Engine Flush and Radiator Flush, Transmision

[ryan255]

I have an Envoy with 4.2L with 24K,

 

do I need to Flush the engine or radiator?

 

In how many miles?,

 

 

And in how miles I change the transmision oil?

[TonyMazz]

Aren't those issues covered in the Owners Manual maintenance schedule ?

 

If you are running DexCool (from the factory) you should have to flush for 100K.

 

If you are not towing anything, you should not have to do anything with the tranny until about 50K