Oil weight suggestion for next OC for 4.0

[JeepWJ19]

Hello again everyone , I've been talking to some people but would like a wide discussion on what weight you guys would run next.

Like mentioned I have a 4.0 straight 6. I have tried many oil weight combos to try to solve this minor lifter ticking. Right now it has been optimal and almost completely non existent with my current setup of 5qt 10w30 PHM and 1qt of 5w30 PHM and a Motorcraft FL1A filter. Here in the summer the ticking does not last for more than 10 seconds at most. But when the cold comes it will get worse (obviously).

I have tried PYB 6qt 10w30, PYB 5qt 10w30 and 1 qt 5w30, PHM 6qt 10w40, PHM 6 qt 10w30 and PHM 5qt 10w30 and 1qt of 5w30. Upon them, it seems like my 4.0 likes the thicker PHM BUT likes the flow of the 5w better at cold start to battle the cold start tick.

And here is where I'd like your opinion or criticism on my thoughts. My next oil change should be in august and then the following oil change should be right around december or january (super cold months in PA). I was thinking of two options for the August oil change that will initially be warmer temps but as I head into fall the temps will be falling.

1.) PHM 4qts of 10w30 and 2qts of 5w30 since it will be transitioning to colder temps in the fall
2.) PHM 5qts of 5w30 and 1qt of 10w40.

I plan on doing number 2 definitely for the winter. After discussing with KayCeeJeep he has noted that the 5w30 tends to shear around 3000mi. Is #2 risking it with hot august but cooler fall? I'm a little more worried if I run it in the hot august months and oil pressure really drops...

As a side note: my oil pressure 'seems' fine per the gauge on the dash. 55-58psi at cold start, normal driving hot 40-45psi and hot at idle fluctuates between 28-32psi. No power loss at all - funny thing and even my father mentioned it, my 2002 4.0 actually has a quick throttle response and has more power than his 2004 4.0 WJ

I appreciate all responses

 

[umungus1122]

6 qts. PZ HM 5w-30. No, there's no danger using it. No need to mix qts. of this grade and that.

 

[bullwinkle]

On my 4.0 XJ both the XG8A Ultra & the MC FL400S have done a decent job with preventing overnight drainback/ticking, & MaxLife 10W40 has helped with hot idle low oil pressure (5W30 was under 15 PSI if the gauge was to be believed). One factor could be the junk exhaust manifolds on these, they seem to leak cold & get quieter when they heat up. Fortunately the engine on mine looks like it will outlive the unibody, I probably have 4 or 5 more winters left before it'll get too weak to drive.

 

[JeepWJ19]

Originally Posted By: umungus1122
6 qts. PZ HM 5w-30. No, there's no danger using it. No need to mix qts. of this grade and that.


Really? That's a tad surprising

 

[aquariuscsm]

Run either 10W30 Pennzoil hm or Pennzoil 10W40 hm. Mixing all those different grades is silly and just unnecessary.

 

[gfh77665]

Either strategy is perfectly fine and safe. You are correct about the eventual shearing, too.

Personally, since I got a wide variety of weights (bought at large discounts) on hand, I do run 10-30's and 10-40's and even the occasional SAE 30 wt. in the heat of the summer, and the 5-30's during our mild winter, just to optimize.

 

[JeepWJ19]

Originally Posted By: bullwinkle
On my 4.0 XJ both the XG8A Ultra & the MC FL400S have done a decent job with preventing overnight drainback/ticking, & MaxLife 10W40 has helped with hot idle low oil pressure (5W30 was under 15 PSI if the gauge was to be believed). One factor could be the junk exhaust manifolds on these, they seem to leak cold & get quieter when they heat up. Fortunately the engine on mine looks like it will outlive the unibody, I probably have 4 or 5 more winters left before it'll get too weak to drive.


Yes, very tough situation. It likes a thick 5w for cold starts but always loves a 40weight at running temp. I never paid any attention to the exhaust manifolds. My exhaust certainly seems louder than other stock 4.0 WJs I've seen but I never really attributed it to anything other than maybe I'm special

lol.

 

[JeepWJ19]

Originally Posted By: aquariuscsm
Run either 10W30 Pennzoil hm or Pennzoil 10W40 hm. Mixing all those different grades is silly and just unnecessary.


It doesn't seem to be unnecessary. As I've previously stated the best of yet has been the 1qt replacement of 5w30 to the 10w30. So it seems that at cold start it likes the better flow.

 

[SwampSurvivor]

My 4.0 has no problem with 10w-30 in Central NY winters. After years of trying various 5w-30s, mixing 10w-30 with 5w-30 and 5w-40 ... I think they are happiest on 10w-30 all year.

I don't have the maintenance book on me at the moment, but i have run Pennzoil conventional 10w-30, Valvoline MaxLife 10w-30, Pennzoil High Mileage 10w-30 and current/next OCI will be Supertech Synthetic 10w-30.

I am not easy on my Jeep, either. It gets used as a Jeep. I tow/haul, and go off road. Which means either idling all day in 4LO or bouncing off the rev limiter in mud.

