My cars coolant temp rises steadily to at least 252 if idling. It did hit 268 at 70mph. It is a 02 coupe with 60,000 miles on it. There are no leaks. I have cleaned out the rad, changed and tested two thermostats. I have changed the water pump and removed the back cover of the first water pump and the front bearing and inner fan turn with the outside. I have made sure there is no air within the coolant system. The fans come on when they should which is 180 and they stay on. When i put my had over the fan a lot of air is come back. Not sure if this is normal but im thinking of pulling the rad just in case to really really clean it. I know that its fairly clean and would be surprised if this is the problem.

If I drive the car the temp only raises although when this first happened the coolant temp would lower as I drove and climb if I stopped but it was fairly cold out that night. I drove the car in the daytime (Orlando heat) and the temp would no longer fall only rise. I have checked the oil and there is no white smoke out the back.

I used a thermometer to test the coolant temp in the overflow tank and it goes up to 190 yet the DIC says 250. I would assume the coolant is hotter near the temp sensor then in the coolant tank but I don’t know this for sure. Still with the coolant tank low, once the temp reaches 250 the tank is very hot and would love to overflow if I opened it, therefore I think that temp sensor is good. Also the cars performace is perfect. The car runs perfect.

What do you think this could be? This is my daily driver and any help would be awesome, thanks. Matt.

 

As I mentioned in your previous thread, clean the sand from your cooling fins. You said there is no debris in there but you need to use compressed air to really blow it out.

 

are the fans working ? eg: are they on the whole time its above 240? i dont think ya can see inside the rad unless ya got a bore scope. have you serviced the cooling sys. if you pull the rad do yourself a favor and take it to a rad. shop that flow tests

 

Fixed. First thanks to all that relpied. After the new water pump install (thanks Max aka green machine) I did not get all the air out. Car is now at 190 temp, solid. Thanks again!!!

 

Second thread on the same subject as before.