Engine Coolant Temp Problem - Please HELP!

Coolant Temp Problem - Please HELP!

For some reason just the other day I was driving around with the heat on and it all of a sudden started blowing cold. So I shut the heat off and after a couple minutes did it again and it was fine.

Today, I am driving my car to work and my coolant temp is acting sparatic. Going up and down, after I stop it goes up then I turn on the heat and it goes down, and quick! It's up I drive fast and it goes down... hrmm...

I'm thinking there might be a clog in my coolant lines somewhere. I dont have a leak or else it'd be smoking. My engine isn't overheating either becuase there's not smoke. I know this becuase I ran my car low one time on oil waay back and my temp was still low and it was smoking from the bay a bit.. It's not doing that.

I have 145,000 miles on my 97 1.6l 4afe... Coolant filled about 2 months ago...
I'm gonna get some seafoam stuff and see if that helps tomarrow... What do you guys think?

mmm...possibly this: 1. water pump malfunctioning, perhaps on the verge of leaking or failing 2. leaking radiator hoses? 3. radiator fan malfunctioning 4. THERMOSTAT failing! -thats prob what it is- could be also a prob with heater core...

Yeah I don't think it's the heater core becuase the wouldn't affect the temp of the engine... but the thermostat is most likely what I was thinking too...

sounds to me like the therostat...seafoam won't help the coolant at all, but i think you mean to say your going to use it in the intake system. i put it in my mom's 99 mazda 626...wow, you can't even hear the engine when it's on, all you hear are the belts