240 is a little warm - probably just need to clean the radiator.

 

a guy i know said they collect debrie . front lower part of rad . take out and have shop clean inside and out .......... mabey thats the prob. .... or did you get it fixed ?

 

I would check a number of things.

1.) These cars are like vacuum cleaners. Debris gets sucked up and can clog up the fins in the radiator. Some claim you can clean it out without removing the radiator, but I would take it out and thoroughly clean it with a powerwasher. Don't worry, just spray it directly at it, and it shouldn't hurt the fins.
2.) While you have the radiator out, I would take it to a radiator shop and have them clean out the core. They'll pop off one of the side tanks and run a bar through each horizontal tube. Half of mine on my 94 Corvette were clogged with gunk. That made a NIGHT/DAY difference. Like a 30-50* difference. You car is 18 years old now. There's no telling what kind of gunk has accumulated in the water jacket. Having this procedure done is a cheaper than spending $150-200 on a new radiator. I think it cost me about $60 to have mine cleaned out. See # 5 also, or you'll just end up at square one in no time.
3.) Replace the pressure cap. They do wear out, and if the spring has softened up a bit, some of the coolant can boil out. So if you noticed that the coolant level drops over time, but theres no antifreeze on the garage floor, this could be it.
4.) I doubt this is it, but you could replace the T-stat. T-stat will only regulate the lower end of the temp operating range. If won't prevent your car from overheating.
5.) Flush the coolant out and do it thoroughly when you clean out the radiator. That means removing the knock sensors, removing the t-state, and running a hose through the system. You want to get EVERYTHING out. Like previous posters said, use the green stuff. You don't ever want to mix the green and orange. It'll turn into a jello like substance that will be really bad. Do this especially if you get a new radiator.
6.) Make sure the cooling fans are working properly. Without the A/C on, they would come on at around 228 and 238. These cars were designed to run a little hot, but 240 is about as hot as I'd feel comfortable letting you car get.


Number 2 made the biggest difference for me.

 

I drained and flushed the system and replaced the thermostat last night. I bailed out on pulling the knock sensors. Coolant was brownish, flushed until clean water came out. CHecked the radiator for debris-clean except for one large Sycamore leaf floating around, I purged the air out and will give it a good test today as temp is expected to be 96 today here in south Louisiana. So far I let it idle for 5 minutes and the temp only went to 165 with the A/C off. I'm hopeful the purge and stat have solved this problem and thanks for the helpful input from all of you. My next project is to replace the turn signal switch and that does not appear to be an easy one but I did find excellent instructions on it through this forum.

 

Just made a Test Run in the 95 degree day and 217 was the max temp I saw sitting, running in the driveway. Thats a big improvement from 240 and climbing! The coolant flush did help, I tested the old thermostat in a pot of hot water and it still opens at 180. Many thanks for all the helpful input on this.

 

 

Thats better!
Mine will get over 210 at the track even with the fans turning on at 180 and the big old dewitts radiator. But that is 95 ambient air and after 15 min at 3 - 6k rpm.

 

After a very hot day at the track, I came back, flushed my radiator, cleaned up the fins, and started to use Waterwetter from Redline...even after a hard run, the car is way below 220, in fact, at times, it seems to run way too cold....that waterwetter is amazing!

 

i will have to remember this. ha.

 

My analog was reading 240 when fan kicked on after scan found fan kick on at around 220 the gauge is off by 20plus degrees so take some temp readings before you spend a bunch off money

 

Good point Kevman. Watching that Analog will freak you out when it starts to peg. Especially in traffic when you know you can't get up to speed and cool the beast down.
I'm going to run it some more today and see what happens, fingers crossed. Nothing worse than a car that overheats.

 

Keep in mind that analog gauge does not have a linear scale.
So, most of the time you can't really tell what temp its reading.

In stop and go traffic, the needle is going to be very close to the upper limit before the cooling fans come on.

Did you needle really "peg"?
Look close at the gauge again, and you should notice the needle not quite into the "shaded" area.
It's not 260 unless the needle is pegged to the stop.