Mike,
I had just installed a coolant fan switch. It is tied to both fans. This was purchased from Ecker's. p/n 40290. So, the switch does made the fans come on at 200. This was the highest cut-off switch. Do you think that the fans running all the time is OK ?
Of course they are off during cold start... I know this is normal.

 

No. Lots of unnecessary wear and tear on the fan motors. My fan comes on at 205 and off at 195. It only runs in stop and go traffic and even then only intermittently.

RACE ON!!!

 

You could also add a bottle of Redline Waterwetter or similar product. It should drop the temp almost 10 degrees.

 

I have to agree with CFI-EFI, that is probably too much use of the aux. fan. Could lead to premature failure of the fan. Remember that GM built the C4 assuming that the aux. fan was the last fan to turn on. It isn't expected to be used as much as the main fan and definately not allthe time.

As I posted before, the GM Factory specs for the 88:
Main fan should turn on when coolant temp reaches 226F or 108C. (page 6E3-C12-4)
Aux. fan should turn on at 228F or 109C. (page 8A-31-1)

GM designed the C4/L98 with a target of operating range of 195~225F with no fans running. (A/C operation being the exception). So, your car is operating as designed and not overly hot. As long as you are below 230 you should be just fine.

If it were me, I'd restore the original factory aux. fan switch until a better on was available. Check with MidAmerica or try finding the manufacturer of the one you have and see if they make one with a different temp range. I got mine from MidAm and it is on at 205 off at 195. Pull and really clean the radiator and radiator area. This is a relatively easy one morning job and makes a HUGE difference.

You can also increase the ability of the coolant to carry heat by lowering the percentage of anti-freeze to water. Anti-freeze increases the temp range at which coolant boils/freezes, but it also slightly lowers the specific heat carrying ability of the coolent mixture. If your climate supports it, drop the anti-freeze percentage to 30% or so. You won't be protected to -50F but maybe you don't need that much freeze protection. Never run with no anti-freeze because it protects internal water pump parts, helps prevent boil-over, and helps prevent electrolysis between the aluminum heads and iron block.

 

My vette is a 95 w/ LT1 . Does it make a difference on operating temp ? I know that you though that I was talking about the L98.

 

The '95 is a little different. Both fans are controlled by the ECM which based on the electrical signal from the Coolant Temp Sensor will ground the main fan relay at 219 - off at 207; the secondary at 228 - off at 217. If the a/c is on, the ECM ignores the temp signal and grounds both fans based on the signal from the a/c pressure switch.

On either model, the temp gage has nothing to do with fan operation. Hooking up a scanner is the best way to verify the ECM signal (primary fan operation only for the L98).

The booster fan on an L98 should rarely if ever come on and was more marketing hype than a primary source of cooling the engine. If it is coming on a regular basis, then there may be some other cooling system problem and without an alternator upgrade, it adds substantially to the electrical load at idle. Once the amps are gone, the fans are going to slow down and the temps will go up.

There is nothing unique about a Vette's operating temps - all modern computer controlled engines operate at these temps, but few have a gage giving the operator the exact coolant temp.

 

On the 95 LT1 - Both fans come ON at 228. From what I hear... this is normal.