Omar23109

I have a 1999 camaro ss with the stock ls1 in it and that motor has about 109000 miles. Recently it has started overheating, however it only does this when I am either at idle or driving in the city. The car runs at normal temperature while driving on the freeways at 65 MPH. It seems like when lm driving in the city and I get on the gas around 3/4 or full throttle it drops back down. Anyone have this issue or know what needs to be replaced? All I have so far is the basic start swapping stuff but a more detailed response would be appreciated. Thank you for your response in advance.

LS6427

iTrader: (2)

Most likely your fan(s) are not coming on when you are driving in the city or in stop and go traffic.

Next time its up to operating temp......turn your A/C to MAX and pop the hood to see if BOTH fans are "ON". If they aren't......check the relays in the fuse box right behind the drivers side head light. The big square grey fuses. You'll have to swap them with other ones to try....or get new ones to try. Because you can't tell if they're blown by looking at them.

Fans keep you cool in city driving.......on the highway they are not used for cooling.

.

RPM WS6

iTrader: (3)

I agree to start by verifying that the fans are operational, since that would be essential to proper cooling system operation at idle and low speeds.

But if it cools down quickly with application of heavy throttle even at city speeds, there may be an issue with coolant circulation (such as a sloppy pump or blockage in the radiator, etc.) Or this just may be the result of more air moving accross the radiator as your speed increases, if the fans aren't working.

Does the coolant look clean? Any wobble in the water pump pulley?

lq9transam

I am also having over heating problems, i have a 2002 transam with PRC ls6 heads, 233/239 cam, forged mahle pistons, 92mm throttle body with fast intake, underdriven pulley. ive replaced my radiator, water pump, thermostat, and cleaned my coninser. it overheats when i get in the throttle a little too much, when i do it blows the fluid out of the coolant tank and also blows the lid off.
I am seriously stuck and need advice as to what could possibly be causing my problem. any advice would be much appreciated.

azvette89

I am having the exact same problem with my 99 vette.
I believe the culprit is the fans so i ran some wires from the right side fan to a toggle switch. It worked for a few hours then the toggle switch i put smoked a bit and stopped working.