Now, I say it is overheating, but it hasn't gone more than 3/4 hot.....still in the white lines.

Only happens with a/c on in 100+ temps.
It seems to just jump up and down. The second I hit the button to cut the compressor, it drops. The same thing in reverse... It did this last summer, only got hotter. It was going to hit the red and I shut the a/c off. I switched to Dexcool, and it is running cooler, but can't really figure out where to go first. The viscous unit in the fan seems to hang on too long sometimes. When the needle jumping happens, the fan is holding. Won't jump when the fan works right. Doesn't seem like the fan spinning too much at idle would make it too hot though. I thought the radiator might have some blockage, but it is fine once the engine gets to RPM and the fan lets go. As I am writing this, I am drawn more and more to replacing the fan clutch. Every variable seems to point to it.

I have a new belt, just changed the 1 yr old one out under warranty. I do not know when the T-stat or water pump were last replaced. I switched to Dexcool this spring, but this problem was happening with more frequency and hotter temps last year.

Just wanted some input. Thanks Guys.

Jason

 

My guess would be the Thermostat.

 

I would change your themostat since its sounds like yours is sticking, have you ever flushed your cooling system ?

 

Well it's always good to write it down as you haveandreflect onit. I think you might be on track with the fan clutch, but I have a gut feeling it's the radiator. Based on what you described and what I've seen on the forum and from my own experience I'm gonna call it the radiator. As you probably know those radiators can clog easily no matter howmanytimes you flush the system. For the hell of it I would look at the weep hole on the water pump and see if it's leaking, although that probably wouldn't be contributing. It's a nasty monkey to have on your back. I got rid of mine after replacing my entire coolant system minus the heater core (it was due @ 70K). I now feel confident I can go anywhere and not worry about overheating. But anyway, I think the radiator is the culprit. Do yourAC fanscome on?

 

Oh ya, I know he's flushed the hell out of it, several times! [sm=lol.gif]

 

Sounds like a thermostat, yo.

 

electric fans are working great. I think I will start with the T-stat. I knew I should have changed it when I did the coolant change over.

I just looked at my belt after work, and the back of it is already shiny. Thought-since the water pump and fan run off the back of this belt, it will make it shiny if it is slipping. Slippage caused by (1) fan pulling too much from clutch not dis-engaging, thus causing water pump to not pump enough through to properly cool the system.or, (2) T-stat closing, causing a restriction for the water pump, making the belt slip. Or a combination of the 2.

This only happens when the air is +100, and there is no rhyme or reason other that the fan is hung up every time. I really don't think the rad is clogged, because it would be constant and happen under certain driving conditions. I could be wrong (known to happen, but don't tell my wife I said that), but I am going to start with the T-stat, and when I get more funds (or the problem gets worse), I will change the clutch.

Thanks for all of your thoughts.

OH...98roverguy, when are you going to get some pics up???

 

Tell me more about your electric fan setup. Where did you buy, which model, pics, how to's, etc. I REALLY want to do this. I installed one in a race car I had about a year ago and loved it. Need more info on this for the Disco II.

Thanks

 

Ya the t-stat is the quickest and cheapest place to start. I do have a couple pictures I think I could post, so maybe I'll get on that!

 

Actually I think he's referring to the factory installed AC electric fans.