please help i have a 95 seville thats overheating and i've replaced everything i can think of. the thirmostat i've replaced twice and checked them in boiling water. radiator is less than a year old brand new. water pump looks good, i pulled of the thirmostat houseing and could see the in side of the pump the fins look good the belts good. it works good for a while gets to about 208 and stays. after i jump on the highway or let it idle for a long period of time it will slowly climb to about 255 and stop usually and wont go down till i turn it off. i've been filling it with water. i started out using coolent but that got expensive quick. i'm at a dead end please i need ideas to try i'm completely out

 

Any signs of oil in the coolant? Any coolant leaks from engine?

 

No there is no oil in the anti-freeze or af in the oil. it's not smokeing, and theres no bubbles under the radiator cap. so i don't think it's a head gasket. also i can't find anyleaks i've had a small leak for years. well actually i mean i've had to put fluid in it regularly but i never could find a leak anywhere letting it run. i don't get puddles i've sat under it while it ran. so if there is one i can't find it :-(

 

Ok then, can you confirm that your electric cooling fans are functioning properly?

 

I agree with the Katz, but it wouldn't hurt to do a quick pressure test since you run low regularly.

 

A good radiator shop can verify combustion gases in the cooling system. Having to add water is a sign of a leak, either internally or externally.

 

sometimes we assume too much .. have you read this?

https://www.cadillacforum.com/m_7193/tm.htm



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the fans always work when it's idealing i can't tell driving. but they always come on around the same temp ... i beleave around 195ish both fans do. usually the first time it warms up it does automaticly over heat.(idealing or driving) it'll will climb to like 208 then drop to 190ish ... then it usuall climbs to 225 and sit s for a while or drops a little before slowly climbing to 245 and higher. but as soon as it hits the 240 mark and higher it usually rises really slowly (again i'm getting the same results driving and idleing in my driveway)

 

they are out there by the thousands .. and yet, no one listens to us ?
change the COOLANT, YESTERDAY !



http://losangeles.craigslist.org/lgb/car/736220572.html

 

You know I am going to be optimistic and lean toward the water pump. Where the pump is situated allows it to leak and run down on hot engine pieces and evaportate without every hitting the ground. What do you have to lose by changing the water pump ? I mean you have a 13 year old car anyway so it can be viewed as preventitive maintenance. This way you will know for sure you have a good rad, thermostat and pump. If it still overheats then you have a more serious issue to repair. If it is a head gasketthat doesn't mean the car is junk either, I just replaced the head gaskets in my 99 Suburban ( DEXCOOL II as well) and no one was freaking out about that, 9 year old truck so what's the big deal, runs like new, in fact it never ran bad even when leaking.