10w-30 is going to serve it well towing my popup to Rausch Creek and back next weekend

 

[JeepWJ19]

Originally Posted By: Miller88
My 4.0 has no problem with 10w-30 in Central NY winters. After years of trying various 5w-30s, mixing 10w-30 with 5w-30 and 5w-40 ... I think they are happiest on 10w-30 all year.

I don't have the maintenance book on me at the moment, but i have run Pennzoil conventional 10w-30, Valvoline MaxLife 10w-30, Pennzoil High Mileage 10w-30 and current/next OCI will be Supertech Synthetic 10w-30.

I am not easy on my Jeep, either. It gets used as a Jeep. I tow/haul, and go off road. Which means either idling all day in 4LO or bouncing off the rev limiter in mud.

10w-30 is going to serve it well towing my popup to Rausch Creek and back next weekend


I would think so too but it doesn't seem likely for my case. My dad's 4.0 loves the PHM10w30 but mine seems to be a tad more picky haha.

But thanks everyone I think I will try #2 next oil change!

 

[Ramblejam]

Originally Posted By: bullwinkle
(5W30 was under 15 PSI if the gauge was to be believed).


The dash gauge isn't exactly the most accurate in the world, and the senders wear out.

However, all you need is 13 PSI at idle per the FSM.

 

[DemoFly]

Originally Posted By: JeepWJ19
Originally Posted By: aquariuscsm
Run either 10W30 Pennzoil hm or Pennzoil 10W40 hm. Mixing all those different grades is silly and just unnecessary.


It doesn't seem to be unnecessary. As I've previously stated the best of yet has been the 1qt replacement of 5w30 to the 10w30. So it seems that at cold start it likes the better flow.

I'm sorry buddy, but total placebo.

Just run 5w30. 10w30 and 5w30 are both 30 when hot.

 

[JeepWJ19]

Originally Posted By: DemoFly
Originally Posted By: JeepWJ19
Originally Posted By: aquariuscsm
Run either 10W30 Pennzoil hm or Pennzoil 10W40 hm. Mixing all those different grades is silly and just unnecessary.


It doesn't seem to be unnecessary. As I've previously stated the best of yet has been the 1qt replacement of 5w30 to the 10w30. So it seems that at cold start it likes the better flow.

I'm sorry buddy, but total placebo.

Just run 5w30. 10w30 and 5w30 are both 30 when hot.


I'm sorry if I didn't make it clear, the main concern of this was cold start weight not the weight at operating temp....

 

[SwampSurvivor]

Have you tried different filters to prevent dry starts?

 

[umungus1122]

Originally Posted By: JeepWJ19
Originally Posted By: aquariuscsm
Run either 10W30 Pennzoil hm or Pennzoil 10W40 hm. Mixing all those different grades is silly and just unnecessary.


It doesn't seem to be unnecessary. As I've previously stated the best of yet has been the 1qt replacement of 5w30 to the 10w30. So it seems that at cold start it likes the better flow.

This would in no way be perceptible, to a person or the engine.

 

[JeepWJ19]

Originally Posted By: Miller88
Have you tried different filters to prevent dry starts?


Yepp. Stock OEM MOPAR MO-090, Fram TG16, and Fram TG8A. Seemed to be no difference between the three of them

 

[umungus1122]

Originally Posted By: JeepWJ19
Originally Posted By: umungus1122
6 qts. PZ HM 5w-30. No, there's no danger using it. No need to mix qts. of this grade and that.


Really? That's a tad surprising

I'm not sure why it's surprising, we've had several 4.0 that got nothing but 5 or 10w-30 conventional and have gone 200-350k, with no abnormal engine wear.

 

[JeepWJ19]

Originally Posted By: umungus1122
Originally Posted By: JeepWJ19
Originally Posted By: aquariuscsm
Run either 10W30 Pennzoil hm or Pennzoil 10W40 hm. Mixing all those different grades is silly and just unnecessary.


It doesn't seem to be unnecessary. As I've previously stated the best of yet has been the 1qt replacement of 5w30 to the 10w30. So it seems that at cold start it likes the better flow.

This would in no way be perceptible, to a person or the engine.


Why wouldn't it? I don't mean to question the validity of your post but I am quite skeptical since I'm the one who has been driving this for 4 years and always pays attention to every noise.

As I remember when I had straight 10w30 PHM it would stop ticking when temps got around 115*F per the temp gauge on the dash, every day, all the time when I would start the jeep in the morning after shutting it off.

Now? I don't even make it out of my development before it stops and the ticking is not as loud.

 

[Nitronoise]

might want to try rotella T-6 5W40 , I am trialing it in my jeep and so far so good

 

[JeepWJ19]

Originally Posted By: Nitronoise
might want to try rotella T-6 5W40 , I am trialing it in my jeep and so far so good


That is one of the oils that has come across my mind. It seems like the perfect combo is a 5w40 for my 4.0. It seems pretty stout as well, but it being synthetic, it is on the thin side vs the Pennzoil HM. Maybe I'll give the thinner PYB 5w30 a shot before I dive straight into Rotella lol!