Cooling Problems
Cooling Problems I have a 1994 Z28 that I recently purchased and I am having some cooling issues. The car will run 185-190 on the hwy, no problem. When I am idling for a minute or more the temperature rises to 220 and above.
I have replaced all three cooling fan relays and the fans will not come on. If I turn on the AC while idling the temp stays at 185-190. If I turn it off the temp goes up fast. Could this problem be my cooling temperature sensor that is located on the driver's side cylinder head, or could it be a cooling fan? 
If one fan is bad, could it stop another one from working? I also plan on flushing the cooling system. Please help me with this because I want to get my new ride fixed so I won't have to worry about it in stop and go traffic.
I have replaced all three cooling fan relays and the fans will not come on. If I turn on the AC while idling the temp stays at 185-190. If I turn it off the temp goes up fast. Could this problem be my cooling temperature sensor that is located on the driver's side cylinder head, or could it be a cooling fan? If one fan is bad, could it stop another one from working? I also plan on flushing the cooling system. Please help me with this because I want to get my new ride fixed so I won't have to worry about it in stop and go traffic. 
On The Tree
Joined: Nov 2003
Posts: 189
Likes: 1
From: South Jersey
I dont remember the exact number but the factory fans do not come on until a really high temperature well above 200 degrees. I dont know how much you have tried but you could make a manual fan switch like described in the basic mods sticky. Good luck if you provide some more info we could help you out more.
The cooling fans will not come on. It doesn't run hot at all when I'm driving on the highway, only when I'm idling. I don't know what to do. The water pump isn't leaking, there is no buildup in the radiator, and I have replaced all three relays in under the hood in the box behind the driver's side headlight. Is there a fuse that controls the radiator fans? If so, where is it located?
TECH Apprentice
Joined: Mar 2004
Posts: 310
Likes: 0
From: Texas
My fans come on when I turn the AC on. Yours fans not coming on at all would make me think that there a fuse blown. Check the relay box under your hood and check the fuses right next to your door. I am going to get a Hypertech 180 and the HPP and program the fans to kick on sonner. I think that past 200 is just too damn hot!!!
On The Tree
Joined: Jan 2004
Posts: 188
Likes: 0
From: Houston/ Austin, TX
It could be your ECT that is under the water pump. Im not sure what sensor that is on the drivers side cylinder bank (under the plugs), but my fans wouldnt turn on either and i replaced the ECT under the water pump and it fixed my fan problem.
I also noticed that my skip shift didnt work with the bad ECT (because skip shift doesnt work until the engine heats up). Hope that helps.
I also noticed that my skip shift didnt work with the bad ECT (because skip shift doesnt work until the engine heats up). Hope that helps.
