Huge win for car owners! All TSBs to be made public. The Center for Auto Safety just made the NHTSA (US Government) make public the full text of all TSBs from now on. They are the same organization that has petitioned the NHTSA & filed lawsuits to protect car owners over exploding gas tanks & other major safety issues. Whenever you drive in your car, you are safer thanks in part to a lot of work over the years by this small but very effective consumer advocacy group.

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definitely annoying
Typical Repair Cost:
No data
Average Mileage:
83,885 miles
Total Complaints:
1 complaints

Most Common Solutions:

  1. replace coolant lines (1 reports)
2004 GMC Envoy AC / heater problems

AC / heater problem

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2004 GMC Envoy Owner Comments

problem #1

Dec 012010

Envoy EXT 4.2L V6

  • Automatic transmission
  • 83,885 miles


The engine coolant lines leading to the rear heating unit failed and anti-freeze dripped out. The solid aluminum lines cost over $1K for the part alone, then add labour on top. I opted for the cheap fix which was to crimp the lines off near the engine and for go rear heat ($300). My GMC dealer told me that the design was poor. Insufficient fluid movement contributed to sludge building up. I am not sure how that contributed to Al corrosion, but I accepted that they saw a higher number of these problems showing up. If I used a local mechanic, I may have been able to solder Al (specific skill) or replace a section with tubing and clamps. When I thought about the inconvenience of a leak in the middle of nowhere vs no rear heat and getting it fixed that day, I went for the by-pass solution. No leaks, but no rear heat (other than recirculating the front heat through the rear blower which still works.)

- , Ottawa, Ontario, canada

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