heating up stop & go
Melting Slicks
Joined: Sep 2008
Posts: 3,134
Likes: 802
From: Espanola New Mexico
When overheating or running hotter than normal everybody suspects the cooling system, but collapsed or plugged catalytic converters can and will raise engine temperatures. Good to hear that you have resolved your cars higher operating temps.
Thread Starter
Intermediate
Joined: Aug 2020
Posts: 27
Likes: 0
From: Arizona
thanks and yea im kinda surprised that was it well iam assuming thats the only change since the thermostat . Thanks everyone for the help i also saw a fellow c6 owner today waving at me randomly 
Race Director
Joined: Oct 2004
Posts: 12,861
Likes: 4,663
180°? Has your coolant temp sensor been replaced since you were running at 180°? Honestly, I've NEVER seen a stock C5 run at 180°. Mine always ran at 200°+, usually 210-220°, even on the highway. My 2000 C5 owners manual states the t-stat starts opening at 188°. The thermostat has 212° stamped on it, which would jive with what I said earlier, that mine was always between 210-220°. Perhaps it's time for a new sensor.....
Race Director
Joined: Oct 2004
Posts: 12,861
Likes: 4,663
Last edited by grinder11; Sep 2, 2020 at 07:36 PM. Reason: Spelling
Melting Slicks
Joined: Mar 2018
Posts: 2,502
Likes: 187
From: California
Normal and normal for 115 outside ...seizing the road is prob more like 125 ...you know just a side note I had rigged up my outside air temp sensor lower to the ground and on hot days it really reflects a more accurate temp with ground heat ...so for instance if it’s 115 out here I will see 119 ,120 or so inside on the ex read out . I’ve seen higher lol ...and yes the car heats up like a cigarette lighter quick in slow moving or idle traffic with the ac cranked and it will only slightly balance lower off until your in 5th at least this seems to be the magic gear for me even it’s it’s putting around 40-45-50 on hot hot days seems to keep It below 220 I would try using 5th more often and keep the rpms below 3 k shifts ....run it like a slug in that hot weather and save the block ...
Drifting
Joined: Mar 2018
Posts: 1,365
Likes: 414
From: New Jersey
You are absolutely right about a plugged catalytic converter causing high coolent temp and even overheating. Had a car that was overheating while just idling. Changed thermostat and it didn't fix overheating and radiator was good. Proved it was the catalytic converter by just cutting a hole in the pipe just before the CAT and that was enough to lower temperature so that car did not oveheat. Changed catalytic converter and temps when back to normal.
