6.4 Engine Temps

[Sunburn]

For those who have a 6.4 Hemi in your JK/JKU, what are your peak engine temps you see?

[scubatech]

For those who have a 6.4 Hemi in your JK/JKU, what are your peak engine temps you see?

When I had my 6.4 Liter my fan would turn on @ 212* , off @ 204* F. Normal highway cruise 208* - 210*. Once in a great while the fan would wait until 225* to turn on which I think the TIPM was allowing it to default to the factory 3.6 Liter fan temp setting. Long high altitude climb 212* - 215*. Fan would kick in at the 212* & cool it quickly down to 204* & turn off. Note, that on long climbs the engine will require the fan to turn on to control temperature. My vehicle never overheated even when ambient temp was 100*. I did have a C & R radiator in my Jeep. These V8 Wranglers need a lot of fan usage to keep the temps in check. I wish it would have had a half speed feature that would have allowed it to run all the time on the trail and switch to high speed when needed because it won't run long without the fan as you know.

[Sunburn]

scubatech, thank you for the reply. I've got the 180* thermostat and the fans will normally kick on at 203* - 208* and I've seen a peek engine temp of 221*. At what temps would you get concerned?

[scubatech]

scubatech, thank you for the reply. I've got the 180* thermostat and the fans will normally kick on at 203* - 208* and I've seen a peek engine temp of 221*. At what temps would you get concerned?

I know these engines will run OK @ 230* but I don't like it. If the fan wasn't pulling the temp down at the 230* point I would start getting nervous. That Pentastar fan will do that with no problem unless there is another issue. I was at SEMA so I just saw your post.

[Sunburn]

I appreciate! I feel better having a bench mark so not I'm not constantly worrying about engine temps. I hope you had a good time at SEMA, I'd love to make it out there one day!