88 C4 radiator fan issue
Thread Starter
Pro
Joined: Jan 2011
Posts: 580
Likes: 8
From: Clemson SC
88 C4 radiator fan issue
I recently bought an 88 Corvette. I just made a 500 mile trip with it (my first long run in it). It typically runs at 175F with 65psi oil pressure when fully warmed up driving down interstate at a legal speed. However, if I then drive into town and have to stop at a few red lights, the temp will quickly go up to about 205F or so while sitting at an idle. It gradually goes back down if I get to 45 mph or so for a few minutes. I am thinking that it may not have a thermostat because it runs a little too cool, but I am also concerned that the radiator fan may not be coming on properly. Can someone tell me at what temp the fan is supposed to switch on/off? Thanks!
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
226 for the Main Fan with the a/c off. 230 psi from the high pressure switch - regardless of Coolant Temp - with the a/c on. Cruise, under most conditions, should be at the thermostat which is 195 (stock). Around town/idle 205 to 212 with the a/c on. At the non a/c threshold, maybe a degree or two above with the a/c off, but dropping below that threshold once the fan is running. You will need a scanner and manifold gage set to check parameters. Your Display doesn't use the ECM signal for fan operation and might be skewed.
Thread Starter
Pro
Joined: Jan 2011
Posts: 580
Likes: 8
From: Clemson SC
Thanks for the info. I finally found several posts on the Forum with similar comments, but without the a/c part. So looks like it is running about right but apparently either has a lower temp thermostat, stuck open one or none so will need to check that, too. Being in the sunny South where it may get over 100F in the summer, I am always wary of overheating issues so wanted to make sure I understand what is expected.
Slingshot
Joined: Dec 2001
Posts: 3,817
Likes: 24
From: Charlotte NC
As SunCr said, the OEM thermostat is 195 degrees. Normal operation has the main fan come on at about 225 and off again at 212. The auxhiliary front fan, if equipped with this option, comes on at 235 degrees.
Many folks have put 180 degree and 160 degree thermostats in C4 L98s trying to get them to run cooler. The car actually is designed to work best at about 195 degrees.
If your car had no thermostat at all it would be running much cooler and also getting poor mileage. I suspect that someone along the way put a 160 degree stat in your car.
FWIW
Many folks have put 180 degree and 160 degree thermostats in C4 L98s trying to get them to run cooler. The car actually is designed to work best at about 195 degrees.
If your car had no thermostat at all it would be running much cooler and also getting poor mileage. I suspect that someone along the way put a 160 degree stat in your car.
FWIW
