question about overheating

[newbie78]

I was letting my truck idle and the temp was going over 210 so i shut it off. I went to see if their was pressure in the radiator and slowly turned the cap and their was but I could open it. Some of the coolant splashed on me and it was cool so i stuck my finger in the radiator and the coolant was cool. How could that be if the temp gauge was going over 210? I took out the oil dipstick and that thing was scorching hot!

Just trying to figure out why my truck is getting hot fast. Within 10 minutes it will go up to 210+. I know the radiator is leaking but would that cause it to overheat if their is plenty of coolant in the system?

Is it because of air getting in? Just weird the coolant is cool at that temp. Maybe the coolant temp sensor is bad?

I was going to replace that today but I didn't because I wasn't sure if I had to drain any of the coolant out. Can I just unscrew it and nothing will come out because it's high up on the engine?

thanks

 

[MC153]

Sounds like a thermostat if your coolant is cool. Probably not letting the coolant in the motor.

 

[newbie78]

Sounds like a thermostat if your coolant is cool. Probably not letting the coolant in the motor.

I squeezed the upper hose it was tight. Most of the hose was hot closest to the engine but near the rad it was cool.

 

[_Dylan_]

take off the thermostat housing and remove the thermostat too see if it runs cool without it

sounds like its stuck closed.

 

[newbie78]

take off the thermostat housing and remove the thermostat too see if it runs cool without it

sounds like its stuck closed.

Ok. When I take the top hose off will a bunch of coolant come out? Trying to do this with minimal coolant loss.

---------- Post added at 11:01 PM ---------- Previous post was at 10:54 PM ----------

I'm going to put a new stat in anyway. Not gonna run it without one because I read it could cause it to run in open loop and cause more issues.

 

[SunlitComet]

Agreed, it sounds as if your t-stat is frozen shut. The coolant would spill out if not drained some to replace that sensor. You would need to drain it some anyways to do the t-stat so if the coolant is dirty and old flushing it out while you do the t-stat job is a good idea.