2006 3.4 randomly overheating

[afazaky]

Alright day or so before xmas my neighbor asked me to take a look at his torrent after it had over heated while left idling. He also claimed to have lost heat.

I noticed his coolant was low but we couldnt get it to over heat. He used it for work an said it happened again. This time loosing heat completely.

I replaced the thermostat an it seemed to make everything better for day or two.
Again it randomly overheated a day ago. I also noticed smoke at start up that smelled like coolant but it went away after warming up.
After every time it over heats he is low half gallon of antifreeze. It doesnt appear to be dripping below car so i can only imaginr it burning in engine or heater core leak.

I want to point to bad head gasket but oil looks fine. I did compession test an the front 3 gave me 120psi and i only tested 1 rear cylinder bc they are so fun to get to an i got 130+.
Finally the plugs from the front all have white build up n look extra worn compared to the rear one i pulled.

SHORT VERSION:
Car randomly overheats when left idling but goes back down on own after driving off an looses heat in cabin.
After over heating coolant level low half gallon.
Thermostat replaced
Oil isnt milkey
Compression good in rear lil low up front
Front cylinder plugs have white build up

Basically coolant dissapearing an car randomly overheats.

 

[melsg5]

have you pressure tested the cooling system? Could be a lower intake manifold gasket sucking in coolant.

 

[afazaky]

Is that like a leak down test? Send compressed air into spark plug hole an see if bubbles come out in the coolant reservoir?

 

[melsg5]

you attach a hand pump with a gauge to either the radiator cap or pressurized coolant expansion tank and check if the pressure drops and if there are any visible leaks especially around the intake gaskets.

______________________________

 

[afazaky]

Well for the record the heater core had gone bad an coolant was filling up in lower vents.
I replaced it however when putting everything back i didnt hook up the key fob coax antena wire. I can see the plug dangling down from the pillar but i cant find the godamn RCDLR box to plug it in.
Where the sucker located?

 

[Maxco]

I just replaced the lower intake manifold gasket on my wife's '06 Torrent. Kept losing heat and you could see where it was escaping on the gasket. Luckily her car never overheated.
Heat is great since then.