Hey folks! Hemi overheatin....only on initial startup.

2003 dodge hemi.

day 1.
no problems pullin rv

day 2.
key point STARTED THE TRUCK UP EARLY MORNING.
Pullin a 7,000lb trailer day 2 and engine overheats. ease off throttle and it goes back to normal. Now I floor the throttle. needle never moves.
Get gas and lunch and attempt to merge onto interstate. engine gettin warm fast. ease off throttle temp normal and then the gauge will NOT MOVE FROM CENTER no matter hard hard i run the engine after this first spike of overtemping. get filled up at gas station quickly and engine temp stays in the middle no matter what i do.

day 3 through 9 same issues.

Throughout the summer I have this same issue ONLY WHEN I'M PULLIN THE RV! And of course only during the first start of the day.

Now it's fall and the temps are around 60 degrees. Having the same problems without the trailer.

What would cause allow the engine to overtemp on initial startup. afterwards it will take abuse all day long and have no issues??? AS OF YESTERDAY the temp spiked upwards around town just the pickup and me. after it relaxes back to the middle of the gauge i floored it frequently and it will never increase temp.

TODAY
same as yesterday but the temp gauge fluctuates ever so slightly from top center after this initial spike of temp.

Crazy! Hemi likes to overtemp then it's happy as long as the engine doesn't sit for any period of time and cool down.

 

i would try changing the thermostat and maybe flushing the rad.

 

Sounds like a sticking or mis-operating thermostat. It appears like it opens eventually, but not until it gets real hot.

 

I think these two have answered your question my friend. If you're gonna change it, just go with a 180* thermostat. It will keep the truck even cooler since you tow.

 

+1 I had a similar experience. The 'stat would stick closed every now and then. The 180 won't necessarily make it run cooler, though. It'll reach the temperature it needs. The cooler 'stat just opens sooner.

 

My truck did the exact same thing. The Thermostat began to separate and became partially inoperable.

 

thanks! i will do that. will let you know what happens after i get it fixed. appreciate it.

 

Many Thanks! problem solved. Next time I should have purchased a gallon of antifreeze before I started to the project. Easy fix, hardest part was that the power steering reservoir was in the way of my socket set.