So I put a new cam in my car, and its been running for the last week and a half. I made sure to bleed the coolant, and then re-bleed it a day or 2 later and it was fine. So fast forward to last night, I drove 300 miles on the highway to meet up with my tuner, and it ran at 170 degrees the whole time. Then I got off the highway and 5 minutes later my check guages light came on and my coolant guage was in the red. So I pulled over and popped the hook and I could feel and hear my coolant boiling, so I know its not a faulty gauge. So then I let it cool off for a couple minutes with the fans on, then I started it back up and it ran fine, it cooled back down to normal and didn't have any misses or anything. What would cause the car to suddenly overheat like that? I also have a becool radiator so it ALWAYS runs cold as hell. I also have a GM waterpump with 20k on it tops. Theres no leaks in any hoses or anything. I have no idea why it would just suddenly overheat.

 

My car did this after a long drive at over 70 mph. I was driving for 100+ miles on the freeway and then exited and stopped the car. The gauge would go up to a higher than usual level and then cool soon after i drove it some more. You had a lot higher reading than me but i could also hear the coolant boiling in the reserve. I would watch it closely and not drive it far until your sure it won't happen again. I figured it was from the new thermostat that just needed to be worked in a bit. Right after the replacement i watched the temp gauge for the first few miles and it would go way up and then all of a sudden drop and never overheat again.

 

I know it's simple, but did you check the coolant level? You may have just hit an air pocket or something. Did you have your fans off on the highway and forgot to turn them on when you exited?

 

Fans come on automatically, and the coolant level was fine when I left.

 

Sounds like a thermostat issue.

Bret

 

if its not leaking and the coolant dissappears you have a blown heads gasket, whitish smoke that smells like cotton candy will come out of the tailpipes in the most extreme cases.

are you saying it was fine when you left as in after it overheated? or before you left and then it overheated?

 

if its not dissapearing than its just overheating out of no where i vote ^^^ what bret said.

they are 6 bucks

 

Would a thermostat just close all of the sudden? It's not like I started the car and it overheated right away, it was after a 4 hour drive never shutting the car off then it overheated. And the coolant in the radiator was BOILING, I could feel it shaking pretty violently when I popped the hood.


My friend said he thought he saw white smoke come out of my exhaust when I was at 1/4 pedal but he wasn't sure, but coolant is definatly dissapearing. I opened the radiator cap and started the car and bubbles kept coming up even after I bled the coolant again. And like I said coolant is definatly disappering. Whats the easiest way to check for a blown head gasket?

 

do you have coolant in the oil? oil in the coolant? how much coolant did you put in it total? I ask b/c you could have had some air pockets in it

also did you replace the t-stat?

I don't know why you would blow a gasket all the sudden, unless you were running the crap out of it

 

milky oil, and sweet smell coming from the exhaust. dissappearing coolant is a pretty big sign in itself.

sea foam will eat gaskets, also you need to get on top of this problem fast or are gonna need to replace your bearings