3.6 Penstar Poll!

[Charles 236]

Don't sweat 225 or 230° engine peak temps. I have a copy in my toolbox of a factory publication about addressing excessive engine temp complaints. According to the engineering department, it isn't overheating below 245° engine temp. That does require that the cooling system is operating properly and has the correct percentages of correct coolant and distilled water. Also, Jeep fans are loud, which has caused a few complaints of overheating when there actually was no problem.

Sponsored

 

[Stan H]

Don't sweat 225 or 230° engine peak temps. I have a copy in my toolbox of a factory publication about addressing excessive engine temp complaints. According to the engineering department, it isn't overheating below 245° engine temp. That does require that the cooling system is operating properly and has the correct percentages of correct coolant and distilled water. Also, Jeep fans are loud, which has caused a few complaints of overheating when there actually was no problem.

My coolant is 50/50 coolant Specification correct. Zerex or some big name brand aint got it with me . Since I replaced water pump and coolant reservoir bottle aint needed to have it with me . I carried it for 2 months afterwards kept forgetting to take it out of the bed . I come home wore out then get up in the dark and take off . Getting old I guess

 

[ShadowsPapa]

Don't sweat 225 or 230° engine peak temps. I have a copy in my toolbox of a factory publication about addressing excessive engine temp complaints. According to the engineering department, it isn't overheating below 245° engine temp. That does require that the cooling system is operating properly and has the correct percentages of correct coolant and distilled water. Also, Jeep fans are loud, which has caused a few complaints of overheating when there actually was no problem.

I bet if I dug up some of the documents on what an unmarked temp scale means, testing thermostats and so on - people would not believe what I posted.

Jeep fans ARE loud. When I needed to drive my truck with the snow plow on I had to trick it into running a fan test while on the highway to get the HVAC to work. The engine was not running hot (only about 225 or so), but the temp sensor said it was 90 degrees outside so the heat refused to work. I had to force the fan into high to overcome the vacuum created by the snow plow and get some of the 10 degree air to flow across the temp sensor to get the cabin heat to function!

Proper coolant mix and a good pressure cap means your coolant won't boil until over 265 degrees or somewhere in there (can't recall the exact number but it's over 260 - might be higher with these high pressure caps. I'm used to 13-14 psi, 16 on some with AC "back in the old days")

 

[Mr Miami]

Either turn the AC on, or simply wait for the engineered controller to kick the fan into high. People tend to freak out over the numbers because you can see them now, before it was just a gauge usually with no numbers. Oh, wow, water boils at 212 and I'm running 225! To that, I generally say "so?"
Thousands of Jeep engines of all shapes and sizes have operated in the temperatures people are now worried about - and they've all survived fine.
Did you know that the specs for a 195 thermostat for a 1980s engine say it doesn't fully open until about 225 degrees? So you don't even have full water flow until 225 degrees (I believe some go up to 227 before fully open).

I have to think more like you when it comes to the temperatures. I have the 3.6 in my '16 Willys JKU and have been getting the engine light about cooling (can't remember the number now). I do run it a lot for short trips to the food store, mall and other places that are no more than a mile or two from my house. Since I was getting the light periodically, I started checking my coolant temperature and it was never getting up to about 190-195 F unless I drove it for maybe 5 miles or more. However, my new JTR gets that hot in 1/2 mile or about 2 minutes. In normal driving, it runs at about 195 F.

On the JKU, I just reset the check engine light and it is good for another 3 months or so.
So I decided to "fix" the problem and get a new thermostat. About 2 months ago, I called several dealers (I wanted the Mopar one) and finally found one for about $80. The other dealer that had them wanted more than double that price. Anyway, both said they are 203 F thermostats. That seemed high to me since both of my 3.6's rarely hit 200 F but from what I am reading here it is ok to be in the low 200's.

 

[Charles 236]

It's a 21 PSI cap, and I have tested many that only hold pressure up to 15 or 16 PSI. My SnapOn pressure tester only reads to 20 PSI, but I figure that if it can't hold anymore than 15 PSI, the cap is bad anyway. Even at 15 PSI, the 50-50 coolant mix isn't going to boil below something like 256° if I remember correctly.

Definitely use the Mopar thermostat, I have replaced a number of new aftermarket thermostats. The customer usually wanted to save some money, but doubled their cost. It would have been cheaper to buy the Mopar one to start with.

 

[Zilla]

Kinda intrested to see how this community feels about the primary power plant of the sickest truck ever made.

I'm really sorry that your Jeep is sick, and I hope it gets well soon.

 

[PuddleJumper]

I'm really sorry that your Jeep is sick, and I hope it gets well soon.

Funnily enough she lost a wheel last night and is at the dealership undergoing some surgery. I appreciate your concern and wishes.

 

[Zilla]

Funnily enough she lost a wheel last night and is at the dealership undergoing some surgery. I appreciate your concern and wishes.

Gee......I hope it wasn't something I said!

 

[DanW]

What kinds of temps is causing all the concern? These engines are fine at the temps they run. The oils today are outstanding. Even Walmart Supertech is a good oil. Most of these engines are running bulk dealer or quickie change oil and they do just fine. Btw, ALL 0w20 oils I´ve seen are full synthetics, which in most cases means Group III at a minimum, and Group III is excellent base oil. They can handle much higher heat than any healthy Pentastar is going to throw at it. There is a huge safety margin.

 

[jmr]

I'm curious - are the cam part numbers the same?

Same heads and cams for the UPG I 3.6 RAM 1500 and JL/JT.
The RAM 1500 has 20HP more with the same torque.

 

[Stan H]

Same heads and cams for the UPG I 3.6 RAM 1500 and JL/JT.
The RAM 1500 has 20HP more with the same torque.

Torque is low end and Horsepower in the top end . Not that advantageous unless your running 4500 RPMS all the time.

 

[jmr]

Torque is low end and Horsepower in the top end . Not that advantageous unless your running 4500 RPMS all the time.

The gain for the RAM has to be in the tuning for that extra 20 HP. A DOHC 4 valve engine tends to be high revving with the 3.6 the power is upstairs absent of low end torque. In contrast to 2.0L turbo on the dyno has allot more low to mid range torque than the 3.6l.

 

[cb4017]

I voted it is an okay engine.
I had a 21 JT Max Tow. I stuck a Mopar Performance suspension on it and ran 33" Rubicon take-off wheels & tires.

I always felt the engine was adequate but wished it had a little more power, especially when towing my little r-Pod TT. Add me to the list who thinks a 5.7L engine would be perfect.

I'm currently driving a 23 Colorado ZR2. Awesome truck, but for some reason I continue to miss my Gladiator.

If I could get a 5.7L Gladiator I would trade the ZR2 in tomorrow.

 

[Stan H]

I voted it is an okay engine.
I had a 21 JT Max Tow. I stuck a Mopar Performance suspension on it and ran 33" Rubicon take-off wheels & tires.

I always felt the engine was adequate but wished it had a little more power, especially when towing my little r-Pod TT. Add me to the list who thinks a 5.7L engine would be perfect.

I'm currently driving a 23 Colorado ZR2. Awesome truck, but for some reason I continue to miss my Gladiator.

If I could get a 5.7L Gladiator I would trade the ZR2 in tomorrow.

Come back to the Gladiator. Surprised that Chevy aint went bust already

 

[cb4017]

Come back to the Gladiator. Surprised that Chevy aint went bust already

Thinking about it. There seem to be some decent discounts out there. A Mojave is calling my name.

Sponsored