I have an 05 ram 1500 with the 4.7l engine. A few weeks ago out of nowhere I noticed that the temp gauge was going about a quarter above middle. Took it to a shop and somehow the radiator was almost empty. I had a water pump and thermostat replaced about 6 months ago. The shop filled up coolant and checked for visible leaks in the system both while off and when running. They did this for about an hr. nothing. Now I may just be paranoid , but It also seems like the engine temp is getting up to temp within 5 min of driving from a cold start. Then it will stay right below the middle most of the time. But will go above slightly from time to time. Up until this started it was always in the middle. Maybe this is due to weather getting warmer here in Atlanta, but I swear its always been at the middle. Oh and it seems to go a higher during highway driving and random times when at idle. Just looking for any insight at what the problem may be? Or am I just paranoid because I am now watching the gauge constantly. Any help is appreciated. Thanks, ken

 

In the middle is about right with the stock 203 'stat. A 180 will make it settle around 5/16 or so. "... quarter above middle." Is that 3/4 or 5/8? Higher on the highway is not good. You may have a stuck 'stat or a blockage somewhere. The problem is the location of the 'stat. For some reason, they put it in the lower hose instead of a higher location. I'd say try removing the 'stat and see what you get. It'll be a messy PITA due to the location.

 

Check your clutch fan for slipping. There are tests you can do when your engine is not running..basically checking for it's resistance to rotate by hand when cold and hot.
Also, your rasiator could be getting clogged. Feel the coolant hoses. One should be a tad cooler than the other(lower). If they are the same temp, your rad is probably not working that well.
Could be mixture of both.

 

Thanks all.. Appreciate the info...

 

how can you tell if you have the stock 203 stat? I just bought a 2002 Dodge ram 4x4 SLT QC a few days ago and I noticed it was about halfway. I just kept an eye on it to make sure it didn't go any higher.

 

Keep a very close eye on that. My '02 Ram 1500 4.7L started fluctuating in temp about three months ago, used to always sit right in the middle half mark. Then it got hot a few times, I tried to never let it outright overheat or shut itself off. After about a week I had the time to change the thermostat; ran back to normal for about week then ran hot again one day. Now I have a bigger problem - See "'02 Ram won't start" post thread - think I've got blown head gasket now - engine is locked up and won't start.