost a year, other than the slight weep around the oil filter adaptor that 4.0s are notorious for developing regardless of oil type.



+1

I've also run synthetics, mostly Mobil1, in older engines and never noticed a difference in regards to leaks one way or another...

I think you'd be fine and that weight might be ideal.

 

[GT Mike]

I've been using Schaeffer's 7000 10W30 in my Jeep since I bought it used about a year or so ago. Even with relatively low miles (~60k) I still get the occaisional lifter clack on a cold start. It goes away within a few seconds. I haven't thought too much of it, because as was mentioned, the 4.0 is durable as granite, but far from being a refined, polished engine.

I've thought about using a different brand, but somehow always go backk to Schaeffer's. It's never let me down in anything I've used it in. I can get it for a good price, and I like it's funky green color.

 

[Kcoastie]

Well after I remembered that WalMart will take back almost anything in the world I took my whole 15 bottle stash of M1 EP to them and returned it for a $113 gift card. Not bad huh? I think I'm just going to let the dealer change the Journey's oil and I'm going to finish the ARX treatments I'm running and then after that's done probably switch to Pennzoil HM, Castrol HM, or possibly the Valvoline Maxlife. Anybody have a suggestion between these 3 oils? I noticed the Maxlife was syn blend. Kinda leaning towards the Pennz because of their good reputation on here. I don't have any problems at all with burn off using a 10w-30 either, fyi.

 

[demarpaint]

I'm just about finished returning my Mobil 1 stash too. Of the 3 oils you're thinking about I'd go with the Pennzoil. Pennzoil products get great reviews here, and will serve you well. JMO

 

[Pop_Rivit]

We sold our 1998 Cherokee (4.0) with 247,516 miles on it 2 years ago. It had nothing but synthetic 10W-30 with about 8-9K oil/filter changes. You'll be fine. I don't think I'd do the ARX cleaning, just put the oil in and drive happy.