uvamosk

Could someone that knows for sure, tell me what average underhood temperatures would be on a civic?

Libertariat

Buy a thermometer?

It's going to be different for every car, ever climate, every driving condition, every driver.

uvamosk

Agreed, I just was hoping someone could give me some ballpark.
I guess i'll just buy a cheap termometer and tape it to my intake pipe lol..

nealnanoHX

Well engine coolant temp is around 210-230 degrees so there is that for a minimum. Exhaust temps can be well over 1000 degrees and higher with boosted motors.

Slow_import

When I still had my 94 integra gsr, I wanted to check and see if propping the back of the hood up served any purpose, so I bought a digital air temp for automotive ac testing off of the snap on guy. Under hood temp was about 130-140 at idle and 120 ish driving around town. The longer you drove it would drop down close to 110. The longer you idled it went close to 150. With the hood propped open in the back, idle temps didn't change much, but cruising temps dropped almost to outside temp. This was done during the summer. Sensor was tested at intake filter and at firewall.

FlewByU352

I've never had my coolant that hot. Most I've done is 203 degrees fahrenheit on a hot day tuning 2 step with no air movement. As soon as the fan kicked on it went down into the 190's and as soon as I started driving it hovered just over 180 degrees. Exhaust temperatures are in the quadruple digits meaning 1XXX degrees but while the vehicle is moving the underhood temperatures shouldn't be anywhere near that. Taking a wild guess while moving the temperature shouldn't be more than 300 degrees close to the header.

nealnanoHX

On a Honda the thermostat is set to open at ~190 and the fans on at ~210, of coarse with Hondata and the like the fans can be set to come on sooner. 190-230 degrees is average operating temp for all gas engines. Under hood temps can very from car to car and season to season. I have never worried myself with under hood temps only coolant temp on oil temp.