Check Engine Light and/or Excessive Fan Noise on Chevrolet Trailblazer

Problem Description and Possible Solution

The cooling fan clutch may fail causing excessive fan noise and/or the Check Engine Light to illuminate.

Problem Data
RepairPal Verified
Average mileage: 130,847 (12,000–230,000)
Engine affected: 4.2L 6 Cylinder
6 model years affected: 2002, 2003, 2004, 2005, more2006, 2007
126 people reported this problem
Viewing 1 - 20 of 55 comments
One day I noticed a loud whining noise from my under my hood while accelerating. At first I thought my transmission or motor was acting up, I got scared. A few days later, my check engine light came on. I took it to a car parts store to get the engine light scanned and the codes indicated was pump motor circuit open and fan high speed. I have not fixed this problem yet, just researching some sites to see what this problem could be but it looks to me that the fan clutch is or went bad. Any suggestions?
I fixed both issues by cleaning the electric clutch connector on top of the radiator
while accelerating through the low gears, the engine sounds like it's ready for take off
There is a loud humming noise from under hood-- shakes and vibrates when started up and at stoplights... transmission feels like it was slipping, would go to 3,000-3,500 rpms before shifting gears, terrible gas millage--

Found out it was the electronic clutch fan-- dealership wanted $400 for part, with 3 hours for labor,
found the part at autozone for $199, saved a couple hundred bucks---vehicle runs alot better and gas millage has gotten alot better
Check engine light stays on fan clutch running to fast make noise at sometimes
Have replaced the fan clutch twice since buying the vehicle used in 2004. Eventually had to replace the transmission too and suspect it was due to not replacing the fan clutch soon enough and driving it that way too long.
I would drive down the street sounding like I was driving a jet. Fan clutch was bad. Got it replaced cost $90.
Loud fan noise and reading really high rpms
bought new clutch fan at autozone for $200. installed with my son in about 2.5 hrs. dealer wanted $800 for same job.
Vehicle sounded like an airplane taking off when RPM was increased. Had just had water pump replaced due to bad bearings, making the fan wobble. Less than 100 miles later, fan clutch failed in the "on" position and would not disengage. Had to replace fan clutch at about $450.
Check engine light on and loud noise in rear fan
bearings in the water pump went out. now at 165000, fan clutch is going bad.
replacing fan clutch. At the shop right now. $800 at the dealer WOW A friend was visiting last week and has a Honda Accord. 2008 with over 100k miles. He bragged all he's done is oil changes and one set of front brakes.??
It makes me think because I've had several good size repairs on this Trailblazer already.
The fan is making a very loud squeaky noise
Load fan noise
It has happened twice in 120,000 miles
Fan clutch making loud noise with increase of RPMs eventually seized up and tour brand-new water pump away from motor shooting fanblades everywhere replaced everything. Still makes the loud rev
144,000 miles and clutch fan went out again. this is the 4th one to put in by dealership and Mollee Chevrolet put last one in 11-6-2014 went out 11-8-2015 they will not warrenty it and want $1000.00 to fix it again. Advance auto can get the part for 188.00.
severe vibration no one can diagnose for 4 yrs now.
Dealership has put in motor mounts and tranmission mounts clamps on the exhaust.It just shakes in gear out of gear.
2nd fan clutch installed within 18 months