[Breethroz]

Man I havent been on here in a long time. Its good to be back.

Finally I am able to get in some wrenching time. I have not had the chance to work on my truck in a long time and the parts just keep adding up in my garage. My plan is to start working on the truck tonight and see how much I can get done.

I plan on installing new headers and exhaust system, a new thermostat, tie-rods, and change out my front rotors, brake pads etc.

My question is about the thermostat. According to the FSM I am supposed to drain out all the antifreeze. Is it necessary to drain out all the fluid? For some reason that seems a bit drastic to me. I can see the need to drain out a bit, but all?????? Can anyone shed some light on this for me? I have never had to replace my thermostat before.

FYI reason why I dont want to drain all the fluid out is because all the fluid in there is less than 2-3 monts old.

 

[TNRabbit]

I've always just opened it up drained most (to get below the point of the thermostat) into a 5 gallon bucket, then strained & re-added when I was finished.

 

[PKile]

There's a little nipple on the radiator drain valve, I put a 6-inch piece of plastic tubing over it, that helps direct the flow so it doesn't splash all over the undertray. If it's fresh coolant, just drain it into a clean pan and pour it back into the radiator when you are done. No need to drain the block, by draining the radiator you will get the level below the stat.

FYI, if you've never done it before, the thermostat uses a grooved O-ring on its edge to seal the water outlet to the manifold, not a regular flat gasket. A lot of aftermarket places seem to want to sell you a regular gasket, and they don't work. I guess they think everything goes together like a Chevy smallblock.

Torque on the water outlet bolts is 19 Nm or 14 foot pounds.

Cheers,
Paul

 

[Breethroz]

Ok I know this will sound crazy but how in the hell does changing a thermostat effect the idle???? Changed my thermostat with no issues, only took about ten minutes. Now my idle went from about 1000 rpm to about 500 rpm. Truck drives just fine. The idle is just off. Now I can certainly adjust it but I can't think how the thermostat could effect the idle.

 

[fourwd1]

One possibility, You could have an air pocket in the cooling system that is preventing the EFI temp sensor from getting proper coolant flow, so it doesn't read temp correctly.

 

[Breethroz]

Hell if I know, I just took 10 seconds to adjust the idle and it runs perfectly now. I just thought that was very weird.