If its overheating at idle, check the fan clutch and make sure its not free spinning once the engine is up to temp. There should be some resistance. If you try to spin it with your hand it should only be able to spin about a half turn after letting go.

Also, replace the cap and get that out of the way.

 

so. update. I attempted to do a pressure test but the tester i rented from the auto parts store did not have the correct connection to fit the cap...so took that back and got home and started thinking,.... which the lady of the house tells me i should not do that.,maybe i did not put that electric fan in correctly? Behold,it was not pushing the air correctly.i did the paper towel trick i read about on this forum in the coolant issues thread written by savannah buzz, much appreciated by the way, do you think that could be the overheating problem? I flushed and refilled the radiator as well today.

 

The electric fan only comes on when it's on the verge of overheating. So, it will help, but it's not the problem.

Are you running dexcool (orange coolant)?

How much coolant are you having to add every 4 days?

Is it overheating because it's low on coolant?

 

Nope, the fan comes on at other times, not 100% of the time with AC (like a D1 does), but under certain conditions, such as speed under 50 mph and air temp above 81F. If those conditions happened when you where stopped, the electric fan and the viscous fan fight each other. The radiator just does not have enough air going by. Once you are up to 60 mph you have 5280 feet per minute of air speed, fan is not much of an impact. But there are lots of things to cause overheating, and it is not uncommon to have more than 1.

 

It still overheats when its full on coolant,after i did the flush tonight i drove it around and it overheated on me again,it started when i was sitting at a light,if i let it sit at idle in park it never overheats,and it doesnt always do it when im driving and im sitting at idle. the viscous fan does have a chip in one of the blades,but i dont know if thats the problem.the fan clutch seems to be in good shape after i tested it when shutting it off.ive replaced the t-stat a couple of months ago but i dunno if i should replace it again.Maybe water pump?I dont want to throw money away either.I also noticed alot of coolant on the chassis under the reserve tank vent hose after i shut it off.Im not really adding much fluid at all every four days,mainly just topping it off.I am not running dexcool

 

Have you put in a new coolant cap? Old one could be venting at say 6 pounds, instead of spec 18 PSI. That would vent coolant when driving. You can zip tie a paper towel to the vent hose to prove this issue.

Radiator should be an even temp, top to bottom, on the fins. When sludge forms, the lower rows are much cooler, like 10F or more diffeence.

 

I have not replaced the cap.But could that be the cause of overheating?

 

I stand corrected! I'll have to read up on the electric fan.

I wouldn't replace the new thermo, and usually water pumps leak when they are failing. I'm starting to suspect your radiator, but I'll be curious what buzz/mike/spike think. Rads are notorius for getting clogged in the D2. They can be gotten fairly cheaply, but the job can apparently be a pain in the ***. Search this forum for discussions about radiator replacement.

The leak could be your rad cap, but also in that area it could be a leak in of the hoses. Those hard plastic hoses get very brittle and develop cracks, so check them carefully and be very gentle or you'll break them.

 

Yes, for two reasons. First, it normally vents at 18 PSI. The cooling system is pressurized, and that raises the boiling point of water. Second, if the seal is eaten up by something like Dexcool, it will vent at a lower pressure. So it can squirt out coolant as you motor down the road, but may not drip in the driveway. One way to check for coolant loss this way is to zip tie a paper towel to the end of the overflow tube.

But it may not be the only cause, here are some of my favorites:

Radiator, oil cooler(s) and AC condenser caked with mud, leaves, trash.

AC fan siezed, fuse blown, relay bad, or wired to run backwards.

Serpantine belt routed wrong and water pump runs backwards.

Fan mounted reversed and blows air out the front grille against a paper towel instead of sucking it toward block.

Radiator internally clogged with scale or Dexmud, will be cooler on bottom fins by 10F or more.

Water pump leaking

Fan clutch spins 1 revolution or more when spun by hand and released after engine warmed and shut off. Freewheeling means no fluid inside clutch, so no power coupling.

Center area of radiator low air flow. Front of fan clutch has to get warm to come back to full power coupling.

Any hose clamp any time

Throttle body heater gasket

Main thermostat old (with sludge inside the top metering holes), or replaced before final flush out and repair work was done.

Head gaskets (there is a chemical test for exhaust gas in coolant)

Cracked block

Cracked head

 

Today I replaced the cap, drove it around for awhile, then I drove it to work, never over heating, I hope that it fixes my issues,.. but It would be bad if I spent so much time and money and frustrations on something that was a 16 dollar fix from auto zone in about 10 min