Right after I start up my Colorado when the engine is cold, a loud squealing noise appears for a couple minutes. It sounds sort of like a bad serpentine belt, but the noise is actually coming from the high pressure fuel pump. Dealership claims this is normal and is documented in bulletin #07-06-04-025L. However, the high pressure fuel pump in the 2015 and 2016 Colorados don't make this noise, so it is hard to believe this is normal.
A D V E R T I S E M E N T S
Right after I start up my Colorado when the engine is cold, a loud squealing noise appears for a couple minutes. It sounds sort of like a bad serpentine belt, but the noise is actually coming from the high pressure fuel pump. Dealership claims this is normal and is documented in bulletin #07-06-04-025L. However, the high pressure fuel pump in the 2015 and 2016 Colorados don't make this noise, so it is hard to believe this is normal.
- pixelpunch, Round Rock, TX, US