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RX running too hot

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This disgusting heat is pretty bad for my car. It keeps heating up when driving in town. We've been holding steady in the mid 90's, bright sunlight, and high humidity. The fact that the car is black doesn't help.

 

When driving in town the temp gauge just keeps creeping upward, even if I don't have the A/C on. I've never let it hit the red zone, but it gets well into the top 1/4 of the gauge almost every time I take the car through town. Thanks to the people in this town driving like a flock of sheep, I rarely break 25-30mph anywhere in town (even though we have 35 and 45 zones all over the place). The temp gauge does NOT come down either- matter of fact, if I sit and idle anywhere on pavement, it gets even hotter. While driving it just won't drop unless I coast down hills in neutral.

 

But, I know there's nothing seriously wrong with the engine or cooling system- when doing over 35 or so it stays around the middle of the gauge, and on the interstate, I can do 70 with the A/C cranked and the temp needle stays at about 1/3 of the way up the gauge!

 

The car has a brand new CCR engine with a brand new water pump and brand new thermostat. The radiator is in great shape and full of a 50/50 coolant/water mix.

 

What the heck else can I do? This high temp has me really concerned.

  • Author

Yes, both fans, and they both work. Electric fan cycles just like it should- which means it clicks on shortly after leaving the house and stays on until I shut the car off, in this kind of heat.

  • Author

Radiator looks great. It's not new, but is one of the best looking ones I've seen.

throw more water in the coolant, or try to find one of those coolant additives (liek redline water wetter, mougl inga-gel(sp?) is it a two row or a one row radiator?

What is it with you and cars overheating? :)

 

Seriously just because the radiator looks good doesn't mean it's not clogged up. After you drive check for cold spots on it. ONly half of mine is working right now and that makes for bad cooling.

 

You do a 185 t stat too :) Seemed to help a bit.

How old is the coolant? Are there any trapped air bubbles in it?

just because the radiator looks good doesn't mean it's not clogged up. After you drive check for cold spots on it. ONly half of mine is working right now and that makes for bad cooling.

 

I concur. Sounds like a classic inefficient radiator.

Could be a bad radiator, but they normally have trouble with higher load (the faster you go the hotter it gets). Try running the heat on full (miserable I know), if its the rad that should help.

 

You say the electric fan is working so that kills my first guess. Can you hear the clutch fan pulling? I always know when mine is on, it whirrs like a turbine.

 

This sounds more like a coolant flow issue, water pump falure is unlikely (but posable), I'd check out the thermostat, just cause its newer don't mean it's good. Is it an OEM or aftermarket thermostat? I personaly haven't had an issue with the generic type in a subie, but I've had them bad right out of the box for other cars. And I have noticed that the OEM Subaru thermostat has a larger opening (disk diameter). I'd pull the thermostat and run it like that for a day or to and see how it does.

 

Gary

doesnt coolant boil at a higher temp. i know i had just water in my car and it over heated a lot but as soon as i put coolant in it it didnt heat up so bad at all. so maybe you need to go with strait coolant. im not a subaru guru but its just from my experience.

  • Author

Never had any boiling. The pressurization of the cooling system raises the boiling point of the water. If your coolant is boiling and the temp gauge isn't in the red, it means you've got a pressure loss somewhere.

Never had any boiling. The pressurization of the cooling system raises the boiling point of the water. If your coolant is boiling and the temp gauge isn't in the red, it means you've got a pressure loss somewhere.

 

 

That would be my guess.. The symptoms don't really sound like a bad radiator.. My bad soob rads have always given me trouble at highway speeds, not cruising around town so much..

 

First thing that realy comes to mind is a bad Tstat or radiator cap.

First thing that realy comes to mind is a bad Tstat or radiator cap.

 

Good point. When I put a new rad cap on my car stopped over heating.

just went through this on my wagon.. lol symptoms exactly the same.. if it got up to 3/4 i could shut the car off and just leave the fan run and it still took over an hour to get it to cool off.. the radiator was holding the heat and not lettin it go..

 

i swapped out the radiator with a good one and bam, my car now runs at 1/4 on the gauge, electric fan never comes on unless i sit at a light, then its on for

1 min 14 sec. and shuts off..

 

ohh, i even towed another soobie 17 miles in 95 degree weather and never got my temp gauge over half... and that was towing up/down hills about 30-40 mph..

 

 

i'd say change the radiator and flush out the heater core while your at it, a partially plugged heater core will cause temp issues too..

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