Hot light

[Paul G]

Determining how hot is too hot has been many a topic for discussion. So I was thinking.... at what engine temp did Ma Mopar turn on the hot light? That would probably be a pretty good gauge of what temp is too hot.

We took a ride up to Sedona today in the Corvette. It normally runs around 190 or so. Pulling up hill with the A/C on the engine temp got to 235 and was quite happy at that temp. The red area of the analog temp gauge was 3 hash marks away yet. If my 72 Charger gets to 225 I start looking for a place to pull over. Maybe 225 is an acceptable temp to run at?   

[doctor4766]

Yeah good question

[A383Wing]

the newer cars can take the higher temp...some cars run over 200 all the time...225 would make me pull over as well on the older engines

some of the GM cars don't turn the radiator cooling fan on until 235*....a little too warm for me

[John_Kunkel]

I had a '67 New Yorker that didn't have a coolant temp gauge, only a warning light and it was triggered at 240°F. The light would never come on during normal operation (even in traffic with the A/C running) but if you shut it off, waited a few seconds and turned the key back on the light would be on. This tells me that it was running in the high 230's and the short heat soak brought it up to 240.

As far as what's "too hot", depends on the pressure cap...as long as the cap holds enough pressure to prevent boiling it isn't too hot.