Two problems related to water pump have been reported for the 2004 Chevrolet Trailblazer. The most recently reported issues are listed below.
The vehicle was purchased new in 2004. Since that time the water pump has been replaced twice yielding a total of three water pumps. As of this writing the vehicle has been solely used for private use not commercial use. We currently have 85,000 miles on it. Three water pumps in 85000 miles is wrong as there is no longevity to the part. The problem was noticed in motion and could have caused severe engine/transmission damage if not stopped iimmeadiately.
I was traveling on the highway when I herd a rattling sound coming from the engine, got off the highway and pull into a station. Call the tow company to tow it to my mechanic he said the water pump bearings broke and the fan stop turning since both are connected together, he said the engine might be damage possible due to overheating. There was no warning of over heating on the gage, water did not leak from the pump. I call gm and they told me to tow it to the dealer for diagnose and they were consider my claim after the diagnose check; they knew my warranty just expired in July. I told them there was know warning of any kind everything was find water pump bearings just broke along with the fan clutch this sample problem cause the whole engine to go bad. If there is going to be a problem with bearings broken on the water pump there should be a warning of this potential problem. Right know I need help to get my truck fix gm denied my case to fix the engine. I believe gm knows there is a problem with these water pumps and serious damage it can cause if they fail.