Now that it’s getting hotter outside I notice that my engine is running hotter during the day than it does at night. I’ll drive it for about 30 minutes or so in the late afternoon and by the time I get to my destination I notice that the temp gauge is well past where I would want it to be. I have used an IR temp gun and it reads close to 220 degrees. When I run the car at night, same distance and time, the temp reads pretty darn close to 195 degrees.

What I’ve done leading up to this:
- adjusted the air dam/front spoiler
- foam seals are in place though some gaps
- replaced fan clutch
- replaced lower hose
- replaced thermostat (195 installed)
- replaced water pump
- replaced rad cap
- replaced coolant with 50/50 after flushing
- set timing to 6 degrees BTDC with EST wire unplugged


while I have set the timing, it’s purely based on the mark of the balancer. Is there a way to tell if the balancer has slipped? I know the easiest way would be to uninstall it. Before I go and do that, is there something I can do without having to uninstall a bunch of stuff? I’m tempted to just replace it as I have no idea how old the balancer is, if I had to guess I’d say it’s as old as the car and likely needs replacing but I also don’t want to just throw parts.

If it were timing related, wouldn’t the car still get hot when driving it when it’s cooler outside? Or would the cooler air be enough to cool it enough despite the timing?

 

You made no mention of actual air temperature. 220 in very hot weather with AC running and a 195 thermostat is not a problem.
The auxillary electric fan comes on at 238.

 

From your description, it sounds like everything is working as it should. Changing your thermostat is not really a good idea, because the ECM wants the temp to be above 190* before the computer will operate in normal mode. Also, changing the thermostat will NOT really affect running temperature once the engine is fully warmed up. It only sets the MINIMUM operating temperature of the engine (for faster warm ups).
It is not unusual for the engine operating temps to be a bit higher during hot weather than when it is cooler outside. I suspect that your radiator just has some "lime" deposits on the cooling fins (inside the radiator) which is causing the radiator to be less efficient than when it was new. A simple thing to do would be to run some radiator CLEANER (not radiator FLUSH) through the radiator [per instructions on the bottle] to eliminate any deposit build-up on the fins. If you have not done this since you have owned this vehicle, you should do this first to see if you make a significant improvement in your cooling system's performance. The only expense will be the bottle of radiator CLEANER, a gallon of [undiluted] anti-freeze, and a gallon of distilled water (get at any grocery store).

 

It's usually around 95+ degrees during the time of the day that I'm driving it, at least in the summer time. Then dips down to mid to low 80's in the evening.

I'll give that a try. I did not realize that there was a difference between radiator cleaner and flush. Are there any recommended brands? I used the Prestone Flush and Cleaner but I only followed the steps for the light cleaning which only ran it for 10 minutes and then drained and filled from there. One that pops up then I search for radiator cleaner is Liqui Molly.

 

Sounds like you have changed everything but the radiator and heater core. I would just replace the radiator with a good brand since you are in the mood of spending money and it should be OK since there really isn't anything left.

 

There is nothing wrong with 220 on a 95+ degree day.

 

Definitely not in the mood to spend the kind of money to replace a radiator. Back in 2022 the radiator was replaced by the previous owner with an X2213 which from searching different sites is $420+ so yeah, not looking to spend that kind of money right now.

 

Thanks! I'm just being cautious especially since I had other heating issues with it. Last thing I want is for it to be overheating and causing other issues. I'm also not used to an older vehicle. For reference my other ride is a 2012 minivan and the temp doesn't rise up significantly so going from that to the 'Vette it's just a little concerning, but if that's how it's supposed to be then I can live with that.

 

I believe you can buy a temp switch that will turn the fan on at a lower temp.

 

If this stuff doesn't get the scale out, then your next step is a new radiator, assuming you don't have a radiator shop in your area that can disassemble and "rod out" your core.

https://www.grainger.com/product/CLR...-Bucket-56DY61