99 K3500 454 overheats under throttle

[99BB3500]

Hello all! I bought a 99 K3500 7.4 CCLB a couple weeks ago. I haven’t really been driving it much. I maybe put 50 miles on it just to see what all the bugs were so I know what to expect. I’ve been pretty big into the jeep world until people ruined it for me so I sold my Cherokee and bought this. So far it stumbles once you hit the gas but clears up a few second later. Feels like it’s under powered. Climbing any kind of hill and it starts to build heat. So far it’s never gone over 220-230. At idle the temp returns to normal. Is there anything I could check. I don’t really mind putting the time and the money into this truck because it’s one I’ve always wanted ever since I saw one. I’ve basically waited over 20 years and found one that the price was right and it wasn’t neat to hell and back. Thank you for any advice or help getting me in the right direction. I’ve been reading an awful lot on this truck so I kinda know what to expect.

 

[Raspi454]

Good lookin' pair of trucks!

 

[454cid]

I would suspect the radiator is plugged up.

 

[Supercharged111]

The needle on my dually NEVER goes past 210. You're missing something easy.

 

[454cid]

The needle on my dually NEVER goes past 210. You're missing something easy.

Thermostat not fully opening?

 

[99BB3500]

The needle on my dually NEVER goes past 210. You're missing something easy.

That’s what usually happens. At least with my luck anyways.

 

[stutaeng]

Does the 7.4 have those 2 senders like the 5.7? One goes to the ECU and the other to the cluster guage, and the 2 are not interconnected.

Hook up a scanner with live data to see what the ECU is saying.

Dunk your thermostat in an old pot of boiling water to see if it opens...or just replace it.

 

[0xDEADBEEF]

Check the fan clutch.

 

[99BB3500]

Does the 7.4 have those 2 senders like the 5.7? One goes to the ECU and the other to the cluster guage, and the 2 are not interconnected.

Hook up a scanner with live data to see what the ECU is saying.

Dunk your thermostat in an old pot of boiling water to see if it opens...or just replace it.

It does. I picked up both sensors. I also have a new thermostat I was going to put in just for peace of mind

 

[99BB3500]

Does the 7.4 have those 2 senders like the 5.7? One goes to the ECU and the other to the cluster guage, and the 2 are not interconnected.

Hook up a scanner with live data to see what the ECU is saying.

Dunk your thermostat in an old pot of boiling water to see if it opens...or just replace it.

It does. I picked up both sensors. I also have a new thermostat I was going to put in just for peace of mind