Coolant Temp and RPMs
Thread Starter
Heel & Toe
Joined: Jul 2009
Posts: 23
Likes: 1
Coolant Temp and RPMs
In sixth gear at 70 MPH @ 1500 RPM coolant temp goes to 208-210 degrees. Put it in fifth gear and stay at 70 MPH coolant temp goes to 196-198 degrees. Go back to sixth and temp goes up again. I would like to use sixth gear on the highway for mileage reasons and just stay around 196-198 degrees. I just had new belts, water pump, tensioners, harmonic balancer installed. The problem predates these repairs. Any ideas?
Team Owner
Joined: Jul 2006
Posts: 22,190
Likes: 4,178
From: Kannapolis NC
In sixth gear at 70 MPH @ 1500 RPM coolant temp goes to 208-210 degrees. Put it in fifth gear and stay at 70 MPH coolant temp goes to 196-198 degrees. Go back to sixth and temp goes up again. I would like to use sixth gear on the highway for mileage reasons and just stay around 196-198 degrees. I just had new belts, water pump, tensioners, harmonic balancer installed. The problem predates these repairs. Any ideas?
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
You could have tell us some other useful information like where you are living and how hot the air temps were.
I've never seen >200*F on the highway, and that is in days up to about 95*F ambient. But it got close to 200*F on those hot days. On the flip side, I see about 191*F on close to freezing days. So, you can guess your expected temps from those numbers.
I'd expect the rad fins are plugged up so the higher rpms moves more coolant and the car is able to use the few fins that are actually flowing air to keep it cool.
Agreed with above, underdrive pulley yes or no?
Also, 210*F really isn't too hot. The car is fine driving at those temps.
I've never seen >200*F on the highway, and that is in days up to about 95*F ambient. But it got close to 200*F on those hot days. On the flip side, I see about 191*F on close to freezing days. So, you can guess your expected temps from those numbers.
I'd expect the rad fins are plugged up so the higher rpms moves more coolant and the car is able to use the few fins that are actually flowing air to keep it cool.
Agreed with above, underdrive pulley yes or no?
Also, 210*F really isn't too hot. The car is fine driving at those temps.
Racer
Joined: Feb 2004
Posts: 359
Likes: 7
From: St. Paul MN
I agree with the others, that it isn't a problem.
I experienced the same temperatures as the OP after doing a H/C project last winter. I also did a thorough cleaning of the radiator while it was all apart. Generally in cooler weather, 40 to 70 degrees, I noted the same temperatures and quick drop when going to 5th. One time I popped the hood and felt the returning radiator hose was cold while the DIC showed 208. Thermostat must have been closed.
I went to a track day around 80 degrees and never saw the temps above 195 on course, just at idle in the pits. I was not in 6th gear much.
Todd
I experienced the same temperatures as the OP after doing a H/C project last winter. I also did a thorough cleaning of the radiator while it was all apart. Generally in cooler weather, 40 to 70 degrees, I noted the same temperatures and quick drop when going to 5th. One time I popped the hood and felt the returning radiator hose was cold while the DIC showed 208. Thermostat must have been closed.
I went to a track day around 80 degrees and never saw the temps above 195 on course, just at idle in the pits. I was not in 6th gear much.
Todd
