Alright, I posted erlier that my truck was getting hot when I was running the a/c. After checking some stuff that a few people suggested I decided to drive it today with no a/c. The temp spike still accured. The strange part is that it happens at higher speeds (around 55-65) and cools down at lower stop and go speeds. Now this doesn't make alot of sense to me being that the faster your going more air SHOULD be passing throught your radiator. Right? So, could it be a t-stat problem or maybe the clutch is out on my fan? I don't have a clue. Any thoughts?

 

sounds like your rad is blocked or there is blockage in your cooling system... I'd flush the motor & cooling system real good then go from there. a flush is cheep if you do it yourself. I'd recommend going this route...

drain system, fill with tap water, run it to opp temp, then drain again. repeat until water comes out clear (may take several times to get it to come out clean) THEN use the flush additive and follow their directions. once you drain it out, repeat the 1st steps I mentioned... flush, drain, flush, drain etc until it once again comes out clean.

Once your happy the block and rad are clean, I highly recommend using distilled water & the 5 year coolant (orange). If you use tap water, you MAY develop sludge again in the system. I did when I did some cooling system work and just filled with tap water for a short time. 6~8 weeks and I had sludge developing again, had to flush it again [:@]

 

Thanks Steve I'll give that a try.

 

I've been overheating as well, and with similar symptoms (have a complete thread devoted to it 3 pages in length). Turned out the radiator cap was faulty.

 

I think steve pretty much hit it on the head, check your radiator, or hoses.

 

Gary, when your rad cap was faulty, were you loosing coolant as well? should have been since there was no seal on it.

 

Check out my conclusion here. Yes, I was always blowing coolant.

 

I don't know if it's my cap because there are no signs of coolant leaking anywhere.

 

Then you most likely have a blockage; however, I would strongly recommend AGAINST using DexCool in your truck. GM and Chrysler/Dodge both suffered from using that in certain vehicles. I know GM took it in the shorts when they tried it in the S10 series vehicles. It ate some of the innards of engines; however, my 2002 Cavalier has been running it for 6 years/143K miles with no issues.

Assuming you want to attempt to use it, the system has to be thoroughly flushed, because orange and green don't mix well.

 

Flushed the system today and that wasn't the problem. Next step is the t-stat. And if that doesn't work then I geuss I'll try the fan. On pavementsucks.com's tech page he shows how to change the clutch on the fan. He stated that he had to change it after he started to have temp spikes and that is similar to the syptoms I'am having. Any other ideas before I take this thing to the shop?