1997 Max, with this hotter weather has started to , for the first time see the temp needle head above the 'halfway mark' that it has always been at when at operating temp. It's never hit the 'warning' mark yet, but I've see it get a little too close for comfort.

101k, antifreeze changed out via 3-swap at 30k, 60k and again at 100k. New thermostat last week. Levels are fine. Fan relays seem ok, low speed at op temp, both on high with A/C on. I don't feel that it is just the gauge as it seems pretty warm under there, and also some of that 'rattling marbles' noise on moderate acceleration when the gauge is up some.

Now, when I changed the thermostat, on the side going towards the rad (towards the hose versus the block), there was a light covering of a sandy material. It would come off when rubbed. Looking in the oil, it's fine, looking in the rad overflow tank the antifreeze is clear no oil there either, tank is clean.

Looking down into the rad, no deposits seen, felt around a bit with my pinky, seemed clean from what I could feel.


Should I go for the coolant temp sensor, or is that a waste since the fans are operating as they appear they should?

Is the water pump going? I can hear a moderat rattling noise on that side of the engine.. Just don't want to think that it's gotta be replaced. ($550!!)

Thanks for reading and any thoughts?

 

do the stupid things first obviously youve covered a few like checking fluids. also double check there are no air bubbles in the cooling system...(open rad cap and squeeze the large upper hose gently to force fluid thru and air out.) its a common thing...if the fluids are good and no airs in the system pull your ecu codes and see if you have any "ghost codes" if it actually hasnt overheated yet i wouldnt worry too much and for a little piece of mind the car does run a bit hotter in this heat with the a/c pumping.....