Posted: May 24 2008 at 3:34pm | IP Logged

I have a 2000 Frontier crewcab with the 4 cylinder engine. Every 30000 miles I drain the radiator and block, flush with distilled water and refill with a 50/50 mixture of antifreeze and distilled water. After performing this procedure at the 110,000 mile interval the truck began to overheat with the ac on. I live in SC and it happens when the temp is in the high 80's or above. I have replaced the thermostate  the radiator cap, and the senser. I suspected the fan clutch (still do) but when I went to my dealer the parts guy said they never sell any and I would have to special order it. He did say they were constantly replacing the sensers which is why I replaced mine. My hoses are good, that is soft and plyable hot or cold. The belts are tight and don't slip. There are no leaks and there is no indication of water in the oil or vice versa. If the ac is not running  the temp needle stays just a bit below half way no matter how hot it gets. I don't mind replacing parts as long as I'm sure there bad.

It gets to hot here to not have an ac. Anybody out there got any suggestions?

Posted: Jun 06 2008 at 4:30pm | IP Logged

Referance the overheating post from lenny on May 24.

First off thanks for the responses.

I've owned the truck since new and have serviced the radiator with distilled water every 30k miles. It now has 135k. It may have some corrosion in it but I don't think it could have much with the service procedure I perform. As far as air in the system. when I fill the system I bleed it at the top of the block and than again after it reaches operating temp. It may still have air in it but the bleed procedure  plus the number of times I've had the radiator cap off to eyeball the coolant level makes me think that is not the problem. However I'll bleed it again using the "rev the motor method". Also there are a few bugs on the AC condenser but no bent vans

According to the service manaual to check the fan clutch you spin it when cold and than again when hot. The manual says it should spin freely when cold and with some resisitance when hot. I'm not sure how one actually defines those things but this is what I observed. When the fan was cold and I turned the blades there was enough drag on the shaft that it would not move the blades unless I was pushing. When the fan was hot there was way less drag. Now, I woud think for the fan to pull more air threw the radiator there would be a good bit more drag when hot allowing the fan to "bite" more air. After coming to this conclusion, right or wrong, I replaced the fan clutch. Unfortunately the engine still gets hot and the new fan clutch exhibits the same cold and hot characteristics as the original!! Did I say I don't mind replacing parts as long as I know they are bad??!!!

So what say ye boys...stil hot in SC.