I have a close family member with a 2009 GMC Yukon 5.3l 4x4. The vehicle has 178,000 miles. The heater hose came loose and the coolant drained out. She kept driving it until the vehicle shut off(she didn't know any better). The engine is for sure blown. I'm thinking about buying it for what the junkyard will give her($2400). She has always done all the maintenance and the vehicle is in really good condition. I had the transmission fluid checked and the fluid was a little dark but not milky at all. I received a quote to put a reman engine in with a 2 year warranty for $4000.

Is there still a chance the transmission is also bad from overheating the engine?

What other components would likely to have been ruined from overheating?

What else should I have checked before I put a new engine in?

What else should I replace If I put a new engine in?

I really don't want this to be a money pit so any advice is appreciated.

 

When you so say “shut off” was it the computer that shut down the engine? Is the engine seized?

S.D.

 

I think I would pull the heads on the original engine to see how bad it is, but if the engine is seized and you put in the reman engine I would do the following:
- flush the heater core
- new water pump and hoses
- new torque converter
- new fuel injectors
- I’m assuming the engine will already have a new timing chain
- new PCV valve
- new fuel filter
- would be a good time to replace any weeping transmission and oilcooler lines as well as leaky power steering lines.
- might be a good time to replace the hydraulic assist master cylinder assembly.
- check the front suspension and replace anything that is worn.
- once the engine is changed out all the fluids: diffs, transfer case, brake fluid, power steering fluid.

Good luck

SD

 

The Yukon was run overheated until it finally shut off. The shop it's at right now said the cylinder walls were warped. I am going to need a new motor. I am not sure if I will need a new transmission. Or how to completely tell what else was damaged including the transmission or any other parts.

 

Although the high temp in the radiator would have heated up the transmission I really doubt it did any damage. The reason I say that is the coolant was blown out of the rad, so there was very little fluid to cause a heat transfer into the transmission fluid.

You can have the transmission filter changed and get the transmission flushed. I would take that chance. If it is damaged, to be honest, with 178,000 miles it was probably coming due for a rebuild anyway. “ Free advice is worth just that” Good luck!

SD