Squeaking noise underneath my car
Asked by Darren Apr 09, 2020 at 11:29 PM about the 2012 Mazda MAZDA6 i Touring
Question type: Maintenance & Repair
Hey guys I have a 2012 Mazda 6 I Touring
that I just recently bought. And I have
discovered that it makes a squeaking noise
underneath the car. Its not the belts because I
checked those. It's louder under the car than
it is in the engine bay. I did take it to a
mechanic to see what he thought about it and
he said it may be the heat shield. But wouldn't
the heat shield make a rattling sound? Any
thoughts or solutions are welcome! Thanks in
advance.
10 Answers
Also I should add that I can only hear it when the car is in reverse or drive while idling. Sometimes it'll do it in park and neutral but most of the time it goes away when put in those gears.
With the engine running, get a spray bottle and squirt the serpentine belt with plain water. If the squeaking stops for a moment, until the belt is dried out again, it's the belt. If it continues to squeak when the belt is wet it's going to be a pulley. Most likely the belt tensioner or an idler pulley. Hope that helps! Jim
I did this and it still squeaked. Any tips on how to isolate which pulley it is?
You can do the same thing with the pulleys. Set your spray bottle to a stream and spray each pulley in the center with the engine running. Don't worry about the big pulley at the bottom. That's the harmonic balancer and it spins with the crankshaft, not on a bearing like the others. Hope that helps! Jim
Should I pull the belt off and start it and see if it's the pulley? If it still squeaks with the belt off what could it be?
With the belt off you can spin the pulleys by hand. Any noises or free spinning would indicate you swap them out.
Okay thank you! Will be back with an update tomorrow!
Yes, you can run the engine for a few minutes with the belt off. If it still squeaks you need to look for something vibrating, like a motor mount. Hope that helps! Jim
Okay so... I put oil on the pulleys and it was still squeaking. But I noticed that the sound was coming from towards the back of the motor towards the bottom. Near the exhaust. Could it be a failing catalytic converter? My car does smell like sulfur. But do they squeak?
No, a failing catalytic converter won't squeak. But it would trigger the check engine light or service engine soon light and you can also have drivability problems. It could be an exhaust hanger. With the engine running, carefully try to isolate the squeak. The exhaust system gets very hot!! So don't touch it when the engine is running or soon after it's been running!! Hope that helps! Jim
