Hey! Professional mechanics

[Caster]

I got a question.

I have a 2007 Toyota FJ, 4.0L

I just rolled 70,000 miles.  No, I don't drive much, I work at home :cool:

 

It's time, so I replaced the serpentine belt and did an oil change.  Easy belt change once I found a youtube video.

 

Then I break out the water hose and some radiator flush.  7 years is long enough on anyone's coolant.  Drain it, fill it, run it.  All pretty easy to do.  

Now here's what I do NOT understand.  I ran the engine for 15 minutes until the temp hand came up about 1/4 of the way with the heater on high.  Then I ran it for 15 more minutes and was gonna drain it.  Carefully I opened the petcock and it's cold as ice.  Close it back, start it up and drove about 30 miles with a piece of cardboard in front of the radiator.  Get home, the dam bottom radiator hose is still cold and when I drain it, it ain't even WARM! The top hose was just warm enough that you won't hold on to it for more than 5 seconds.  Certainly not HOT though. WTF?  The last little bit of water was barely warm.  NO radiator works THAT good.  The old small block chevys I'm used to would have been hot enough to send you to the emergency room after almost an hour of running.  And when I drove it, I wasn't exactly driving Mizz Daisy to tha Piggly Wiggly.  I stuck my foot in it pretty good.

The temp gauge never got past half way and the heater was [as it always is on this thing!!!] hot as hell.

 

I drained it and rinsed it with the hose till it was clean and filled it back up with 50/50 Universal Prestone.  

 

I guess I shouldn't complain I just don't get it.  

[TGO David]

Have you asked over on FJForums?  I used to be a very active member there when my wife and I both had FJs.

[Fourtyfive]

Sounds like a stuck thermostat , but the temp gauge should have really climbed. Edited December 22, 2014 by Fourtyfive

[hipower]

Sounds like a stuck thermostat , but the temp gauge should have really climbed.

 

But if the thermostat was stuck, would you have gotten heat from the system in thru the heater vents?

[Fourtyfive]

Not familiar with his system , maybe.

[Fourtyfive]

You didn't miss the water pump pulley when you put the new belt on did you ? :)

[peejman]

You didn't miss the water pump pulley when you put the new belt on did you ? :)

And if you got it on there, you're certain it's turning the correct direction?

[DWARREN123]

Also many engines have a petcock to remove air when filling. It must be open until fluid comes out.

Edited December 22, 2014 by DWARREN123

[Caster]

And if you got it on there, you're certain it's turning the correct direction?

That's not possible. The way the idlers and belt route is laid out, you can't really get it backwards. It's either on there or it ain't.

[Dustbuster]

Might be full of air w the thermostat stuck open. Fwiw thermostats typically default to open when they go bad. Temp gauge can give a false read if there's air in the system. Edited December 22, 2014 by Dustbuster

[Tobashadow]

Air in the system, park it up hill with the cap loose for a few hours.