Hey all,

Just drove my new XJ home, about an hour drive. I kept a close eye on the engine temp, after reading all of the threads about overheating.

It stayed perfectly in the middle, right where I expected it (all highway driving), but when I opened the hood to snap some shots, I nearly burnt my hand!!!

It was way hotter than any engine bay I've seen. Its pretty hot here today, but I dont think the pop rod should burn me...

Could my gauge be reading way off?

 

It's the same for me, but we're in the middle of summer, so you have the sunlight shining on your hood, which means added heat especially if you have darker paint, which absorbs light instead of reflecting it.

As long as your gauge appears to work, it's likely not faulty. The coolant sensor isn't a very fail-prone part of the 4.0L, so I wouldn't worry to much about it being off unless a check gauges light comes on.

 

Jeep hood in sun without being driven on 80* day: ~140*

Trailblazer (DD) hood after being driven: ~90*

Massive difference but don't worry unless coolant system isn't up to par and its running hotter than it should..

 

What accounts for that huge difference, your Trailblazer is white?

I see your XJ is black.

 

Ha-ha, my example was def less than scientific, but the TB is silver so there is a significant difference. The hood of my dad's dark blue F150 was ~130 on a similar day after driving. The thing I noticed is that even when running and sitting in sun, the xj's hood wasn't too much warmer than off and sitting in sun. Maybe a 10-12% increase, which starts to borderline on a significant difference but that isn't representative of underhood/coolant temps.

 

At 90 degrees outside and with it running I can't touch mine because it burns my hand.

 

Yup, felt like I took the arm hair off last time I leaned on my hood after wheelin... That's a one time mistake. The difference between 140°F and 160°F can feel like the fire of a thousands suns rather than only 20° warmer... That said, I'd be curious to see a temp reading of an xj hood under extreme exterior heat and engine temps.

OR...

If you can't take the heat, stay out the xj. But this part is just a joke

 

Yea my hood used to get that hot too and that's a white XJ with the under hood insulation still intact, but I installed a vent and hood surface temp dropped noticeable, from burning my hands to, I can now hold them on the hood comfortably.

 

This doesn't necessarily answer your question but I thought you might find it interesting. This is a seek thermal imaging camera capturing a walk around of an xj.

 

OK I want one.

 

A seek camera? They're pretty cool, this isnt my video but I think Ill be getting one soon. could really help out in diagnostics!

 

Haha that's cool.

 

Heres a vid I did with my Seek cam looking inside the engine bay with motor running.

 

LOL dumajones I just now realized I found your channel I few months ago and never connected you to the forum until now! When I posted that video earlier I was actually trying to find one of your videos but I found this one instead and I though it showed the hood temp a little better. You've had some stupid close calls up there, glad you did the disc conversion!

 

Flir or the Seek, likely I would buy the Flir.

Heres another use,


Dont do this, but consider it a public safety message.