[rubberduck]

Hello,
I have a 2001 Dodge Ram 1500 V6 (3.9L). About 5 months ago I was driving my truck down the highway. I heard what sound like a pop and then a sound that sounded like some gravel hitting my undercarriage. I pulled over and checked my tires and looked all around my truck and engine and nothing looked out of the ordinary. I shrugged it off and continued down the road. After driving for a little while I realized my truck was running a little hotter than normal. A few days later I flushed the radiator and it was pretty gross and after my truck for most part started to run normally. About a month went by and I was washing my truck. After I finished I was driving back home and noticed that it was running hot again except this time the gauge was kind of moving. I realized that the faster I was going the hotter it would get. Yes I know it should be the other way around but its not. If I keep it below 55, it runs somewhat normal. But as soon as I get over 55 I can watch the gauge go up. When this happens I can slow back down to about 40 45 or so and in a few minutes my truck will be somewhat normal again. I have replaced the thermostat, fan clutch, my radiator is fine, no leaks, the cap is tight, water pump circulates just fine. I really have no idea what it could be other than my actual gauge may be messed up. Please if anybody has ever heard of this let me know what it is or what it could be. Thanks

[TxGreaseMonkey]

I suspect the radiator needs rodding or replacing, due to phosphate scale build-up. The situation will likely get worse, over time. After the repairs are made, refill with a 50/50 mixture of G-05 antifreeze and distilled water.

These links should help:

https://www.askmehelpdesk.com/cars-t...tml#post235973

http://www.valvoline.com/pdf/Zerex_CoolantChart.pdf

Pilots crash all the time by not trusting their gauges.