1993 40th Anniversary C4
Engine: 350 - UNmodified

Noticed on the instrument panel the analog gauge reads 180F but digital reads 220+F... After research, I came to the general concensus that the vette is supposed to run hot from 212F up to 230F and I have problem with my engine running above boiling. If this necessary high temp is normal, can someone tell me why the engine needs to run that hot? Next...what are the thoughts on wiring the cooling fans direct into ignition. I did this on my camaro (lt1) and put in a 180F thermostat and this corrected the overheating problem. And what is the normal operating temp for oil? Reason is my analog and digital gauges are giving me different readings...

Thank you for your time...

IsleGirl

 

I was freaked out seeing the temp so high on my 93. Especially in traffic here in Texas. 205 was the norm when cruising and 230+ in city traffic and drive thru's. 2 years ago I swapped out the stock T stat for a 180 and got a tune from PCM4less that brings the fans on at 190. I drained and flushed the radiator and installed a new coolant temp sensor. Now 185 on the freeway is norm and 203 is the highest I've seen in city driving. I like the tune better than the hotwire method because I see no sense in running the fans when not needed on the highway or loading down the charging system.

An after thought.
I guess if you wired a toggle switch in and brought the fans on when you wanted and could turn them off on command that would work too.

 

When the A/C is on the fans will be on.My 95 runs on highway 197 to 205.I have a stock system except for a Dewitt's radiator(3 rows) in traffic it will climb until fans kick in.

 

This has a reverse cooling system so you must get the correct thermostat for your car. My 95 stock is a 180 stat.Make sure all the junk is cleaned from the radiator because these cars are like vacuum cleaners and the radiator collects alot of debris from the road.

 

The primary reason C4's run "hot" is for reducing exhaust emissions. The cooling system was designed by GM for that purpose.

The analog gauge is not "linear" in that as the needle moves toward the higher values, it will travel a shorter distance. Look at the spacing between the values, there is much less space between the marks on the higher temp side compared to the low temp marks. Sometimes the analog gauge can even be off by anywhere from 10 to 50 degrees. The digital temp display is much more accurate.

For oil temps, expect them to be 10-30 degrees hotter than coolant temps. One of the reasons GM went to Mobil-1 synthetic oil is that synthetic oils can handle higher temps much better than regular "dino" oils. As long as you use a full synthetic oil that meets the GM 4718-M standard, oil temps even as high as 280+ will not be an issue. Most of the full synthetics out today meet the GM Dexos requirements; they will be fine too.

Have you done a cooling system service lately? You 93 uses the "green" ethlyene-glycol coolant and it's a good idea to do a service every couple of years. Also check for dirt and debris that may be blocking airflow into the A/C condenser and radiator. Clean that out and you may see a drop in temps by as much as 20 degrees. Are the radiator hoses original to the car? If the lower hose is weak, it's possible that it's collapsing and reducing the coolant flow.

I'm not really a believer of manual fan operation; if the cooling system is in good condition, there is no real reason for an override. Turning on the A/C results in running both fans. That alone can cut coolant temps.

 

Also, remember that the cooling system is under pressure, so temps above 212 do not indicate boiling. The higher-than-ambient pressure allows your coolant to function at a non-boiling state; you can google and find a chart that correlates pressure to boiling point.

 

w/c4 cruiser on temps for emissions
I think its way to friggin high at least for my tastes bakes every gasket and plastic plug under th ehood.

Rather than hacking up your wiriing have it reprogrammed so the fans come on/off when you want. Having the fans on when the motor is cold doesnt do anything excpet extend warmup time and wear the fan motors out.