Coolant system problem?

Here's the story:

Some how my radiator cap came loose on my way home from work yesterday afternoon. I started smelling coolant just before my driveway. It didn't appear to have lost too much and wasn't hot, but still struck me as odd.

So on my way to work this morning, with outside temp being around 35 degrees, I noticed how quickly my truck warmed up (red flag #1). About 10 miles down the road the engine temp started to climb (red flag #2). A few seconds later the temp dropped back down to normal...? After a couple of these rise and drops in temp, I pulled over popped the hood....coolant low. I expected that. What I can't figure out is the fluctuation in the temp. My heater was working and the temp never made to the red even after I turned around went back home and switched vehicles.

I'm thinking thermostat, but I want some other input.

Sorry for the long winded explanation and thanks in advance for your help.

 

Maybe air pockets in the cooling system? But its still odd. Not sure?

 

I read about "burping" the system when I did a search. How is this done?

 

I would say the same it sounds like air pockets... I bought a Prestone flush and fill kit and just replaced coolant too (needed it)

 

The air pockets would make sense. About a month ago I got into some real deep mud soup while offroading......to make a long story short, my radiator clogged with mud(the fins) and a bunch of drunken rednecks were screwing with the radiator trying to assess the problem.

 

yeah autozone or advance auto carry the flush and fill kit...they are like $8

 

Since you mentioned that your cap was loose....

I'd start off by getting a new radiator cap and top off the radiator and overflow tank and see what happens.

The radiator cap is more than just a cap - it helps keep the system pressurized which allows the water to heat up at higher temps before boiling.

Check this out
http://www.musclecarclub.com/library/tech/cooling.shtml

 

Thanks for that link, Janster. Very informative. I might have to give a new cap a try.

 

Update: I replaced the radiator cap and brought the coolant level back up to where it should be. Problem is, now my heat isn't working. Just blowing cold air.

 

alright, finally got heat, but it sure took a long time.

 

sounds like a thermostat problem, but yea on Toyota's you have to burp the system. Sometimes if you change the fluid and don't burp it you will get a red indicator light come on the dashboard.
What I do to burp the system is fill it up and let it run, sometimes it takes a while, then just top it off.

 

It's all back to normal now. In hindsight, I think the thermostat was just sticking, and now it isn't. If I have a problem again, I'll just go straight for the thermostat. Thanks for the tip, though.

 

thats what it sound like to me the thermostat is sticking you need to get it fixed the heAT WONT WORK STUCK OPEN OR IT Will over heat stuck closed i think