SOLVED! Loud roar , speed related.

kenzoil

Active Member
I have a 08 trailblazer, 4.2L 6. Upon driving I hear a very loud roar, that is speed related. When slowing and braking the noise "winds" down accordingly. I have replaced the fan clutch, and the emissions valves, solenoids, and air pump are all functioning as they should. I seem to notice that when traveling down the highway if I turn the steering wheel to the left the noise goes mostly away. When I bring the wheel back to the straight position the noise resumes and gets somewhat louder upon turning the steering wheel to the right. I had a 07 trailblazer and had to replace both wheel bearings, but I don't recall the loud roar noise, but more of a gravely sound. Could this still be a wheel bearing, or is it transmission or drivetrain related?? Also, I noticed the engine rpm is functioning properly. Any help would be appreciated.
 

Sparky

Moderator
Sounds like a hub to me. Likely left one, but if both are same age just do em both.
 
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kenzoil

Active Member
So even though it sounds like a fan clutch roar to me, it is probably the left wheel hub??
 

TJBaker57

Well-Known Member
Actually...some have experienced the opposite side. Noise at turning right can mean right hub fail. I had this on my Yukon, thought it would be the wheel on the outside of a turn but it turned out to be the inside.
 

budwich

Well-Known Member
IF it is a fan clutch, then when the issue shows up and you slow down "immediately" so that you can carefully place the gear selector into neutral and increase idle again (ie. not in gear), does the noise again increase? IF not, then it is unlikely to be a fan problem. IF so, then potentially an issue with the fan.
 
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kenzoil

Active Member
well, I bought one hub, and if you had the choice, which would you replace? Planned on doing this tomorrow. All I know for sure is, sound lessens to almost nothing on turning steering wheel to left.
 

budwich

Well-Known Member
my method is take off the wheel and brake caliper (hang it from a support somewhere). Put on a couple of lug nuts to hold the rotor in position. Turn the rotor by hand and listen / feel what's up. You will likely feel and hear noise IF the bearing is as bad as you indicate. You can confirm by doing similar test of the other side. Yes it is more work but not as much as pulling the hub..... but that is my take on time, money, and effort. I actually pulled a good hub and ultimately reused it as the replacement didn't last... I had bought two at the time due to price... but you kind of get what you pay for... maybe although in car parts these days, its all over the place in terms of "real parts".
 

Mooseman

Moderator
Fan clutch issue would be directly proportional to engine speed, not road speed. So far, this does indicate a hub problem.
 

TJBaker57

Well-Known Member
I agree with Budwich. Jack them up and closely check both sides before deciding. Only additional thing would be check even before removing the wheel, spin the wheel/tire and listen. Also grasp the tire and try to wiggle, see if there is noticeable play.
 

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