Cylinder head replaced and now jeep is running hot

[Schwarz81]

Had a blown head gasket and since my head was not the TUPY version, I went ahead and replaced with one from Clearwater. Runs great BTW. New thermostat and housing along with exhaust while i was at it. Entire cooling system was replaced a year ago. Coming to work today the temp was steady at 210 but then started to creep over and stayed a little past 210. I thought the fan clutch but it had some resistance when I tried moving while the engine was still warm. Any idea why my engine is getting so hot? Prior to the head replacement the jeep always ran at 210 and never over so this is a new problem.

 

[Juggernaut]

There's a chance air is trapped in the cooling system after you did the work. Burp the system to be certain so you can rule that out.

 

[RobertJ]

There's a chance air is trapped in the cooling system after you did the work. Burp the system to be certain so you can rule that out.

This would be my guess too. 4.0s are notorious for this. To burp, park uphill or park it on ramps and open the radiator cap. You'll probably be able to put some fluid in.

 

[Goatman]

What gauge are you using? The factory gauge is not an accurate indicator, more of a rough suggestion. 210 isn't overheating either. Next time it gets warm try running the heater full hot. See if that brings your temp down.
My 06 runs around 210 all day every day.

 

[qslim]

I second air in the system. I had to park mine in my neighbor's inclined driveway and use a fill funnel to finally get all the air out. These funnels are real handy tools for filling coolant, they cut down on the mess & make burping the system very easy. You can usually find them at HF or Walmart.

 

[Daveh370]

I second air in the system. I had to park mine in my neighbor's inclined driveway and use a fill funnel to finally get all the air out. These funnels are real handy tools for filling coolant, they cut down on the mess & make burping the system very easy. You can usually find them at HF or Walmart.

View attachment 167642

I used this same kit when I replaced my radiator last month. No issues with air in system, runs perfectly. Highly recommended.

 

[Schwarz81]

just burped the radiator but it wasnt on any incline and didnt seem to help. Drove around and temp went over 210 immediately. the temp did however stay steady at 210 while it was burping so the temp increase only happened while driving. You could clearly see bubbles when the cap was off so maybe burp again when the engine cools?

 

[Daveh370]

just burped the radiator but it wasnt on any incline and didnt seem to help. Drove around and temp went over 210 immediately. the temp did however stay steady at 210 while it was burping so the temp increase only happened while driving. You could clearly see bubbles when the cap was off so maybe burp again when the engine cools?

Burp again, while the Jeep is parked on an incline. Gotta that radiator opening as high as you can.

 

[Chris]

In all fairness, every 4.0 I've ever owned (which is about 10) has always hung out around 210 to 220 (slightly over the 210 mark). This is 100% normal (especially on hot days), as long as the temp isn't going much over that.

 

[Schwarz81]

I replaced the radiator and temp is holding now. Guess the old rad was plugged from the coolant/oil sludge from the blown head gasket. Thx for the replies