Running hot

[Jonasterg]

Now that it's summer, my car is starting to run hot. 160* thermostat, if the car is just idling it will heat up to 210* or so. This is w/o blowing A/C. I'm gonna change the radiator fluid later this week, and finish doing the spring cleaning. I'm thinking it might be a bad thermostat, or maybe clogged radiator? All the fans are coming on correctly, no fuses are blown. Any suggestions on where to start looking? I'm home from college for the summer, so I can finally get my hands dirty working on my T. Thanks in advance for any help.

 

[striker_29]

Jonasterg, I am having the exact same problems with my car you need to get that fixed. Its not good on these cars to run that hot. Definately change the thermostat for 5 bucks. If you have the orginal radiator, its probably worn out. You may want to check on getting a heavy duty 3 core radiator. There is also an additive called RMI-25 that is supoosed to be really good stuff, I just orered some yesterday so I cant say for sure. You can check it and the radiator out here:

http://www.arizonagn.com/cooling_systems.htm

HTH and good luck...Mark

 

[dgreene]

Jon, I would check the thermostat first, but sounds like you may have a clogged radiator. You didn't mention it, but does the cooling fan come on at idle when it gets that hot? What temp. does the chip have the low speed fan kick on at?

 

[WarpSpeed]

Even though these cars are getting old, I wouldn't expect a clogged radiator to cause that unless it's really clogged, more likely the thermostat is stuck or something, or the water pump is not working right.

 

[Jonasterg]

I'm gonna get a new thermostat first, and see if that helps. When it's moving, the car goes down to ~180* but not below that. When I get stuck in traffic, the temp keeps rising. The fans all come on like they should, all the fuses are complete. I'm not sure what speed the fan comes on at, I'll check the sheet that came with the chip to see. (Casper's Ultra chip, 7 position thumbwheel.) I'm hoping it's just the thermostat, I'm gonna pick up a new one tomorrow and see if that helps. Then I need to finish the spring cleaning, and see how the car runs. Thanks for the help, we'll see what happens tomorrow.

 

[Weazel]

Jon, I have the same thing going on with my car (either that or a hosed up water temp gauge). I put some Prestone Superflush stuff through the radiator (after draining the coolant from the rad. and the block). I got some very noticable particles out've the radiator. It's still running hotter than I'd like (200ish), but it's cooler than it was. I believe it has the stock thermostat.
My car behaves the same as yours (fan comes on and everything). I was gonna take it to the shop and ask them JUST to replace the thermostat. If you get it done before I do, can you post the results (or PM me?) Thanks and good luck! I'll let you know if I figure out what's up with my car.

 

[terryk]

You folks *really* worry about 200F? That's just getting warmed up.

I'd worry at 240F+. If these engines are that fragile, we own the wrong cars.

I understand the power implications, but 200F is nothing from a reliability standpoint.

 

[dgreene]

The reason I suggested the radiator is I have tried flushing my radiator and I dropped my temps as well. I have a new 160 and the chip is set to come on at 165 and off at 160 but at idle before the flush the temp would just keep going up till it hit around 220. After the flush(during cool weather) it would only go to 170. Now that it's warmer, it is going back up higher. I had the same problem on my 87' Formula 350 and a new radiator put the temp back down to staying 170 even during the summer(95-98 degree days). I'm gonna have the radiator recored on the GN and I will let you know my results.

I agree with the above statement, 200 won't hurt anything except power.

 

[Steve Wood]

Core is probably full of scale from the antifreeze and the core is also losing efficiency as the bond deteriorates between the fins and the tubes.

Try the thermostat first, and while the coolant level is down, pull the cap off the radiator and look at the ends of the tubes and see if they have deposits in them. Almost impossible to get a cleaner that will remove them and leave a radiator behind.