Common Threads These Days. Go Here for T-Stat, TB BP, and Summer Cooling

[Idaho Slim]

Seems alot of us has similar problems/issues right now with the summer temps rising, and Spring Maintenance in regards to thermostats, the Throttle Body Bypass MOD, and all the info needed to handle this. I thought it might be a good idea to have all of us post our experiences, and all suggestions here so we can go to one spot for info.

I have another thread going for my performance loss, but my cooling issue is I had my T-stat replaced with the 160 T-stat by a dealer at the same time as I had a cooling flush and re-fill. Now (wether I just now noticed) i see temps soar to 228-230 sitting at idle in about 10 minutes, where as before i dont ever remember seeing these temps. I got it back from the Chev Dealer today after returning it due to this prob. They ran a diagnostic while driving at 70, temp 173 and found the system made correct closed loop and open loop functions. When i drove home tonight, i jumped on the freeway saw temps go to 198 @ 100 mph and then returned to around 184 @ 70 mph, outside ambient temperature is 80. Got home, and got out to open gate, as i parked I saw temps go right to 218 within 2 mins. Is this all normal opereation?? I see where someone posted they rev'd theirs while adding anti-freeze and it statyed right at 173 idling in driveway, noway mine will. My fans kick on as required at 228/230. At first dealer thought problem was because of the new 160 stat, they left it in after running the diagnostic. Am I too critical?
This is on a 96, Auto, Lt-1, w/160 t-stat, no TB bypass. 56,000 miles.
Thanks everyone.:confused

 

[corvette66]

dlkjvthwnehtsaocidutn

My 86 always runs at 230 in traffic, or when it's idling in my driveway. Everyone told me that is normal corvette behavior. I did everything to lower the temps.. took out stat, new water pump, flushed block, new head gaskets, nothing did any good. Runs fine though, have not had any problems with overheating or loss of fluids. ????????

If you figure something out, keeep us posted.

 

[Skant]

It's normal for it to come up around 230 when it's idling. It's designed to do that for the smog test.

Idaho Slim: Your vette has always done that. You just never noticed before. It's not broken. Your 160 degree thermostat doesn't change that behavior at all unless you also reprogram the computer to turn on the aux fan at a lower temperature.

corvette66: It's abnormal for it to read that high while its actually driving. I suspect the gap between your condenser and radiator is clogged with leaves. That would block the air flow and cause it to read high both running and stopped.

- Skant

 

[vader86]

Corvette C4's are designed to run hot from the factory because of emissions.

Coolant temps over 220-230 are normal during city driving in heavy traffic or just idling for some period of time. It should come right down below 200 on the hwy.

Generally, if your stat is opening at the correct temperature (195 for L98, 180 for LT1) and if the space between radiator and condensor is clear, your temps wont get to the alarming stage unless its really hot outside and youre in town.
If you live in the South, its still a problem in light traffic.

If you want a permanent fix, you can do any two of the following and probably never have to worry about it again: Larger radiator, better WP, lower tstat, reset the fans to come on at 200.

Changing to a 160 thermo will reduce your temp average, because it'll take longer to get to 200+ if the stat opens 20-35F earlier, thats the only reason. That reduced mine because I dont spend more than 20-30min in traffic, ever.
Still, once you do go over 210, it can spiral out of control because the radiator is not big enough for the engine. So a fan setting change will definitely solve the problem in tandem with the thermo, but changing to a BeCool, Griffin, etc Radiator (expensive) will do basically the same.

When my 86 ran stock fan and thermo, it got over 230-240 every day in summer in SC. Changing to 160 cut that to about 200-210 (I never stayed in thick traffic long enough for it to get further). Changing the chip to make the fans come on at 195 has kept it under 210 since with the exception of 90+ days with the AC running in Louisiana, where it'll occasionally go over 220.

Some people will gripe about the car needing to get to 212 to boil contaminants, 212 is not a 'magic' temp where everything suddenly gets vaporized, running constantly at 190 for 20min will do the same thing.