[jesse]

hello there guys, i have a 2001 c5 w/ 69000 miles. lately its been running hot, well after its been on traveling for about half hour. itll go from 220 to about 250 on the highway ?, usually it ran about 200. i already did all of the tests, checked por plastic bags or misc. stuff stuck on radiator and its clean. i even cleaned out the dirt. any idea as to what can i do. do u think changing coolant/ changing thermostat will work. the fans do turn on when i turn on a/c. any ideas plz. sorry its long. dont want to spend any money i dont have to. thanks in advance

 

[vettekid00]

Do both the fans turn on?

 

[racingvette]

Fans are programmed to run only under 35 MPH unless the A/C is on

Could be a stuck tstat not fully opening
Maybe too much antifreeze to water ratio as it does not transmits heat out as well as water.

Make sure no small head gasket leak which would up the water temp
Maybe belt is slipping or a water pump issue.

The 2 fans run at low or higher speed, check they do at long idles.

 

[jesse]

Do both the fans turn on?

yes they do vettekid, thats why im puzzled. im gonna change the thermostat as it is something inexpensive. ill go that route first. thanks for the reply , if you run into something new, let me know, thanks

 

[jesse]

Fans are programmed to run only under 35 MPH unless the A/C is on

Could be a stuck tstat not fully opening
Maybe too much antifreeze to water ratio as it does not transmits heat out as well as water.

Make sure no small head gasket leak which would up the water temp
Maybe belt is slipping or a water pump issue.

The 2 fans run at low or higher speed, check they do at long idles.

thats what im gonna check racingvette, i hope thats what it is. are they suppose to run low or high at long idles. and yes both fans work. antifreeze, thats something that i checked and noticed, the antifreeze resovoir was filled to the top, when i got home. at that time it was at 245 degrees. it might have more antifreeze than water. maybe i do need to flush it. thanks for the reply, if something new comes up, let me know.

 

[JBsZ0666]

This is what worked for me...as I had a similiar issue with my 2001 c5...

After personally trying to clean the radiator with a water hose and by hand..... I still had overheating...

Guess what it took...It took a dealership tech c4c5 specialist with a special tool he had to spray compressed air from behind the radiator with the car up on the lift to get all the crap that was wedged in the radiator fins...(that the hosed water following various forum directions didn't get)

That was my experience so consider it an option that might be one possible scenerio...

www.corvettemechanic.com

 

[jesse]

This is what worked for me...as I had a similiar issue with my 2001 c5...

After personally trying to clean the radiator with a water hose and by hand..... I still had overheating...

Guess what it took...It took a dealership tech c4c5 specialist with a special tool he had to spray compressed air from behind the radiator with the car up on the lift to get all the crap that was wedged in the radiator fins...(that the hosed water following various forum directions didn't get)

That was my experience so consider it an option that might be one possible scenerio...

www.corvettemechanic.com

do you know the name of the special tool jb , was it an adaptor that you can utilize with an air comp hose. i need to try that cuz i havent cleaned it from the back. just the front and condenser. i hope its something like that. i know theres no trash in front or back. tom im gonna check that out. i read ur post from awhile back, do u remember if u replaced thermostat with reg. oem. thanks

 

[JBsZ0666]

I don't know the name of the tool used but I can suggest asking c4c5 specialist over at www.corvettemechanic.com

He's a world class GM tech and a good guy to share information.

check out the site and create a post.

HTH

JB

 

[T.M.]

Let the car just idle til comes up to temp. Make sure the fans are coming on at the proper temp settings, so when your in traffic, you know there actually coming on. With NO AC running the fans come on at low speed when the coolant reaches 226 degrees. Then both go to high speed at 235 degrees.
Your local auto parts store sells a product you spray into your radiator and a/c condenser fins. When this product foams up, it flushes all the packed dirt a bugs from the cooling fins, then flush with low spray water, can actually see thru the radiator and condenser after cleaning. Im sure you already did this, but the coolant level is normal? Yoy dont have the common leaking hose to the expansion tank, which could also introduce air to the system.

 

[JBsZ0666]

I'm not a mechanic and I don't pretend to be one on TV....and I'm going off memory..

The air conditioner radiator is first and then behind that is the cars radiator.

there is a small tool my technician used to properly get between the radiator if I remember correctly to blow the air out ...

I'm not a tech....so my best advice is to ask over at that other site I suggested.

Good luck.

 

[T.M.]

Let the car just idle til comes up to temp. Make sure the fans are coming on at the proper temp settings, so when your in traffic, you know there actually coming on. With NO AC running the fans come on at low speed when the coolant reaches 226 degrees. Then both go to high speed at 235 degrees.
Your local auto parts store sells a product you spray into your radiator and a/c condenser fins. When this product foams up, it flushes all the packed dirt a bugs from the cooling fins, then flush with low spray water, can actually see thru the radiator and condenser after cleaning. Im sure you already did this, but the coolant level is normal? Yoy dont have the common leaking hose to the expansion tank, which could also introduce air to the system.

I thought my radiator and condenser were pretty clean, after spraying the cleaning product into the fins, when it foamed up, tons of crap poured onto the ground. I was like, " damn". Hoses it all down, cherry!

Industrial air conditioning techs, like Trane, Fujitsu, etc also use these products on large air conditioning units. Should only take a few minutes to disassemble the fan shroud.

I you have an air compressor in your garage, you can make a fitting to fit the hose, copper tubing, like Jb is refering too, then bend a 90* tip on it, but you should still spray the fin cleaning stuff in there, the air alone wont clean it as well as the cleaning product used for this purpose.

 

[oilguy]

Dirt in your Grill

When I put my CAI on my vette I cleaned the fins out of the rad I first air hosed off the rad and then started spring the air straight into the fins and that was when all the small sand started coming out I bet I got two LBS of sand out .So my point is clean well with air hose in every fin put a tstat in it stock is OK but if you have a tune put a 160 in it flush it and fill with dexcool do not use green antifreeze Dexcool has better BTU transfer and is all in all better for your car also you did not say if your scoop is in good condition and spring are OK if it is failing it will do this also.

 

[chadmac99c5]

I'm pretty sure you can buy that stuff at Lowes I bought some for my house a/c worked great on the fins on home unit.

 

[jesse]

Hello guys, my problem was the water pump and thermostat. when they took of the thermostat, it came out all broken. the advice i can give anyone from my experience is to look at the bottom of the water pump and if u see a bit of leak or wetness thats your problem. i couldnt see the wetness until i was shown exactly where it was. and the thermo, well thats a first to start with. ofcourse all this with the cleaning of the radiator, bags, twigs, dirt, leaves first and make your way down. thank you all .