ok so i have done everything i can think of besides replacing my brand new water pump.

i have bled the system 8 million times and no air bubbles or spirts of any kind, replaced the thermo with 2 new 160's still didnt help.

so i go to start the car she starts up warms up and stays at 170 -180 but as soon as i start to drive it like down the block it starts to get hot.

will hit 210 - 220 in about 5 minutes and then if i keep drivin in it will hit 250- needle burried in about ten minutes i would guess but it got to 250 and i shut it off and will not let it get any hotter than 220 or so.

but i just dont know what to do, the water pump is brand new and it was on the car for 50 miles before the new cam and ran 170 on a hot day with me gettin on it every now and then.

i also have the fans to come on right as soon as the key is turned and still gets hot.

it has a new radiator from griffin and i even had the system flushed and refilled at gm, got the car back they said she is good to go and sure enough over heated on my way home. and taking it to gm was like going against my religion as a hot rodder but i was just stumped.

replaced all hoses even heater hoses, checked the heads to make sure nothing was left in there when i was porting them. the radiator is full and the catch can is at its peak level so i am clueless on what im missing.

any help is very much appreciated!!!!!

 

The guage could possibly be off. Im just throwing that out there

 

Is your air dam installed?

 

Took the words out my mouth

 

I run mine without the air dam all the time, and don't get that hot... I'd lean towards thinking you've still got some air in your system. I know I've struggled a lot with getting air out of my coolant a few times.

Try this out... with the car idling in your driveway, monitor the temps. If it starts to shoot up, open up the air bleeder screw in your upper rad hose. This has worked for me many times... I'll open up the screw, and the temps will instantly drop a TON. Try it out.

I actually keep a small wrench in the car for this purpose. For some reason, on random occasion, my temps will shoot up. I pull over, open up the bleeder, and problem solved.

 

You're asking for trouble. The air dam is an integral component of your cooling system. You get no air flow across the radiator without it. I'd bet what you're venting is steam bubbles, not air.

 

Are your fans working and what temp on/off do you have programmed in the pcm?

 

Check the front of your radiator for debris or obstruction?

Knew a guy who sucked up two plastic bags going down the road and they plastered themselves to the front of the radiator. Not good.

The chin draft/front air dam is important. If you don't have one, get one.

Bleed the system with car running until a solid stream of coolant is coming out of both fittings.

 

well i dont have the air dam on it right now so maybe that would explain that it only gets hot when i drive it, hmmmm.

as far as bleeding goes i have bled it with the car running opened up the bleeder on the rad hose and rev it up to about 2000 or so and hold it for a few seconds let it come down and keep doin that till its a solid stream. then the same thing on the heater hose bleeder.

@ dadic 78 ill try that today and see if the temps drop, but if so then what does that mean?? still air in the system? or too much coolant??

 

You just gave yourself the answer. Get the air dam back on and all will be well.

 

i ran a lt1 with out an air dam for a short while and it would idle fine due to the fans being able to move enough air. when you start driving the air that the fans are trying to suck through the radiator is just going directly under the car instead of being directed up into the radiator. i would guess that it is creating a sort of vacuum effect. put your air dam back on and your problem will most likely go away

 

Air dam! Because of aforementioned reasons. I took mine off before and had the same issues you did, just thought it was a useless piece of plastic at first, boy was I wrong.

 

ha ha wow one plastic piece can cause total motor failure!!! i guess i will bolt the thing back on and take her for a spin!! if it fixes the problem i will try to send each of you a 6 back of beer lmfao

thanks guys

 

I like Pacifico.

 

thermostat sticking.

 

It means you've still got some air in your system. If I'm right, I'll take a 6'er of PBR, that's Pabst Blue Ribbon, baby! You can ship it right to my house!

 

Brucer i have gone threw 4 thermos all new to see if it would change and nothing, im gunna slap the dam back on tomorrow and see what happens!!!

 

Try replacing the air dam. If that doesn't work think about this. I have a 96 Z and it overheated at times. I did everything you did... still overheated. Then I watched to see at what time or times the fans kicked on. For some reason they would kick on at different times at different temps. Aside from that issue I hade to get a tune but mentioned that my car was getting hot and asked them to check what the computer was set to and modify if needed. I installed the tune and it hasn't over heated since. Just somethin to think about.....

 

very true but i have the fans on as soon as i turn the key and they never shut off they are hard wired in so thats not the problem.

 

sounds like the same problem i was having a month ago!
this needs patiences.
change the 2 coolant temp sensor mines were not sending the right signals to the fans!
change the thermostat!
also change the coolant sensor on the radiator!
flush radiator
check for rotten hoeses and change them.
i change all these thing and now it dont overheat but the gauges doesnt read the right temp, when the scanner reads 225 and the gauge is almost touching the red. be patient!
it took me like 2 weeks to get the problem but all these techs in this website know what they talking about they are a great help!