Overheating

After 20 years with no issues my V6 2003 started having issues on a roadtrip.

Filling it with coolant from time to time got me all the way home. As long as I was moving it was fine

Then I had it in a shop for a pressure test and a flush. There were no leaks but the fan clutch was replaced.

this seemed fine until I took it out today, after a 1.5 hour drive it started getting hot again, then it had a full boil over and was staying hot. It dropped into normal range a couple times but finally got hot enough that I pulled over and am waiting for a tow right now

The water pump has been replaced in its lifetime, but the radiator has not. I also noticed it getting much cooler than it should be when not under load, like a bad thermostat or something

should I go ahead and replace the whole radiator or could this be a thermostat problem? It takes literal hours of driving to recreate the problem.

 

Replace the thermostat and see if that works?

The thing that opens and closes to let's water flow through the engine from the radiator based on temperature might have gone out.

Happened one time to a car I used to have.

 

Agree with thermostat replacement. Would also replace radiator cap if you have not done so in the last couple of years. Two inexpensive things you can do yourself. Also, make sure your engine coolant is the correct mix - Toyota Pink is premixed so if you are adding that you are good. Then see how it goes regarding radiator or water pump replacement.

 

I would do radiator as well. You might have a restriction inside, like debris or residue over the years that has gone stuck and impossible to see.

 

I'm definitely leaning this way, I might just do the water pump while i'm at it

 

Before you just throw money at a radiator, get an infrared thermometer and start spot checking. If you have an obstruction, you should have cold spots. Thermostat stuck open sounds about right for the symptoms assuming the fan is good.

If you're paying someone to do this, just say overheating and the fan clutch is new. Don't ask for parts, it's not their responsibility to make sure something is defective before replacing it.

 

At the end of the day, the thermostat falling to pieces was the likely culprit



However, while I was at it, I had my shop put in a new radiator as well as rebuild the fan clutch by changing the oil they come with and putting in some thicker stuff along with optimizing the temp the clutch will start to move air.

They do this with 80 Series a lot and it really helps

Everything is running perfect now. I went wheeling last weekend and spent the whole day with teh AC on. Temp was always exactly where it was supposed to be

 

Didn't know you could mod the fan clutch. Will have to look into this as I replaced everything in my cooling system including multiple caps and this is my second fan clutch in 1.5 yrs.

 

I see you're in the Phoenix area. I can send you a phone number of a shop that will do it if you don't want to tackle it yourself

 

Yes - would love to know of a shop that can do this in the Phx area.

 

FYUI My engine idles at about 650 rpm. Turning the AC on does not increase idle speed. Pretty sure the fan is not moving enough air at an idle. Going to look into that, but modding the fan clutch does sound like a good idea. Would like to know the shop that can do that.

 

Check your PMs, I sent you a phone number last week

 

Got it - Thanks will pursue. Appreciate your help!