Well for the past few days I have been car-less. Here is the situation.
First of all I was driving down the highway like normal (about 55-60mph). I happened to glance at my temp guage and noticed that it was near the H. I immediatly pulled over and checked under the hood. I couldn't see anything wrong. I drove it home fine after a while of letting it cool down.
The next day I troubleshot the car and found a cracked radiator. I replaced the radiator. Test drove it... worked ok for a little while, but out of nowhere it overheats. If i let it cool for a little I can drive it again for a few more miles. I got home checked my hoses and realized that my bottom radiator hose was cold. My first thought is... my thermostat.
Next day I bought a new 'duralast' thermostat with a gasket already attached to it and some new drive belts. I replaced the thermostat and the belts at the same time. Drove it... good for a long while... but then overheated. I took a look under the hood... It was boiling in the coolant reservoir. My thoughts... faulty radiator cap. So i bought a new cap. Drove a little hard... good... checked the bottom hose... at least it was getting warm.... not hot... but warm.
Next day.... drove for a long time... but then the car started overheating. I looked under the hood... bottom radiator hose was cold again! I saw some coolant leaking from the seal of the thermostat housing... tightened it and drove home...
And this is where i stand now... i dont know what it is. I almost replaced the whole cooling system besides the water pump. Water pump isnt leaking... so I dont think thats the problem. Someone told me to do a compression test to see if I have a blown headgasket. Is that the problem? could it be that I just need to put some RTV silicone gasket along with the thermostat gasket to seal it better? I dont know... does anyone have input?
Oh... by the way when the car overheats... occasionally i can drive and it will go back to operating temp, but thats if i drive slow. if i drive about 60 it will go back up. Anyone can you help?

 

take off ur thermostat cap and run the car til normal operating temp., then watch the rad. fluis to c if it being circulated throughout the radiator. This is a way to tes if ur water pump is working or not, now if the fluid isnt flowing when ur thermostat should open up, then ur water pump probably needs to be raplaced. If the fluid is moving at a nice steady pace, then your headgasket needs to be replaced, sorry but thats gona be it. How many miles are on the car and what motor are u running?

 

Not the thermostat cap, no such thing. Try the radiator cap. Start the car. Let the car natually come up to operating tempature. Watch to see if your radiator coolant level drops, bubbles, swirls. If none of that happens, pull off your radiator hoses. Check for obstructions.

If no obstructions, take out the termostat completely. Repeat above. If it still doesn't move the coolant around, you have a blockage in your block, or your waterpump has stopped working and you need to replace it.

If the coolant moves around correctly like it should w/o the thermostat, get another one. Take it in your house and put it in a pot of water and bring the water to a boil to ensure the thermostat is operating properly. If it is, install and try again.

IF the problem STILL persists, take the car to a mechanic to have them throughly check it out.

 

betting on the water pump too

 

thats what i meant...also are u having any type of smoking going on? and when ur car does overheat does the fluid in ur overfill tank bubble like air is being blown in? Lastly, is the car eating up the radiator fluid? Those are all signs of blown headgasket, which is very common in 240's.

 

Well my car has about 228,000 miles on the engine. Most of them are highway miles (trips to virginia). I'll try the radiator cap method and let the car run to op. temp. to see if there is anything wierd. To answer someones question... no it's not eating any coolant and the only smoke coming out of the exaust is some oil that is getting into the exhaust from the oil pan leak. There was some bubbling in the reservoir before i replaced the radiator cap, but nothing after. I'll try installing a new water pump after i run a compression test. Thanks for the help guys. Hopefully it works... anyone else have any ideas on what it is?

 

It could be that from so much over heating the cilinder walls are scratched and all the bearign that hold the crackshaft are worn and everytime you run the car the friction is so great that it makes the engine over heat. now this would only be worst case scenario, and would imply a total engine re-build. Technically a shot engine. But then again, this is a WORST case scenario.

 

and i dont think you would have oil smoke coming out of your exhaust from an oil pan leak...... unless you mean it is getting on the exhaust pipe and leaving a smoke trail......

 

lol.. sorry was a little tipsy when i wrote that... i ment to say it has an oil pan leak... and its smoking prolly from worn rings... LOL!!! but just found this old tread and thought i'd enlighten you with the solution to my problem...

it was a bad fan clutch....!!!! LOL!

 

*wheew* thank god you cleared that up for me! ive been losing sleep for the past year and a half

 

holy thread revival...and i didnt know fans had clutches..maybe ur tipsy again lol

perhaps the clutch fan??? lol

lol quit frontin durdan uve only been losing sleep for 5 months..unless uve been lurking for a year before that...u sneeky lil ninja!

 

Funny guys!