noticed my D was running hot. Only 48k on the 4.7L V-8. Not towing or running AC either. So I changed and flushed my fluid, then changed Tstat, then the Temp. sensor unit. No oil in the fluid or coolant in the oil. Heater is good with no steam coming out. The exhaust is normal. Could I have a premature water pump failure or what? No leaks in the system and I bled all the air out possible. oh yeah new rad. cap too. What the he^$.

 

Your system may be clogged somewhere. take off your rad cap turn on your rad cap, turn on your "D", then let your engine heat up if the water is not flowing were the cap goes than your system is clogged. maybe the heater core or the radiator. does anyone else have any thoughts that are possitive for USAFJOE?

 

thnks dro318, I tried it and dont really see the fluid moving in the radiator. Only rises up to the top of rad neck as engine warms. Should I be seeing substantial fluid movement? could my w. pump be shot? I just cant believe the radiator or core is plugged with only 48k and the fluid that I flushed out was so clean.

 

What size engine do you have. with the cap off let the "D" warm up let it get to 210 or better then check for the flow. by then the T- stat should of opened up. If there is no clogg you should see some flow. Keep us updated please maybe someone else may hay something to add...

 

I have experienced same problems, i then checked every single piece in the coolant system and it took much time if you are diagnosing it yourself, so better go for simple things, you never know. check hoses , there might be leaks on it, you have to be 100 % sure about the leakage be4 going to something else, and the best time to check the leak is when you turn of you D after a long trip (then check it after 10 mins), the Water Pump is important too, but i don't think it's the WP, you can check that by doing the above recommendation, you should see flow and you can't see flow unless the water level is not full in the hose, so u can decrease the level by absorbing some.

check the fan Clutch, if the car does have a noticed Air pressure when you started your D after long time sleeping then it decreases itself gradually, the the Fan clutch is Ok, what else, the aux. Fan, check if it working not faking, i had the same issue in my D.

we don't want to go further to headgasket & Cyilnder hairline because im very sure it's a leaking somewhere.

pls answer these question, when does the car overheat and what dash it reaches..
what T-Stat you are using ? 195 F or what
have you ever changed hoses..

Thanks.