Flush & Refill - 2002 GMC Envoy

[[email protected]]

My 2002 Envoy (4.2L I-6) has 140,000 miles on it. Ive owned it since 60,000 miles, circa 2004.

The water pump is *just about* to give up the ghost, with a whole bunch of play in the water pump shaft, but not leaking yet. I plan on replacing it in the next week or so.

I replaced the t-stat around 100k, and partially drained the cooling system and refilled with 50/50 Dex-cool Prestone.

I would really like to drain out ALL the coolant this time, fill it up with a flushing product, drain that, THEN replace the water pump and refill with NEW dex-cool.

What is a good recommended "flush" product, and what coolant is recommended here on the forum?

 

[oldmaninsc]

Originally Posted By: [email protected]
My 2002 Envoy (4.2L I-6) has 140,000 miles on it. Ive owned it since 60,000 miles, circa 2004.

The water pump is *just about* to give up the ghost, with a whole bunch of play in the water pump shaft, but not leaking yet. I plan on replacing it in the next week or so.

I replaced the t-stat around 100k, and partially drained the cooling system and refilled with 50/50 Dex-cool Prestone.

I would really like to drain out ALL the coolant this time, fill it up with a flushing product, drain that, THEN replace the water pump and refill with NEW dex-cool.

What is a good recommended "flush" product, and what coolant is recommended here on the forum?


I rarely ever use a "flush" product. I really don't think it's necessary. Flushing with water usually works well.
I replaced the thermostat in my 05 Trailblazer EXT around the 4.5 year mark with about 50,000 miles on it. The inside of the engine was very clean. I refilled with Prestone Dex Cool.