My 2004 Chevy Trailblazer is making a bizaar noise when I start it up. It's starts as a high pitch squeal then drops to a lower pitch squeal then ends in kind of a grind. Thought it was a slipping belt but there's only one belt and it's fine. It runs fine and the noise dies away after the engine settles. It only makes the noise on start up. If you cut off the engine before it settles down - the noise continues, so it doesn't stop with the engine. Seems to be coming from inside the engine itself.

SOURCE: Front end noise

Sounds like rust build up on the rotors,this is a common problem with after market rotors,or it is a squealer tab and they squeal to warn you before damage is done to the rotors when brake pads are 2/3 worn down.have a brake inspection done.

SOURCE: My 2004 Chevy Trailblazer dies when I turn on the air conditioner

just check weather all spark plugs are ok, even if one misfires then turning ac on will stop the engine. during motion the ac manages to get the power from other plugs. i hope this solves ur problm.

Jerry Koski

• 443 Answers
• Posted on May 13, 2009

SOURCE: grinding noise front end

its either your front brake pads or your CV joint is going bad .. Jerry

SOURCE: I have a 2004 Chevy Trailblazer LS with strange noise.....

If it is making a noise in the belt area, have them check the water pump. These get loose water pump bearings that cause belt noise.

SOURCE: high pitch squeal and grinding noise from rear when

Rear brake caliper bracket bolts frozen,
Replace the braket boots and relube.