Coolant Missing, Running Hot, White Smoke, Burning Oil

[Brian Lamb]

Another update...

The mechanic told me he thinks it's just the radiator cap. And also the motor that is in the truck is not the original motor.

This sounds really weird to me. If it was not the original motor and the truck only has 158,000, why would it be smoking at start up? It sounds like valve seals to me.

Also, why would the spark plugs be so corroded?

 

[Rocket Man]

I'd find another mechanic.

 

[rockola1971]

How exactly does the mechanic know that the motor is not original to the vehicle? Did he check the "imaginary serial number"?

 

[Brian Lamb]

How exactly does the mechanic know that the motor is not original to the vehicle? Did he check the "imaginary serial number"?

That is what I was thinking. I am going to take it somewhere else Monday.

 

[Brian Lamb]

I went back to the mechanic today.

I asked him if he could do a pressure test to see if it was still losing it or not and he said doing a pressure test would not show if it is losing coolant or not.

I told him nothing adds up because the spark plugs are so corroded and I would definitely see two gallons of coolant if it were to be coming out of the radiator cap.

He told me he was not going to argue with me and that nothing is wrong with the truck.

So I got my keys and I took the Tahoe back.

 

[mattt]

Have you looked at the weep hole or "tell tale hole" on the bottom side of the water pump? If you're under the Tahoe and look in precisely the right spot, you can see the hole. That is often where they leak from when the water pump is giving up the ghost. Do you have a rotational squeak from the engine, mostly when cold? That could be water pump bearing. I'm at this exact point now with my 04 and have looked underneath and saw the orange trail of coolant, none of it ever has hit the ground.

 

[iamdub]

Are you sure it has "only" 158,000 miles? Gauge clusters are easy to swap. Also, the mechanic at the dealership from which you bought it is not going to be very inclined to perform relatively major work on something for free. There is certainly something wrong with the truck.

I figured you would've mentioned this already if you did, but do you regularly smell burnt coolant from the engine bay area after driving it?

 

[Brian Lamb]

I smell no coolant at all. And I see no coolant at all anywhere. I've looked. It's "disappearing".

 

[iamdub]

The only other "way out" is through the engine, and the only way it's getting into the engine is through a cracked head(s), head gasket(s) or cracked block. Have you compared all the plugs in their respective cylinders? It's hard to tell from the pic, but those deposits on the plug looked normal. Either they're actually worse than they appear or that plug was pulled from a non-affected cylinder. A plug could be fouled from a cylinder burning coolant. Have you checked the oil for traces of coolant or the coolant for traces of oil?

 

[mattt]

I smell no coolant at all. And I see no coolant at all anywhere. I've looked. It's "disappearing".

Did you lay eyes on the weep hole on the bottom of the water pump snout? It will be dry, due to engine heat, but if there is any discoloration on the aluminum water pump housing, there is your missing coolant, dried up.