Just checking in with you all. I have 21 HTC Z51 all stock. Just picked it up a week ago. I live in East TN and temperatures are pleasant currently. Maybe 82-83 daily. While driving the C8, and not driving it hard, I’m noticing while moving the engine temp is 172-175 deg.F. As soon as I stop at a light or traffic it goes up to high 190’s to 205. Then back down under way. Are you all seeing this in your Vette as well? Thanks!

 

I'm guessing that by engine temp you meant the info given in the lower left---Water Temp---?

Mine runs 165° to 172° in 80°+ ambient down the freeway and will warm up to 175° at idle. ... Mine seems to run particularly cool tho as compared to others. More will weigh in.

 

2022 C8 LT3 HTC and here in Central Florida the air temperatures have been in the low 90's during the day for weeks and yesterday I was stuck in several traffic backups. As soon as I hit the backups the engine temps went to 195-205 range and stayed there until I got moving, but never above.

 

Ditto.. Water temp 178F on highway.. up to 205F when going very slow, or at a long stop light. 2021 Z51 HTC. Seems normal to me.

 

^^^
Mine is typically 178 to 180. Will go to 185 BUT have not seen it over. But my rural driving has few red lights. But what is referred to as "5 Points" near the town center (has 3 intersecting roads so really 6) occasionally have to wait 2 long lights. Never have seen the temp rise past 185 F. Actually, I avoid that intersection best I can so can't say that two light wait was very often.

Wonder if some with Verts have their AC on full blast with top town. My Coupe never has the roof off or windows down!

 

Thanks for the reply’s. Good stuff. Don’t remember my C7 being this way so just thought I’d check with you all.

 

Have never seen mine over 195 and that includes the last couple weeks in Southern California when temperatures were well above 100 (107 was the highest I witnessed) and idling in bumper-to-bumper traffic for over an hour on a Labor Day weekend drive.

 

Two things - the car needs airflow to cool itself. Not moving willincrease the temps. Second, those temps are well within normal ranges.

 

My C8 cruises at ~180 max I have ever seen is 192*

 

the stock thermostat is 70* C = 158* F

 

My guess and it is only a guess, the HTC's might run a little warmer than the coups. My 2021 coup is just like JerryU's coup, it runs between 178-180 nothing over 185.

 

I am from the Tri-Cities in East Tennessee. About 90 miles from you. I have a coupe and the Temp stays around 175-180 all the time.

 

One could compare the surface area of the vent screens on the coupe (are there 6 of them?), with the surface area of the vent screen in the tonneau cover. I don't know if that would be the only factor, but the HTC vent opening is pretty large.

 

In my 2021 Z51 HTC and in normal driving I see temps up to 185, even with the top down. Only time I saw 200 was in the summer when I was on a mountain run and made the ascent up the road to Brasstown Bald in mostly 2nd gear, towards the top. I will keep a closer eye and report if I see higher temps. I have the aftermarket Attack Blue Filter, custom grill guards up front, no aftermarket exhaust, currently at around 7300 miles and the first year service was done around 6100 mileage. I do not run the AC with the top down.

 

Where did you get that data from? I believe the thermostat is far higher than that. Modern cars run at higher temps than they used to for better emissions control.

 

1. the temps inside the engine compartment have little to do with coolant temps. Coolant temps are controlled by the radiators and thermostat.
2. At the HTC reveal, Tadge said it was easier to control engine compartment temps in the convertible than in the coupe.

 

I searched the 2020 service manual for some indication of coolant temperature range. I found the following that indicates that the thermostat should start to open at 188 degree F, and should be fully open at 206 degree F. There are multiple coolant flow paths, and a search for thermostat replacement reveals at least three different thermostats in the cooling system:

1, Radiator Inlet Hose to Auxiliary Radiator Inlet Pipe (this one only appear in the illustrations for option code V09, cooling system, powertrain, high ambient, which includes an extra radiator on left rear, which is not on US models).
2. Auxiliary Radiator Inlet Hose to Auxiliary Radiator Inlet Hose (this one appears in the illustration for the right rear system, option codes "V08 and V09" - I believe it is included with the Z51 option which adds the "rear-mounted third radiator")
3. At Engine Coolant Manifold (this is the conventional looking thermostat at the water pump inlet, I think).

I only found one discussion of thermostat testing - I believe it applies only to testing of the conventional look thermostat that resided in the inlet housing on the water pump.

So, how can we have lower operating temperatures than 188 degrees? Most thermostats have a small hole in them that allow coolant to flow even with fully closed. This is necessary to allow the warm water to get to the thermostat so it can eventually open. So coolant is actually flowing. The oil can be checked when coolant temp reaches 175 degrees according to the manual.

Anyway, this should provide a clue to the normal operating range for the engine coolant. I could not find anything that indicated the temperature at which the actual overheat message happens.

 

https://parts-catalog.acdelco.com/acesCat.php?
that you stated is true, LT1's stat are 194* but if you do a search here for a OEM 2020-2022 thermostat, you will see in one of the pix of the stat it clearly has a marking of 70*C. i am sure that is why some folks are reporting cruising temp in the mid 160's. from a cold start, go right on the freeway (easy driving), the first sign of coolant temp dips, that would also give you a clue what the stock stat is rated at without taking it out.

 

Here is the search result. I can't make out the number stamped on it - but 70 deg C is lower than what is stated in the 2020 Service Manual, as posted above.

 

flip the picture upside down the 70* will be obvious. that is what i did. i think from what was posted on the service manual it doesn't give the temp that is rated at. let me see if i can post a better pix