Temp Difference with Previous Pentastar

[flyer92]

I own a 2021 2-door JL and a 2016 Grand Cherokee, both with Pentastar engines. However, I quickly noticed that the engine oil temp in the JL is usually about 20 to 30 degrees hotter than the Grand Cherokee under the same driving and environmental conditions. I'm not 100% certain about why this occurs, but I suspect it is because the Pentastar in the Grand Cherokee is the previous version of the engine that requires 6 quarts of oil instead of 5. My theory is that the greater oil capacity dissipates heat better, but just curious what others think and if anyone has noticed differences in engine life/performance as a result. Appreciate the feedback and happy Jeepin' y'all!

Sponsored

 

[Deleted member 59498]

Might be air flow also and perhaps larger radiator?

 

[Old Dogger]

In 2016, the Grand Cherokee was the first Jeep to have the 3.6 PUG engine. The Jeep Wrangler didn’t receive it until 2018 in the JL. So it Is the same engine..FYI Unless your 2021 has the 2.0 engine?

 

[Cthehentz]

It could be emissions related, have you compared the engine coolant temp between the two?

 

[JL ME]

They probably have different thermostats. That would give you different operating temperatures.

 

[flyer92]

In 2016, the Grand Cherokee was the first Jeep to have the 3.6 PUG engine. The Jeep Wrangler didn’t receive it until 2018 in the JL. So it Is the same engine..FYI Unless your 2021 has the 2.0 engine?

Yes, it is the same 6-cyl engine, but the oil capacity is different. The early version on the Grand Cherokee is 6 quarts and the newer version in the JL is 5 quarts. I believe that more oil dissipates more heat, which is why the earlier engine runs noticeably cooler. This seems to make sense to me, but just wanted to see what others think about that theory.

 

[flyer92]

It could be emissions related, have you compared the engine coolant temp between the two?

Unfortunately, there's no way to compare coolant temp because it isn't displayed in the Grand Cherokee's engine parameter pages on the dash. You can only compare oil temps between both vehicles.

 

[five9dak]

Unfortunately, there's no way to compare coolant temp because it isn't displayed in the Grand Cherokee's engine parameter pages on the dash. You can only compare oil temps between both vehicles.

Hand held scanner can show that PID as live data if you really want to dig into it.

 

[mwilk012]

1 extra quart of oil in a sump isnt going to cause an effective change in oil temps. More likely that there is something wrong with your GC.

 

[flyer92]

1 extra quart of oil in a sump isnt going to cause an effective change in oil temps. More likely that there is something wrong with your GC.

I was actually thinking the opposite, until I drove other GCs and JLs with the same Pentastar versions. The oil temp difference has been the same as what I'm currently experiencing, so it is either due to the difference in oil capacity or perhaps a different thermostat, as others stated previously.

 

[58Willys]

A larger oil capacity would add to cooling effect, but I don’t think it be anywhere near 20-30 deg.

What are the two temps?

 

[flyer92]

A larger oil capacity would add to cooling effect, but I don’t think it be anywhere near 20-30 deg.

What are the two temps?

Depends on the driving conditions. But, as an example....while cruising down the freeway at 75 mph, the GC's oil temp is around 185 degrees, while the JL is around 205 degrees.

 

[1BadManVan]

Depends on the driving conditions. But, as an example....while cruising down the freeway at 75 mph, the GC's oil temp is around 185 degrees, while the JL is around 205 degrees.

Is this usually when you are observing the difference? A theory for that could be the Jl having to work harder to maintain those highway speeds due to being a brick lol. Also maybe less airflow getting through to the engine bay while driving.

Do they idle roughly the same temp??

 

[mwilk012]

The oil cooler will maintain oil temp pretty much right in line with coolant temp. Thermostats for both should be the same.

 

[flyer92]

Is this usually when you are observing the difference? A theory for that could be the Jl having to work harder to maintain those highway speeds due to being a brick lol. Also maybe less airflow getting through to the engine bay while driving.

Do they idle roughly the same temp??

No...the JL's oil temp is always higher than the GC's, regardless of the driving mode/conditions.

Sponsored