The engine is running (excessively) hot when I have on the ac but! The weirdest thing is that it blow hot air until I put the van into neutral and rev the engine to 1,500 to 2,000 RPM. I used to be able to run Max AC all day everyday with the temperature being only 210 to a little over. Now it is running not red, but the line right before red on the gauge... I did a coolant fluid exchange about 4 months ago and it fixed the problem until a few days ago... IDK if it is the almost 90 F temperatures outside or not (it didn't seem to act this way before), but this has me a bit worried. (The mileage is currently 59xxx at the moment. Not sure if that helps.)

 

Hhhmmm..... I would suspect you were still low on coolant, or, the fan clutch has failed. Also, the a/c system may be in need of a recharge.

 

The fan cools both the engine and the AC condenser. If the problem only exists at idle or city driving and not on the highway, then I suspect the fan clutch is slipping and the fan is not turning as fast as it should.

 

My apologies, It won't blow hot air. I was really tired when I made the post. It seems to exist less on the highway but I also drive at higher RPM's on the highway. (Even on max heat is seems that the engine just wants to blow cold air unless I nudge it with neutral revving as I have described earlier). The problem also seems to be getting worse. (As an the neutral revving doesn't seem to be working as fast or as effectively, in some cases both.)

One other thing, the overflow is full, but I don't know if the radiator itself is "full" so to speak. (How advisable is it to put some coolant into the radiator itself to see if that fixes or at least delays the problem???)

Sorry again about the late response!

 

Is the water pump old or new?

 

Probably as old as the Van! (or it was replaced according to schedule, the van used to be an airline van) The van won't blow hot air UNLESS (for the most part) I have the engine revved around 1500 to 2500 rpm (rough estimate). The only way currently to keep it from getting dangerously close to overheating (according to the gauge) is to keep the van in 1 gear and two gear and drive at a relatively lower speed so I can keep the RPM up...

 

I have seen water pumps where the impellers are broken or deteriorated to the point that it can't pump coolant fast enough.

 

An update on this, I got a coolant flush a month back and it seems to have fixed the problem at least for now. (If history tells me anything it will pop back up in a couple of month).