accordionfolder
accordionfolder UltraDork
8/27/24 6:58 p.m.

Any tips for narrowing down which accessory is screeching on my '18 2.5 turbo CX-9? 

Should I invest in a mechanic's stethoscope or is there another way of figuring it out?

It's so loud and high pitched I can't tell where it's coming from. Same A/C on/off - I **think** it's a bearing in the alternator, but like I said - it's super hard to tell.

Thanks! 

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
8/27/24 7:15 p.m.

"Invest" :) $7.99. I think it's probably the easy button here.

https://www.harborfreight.com/mechanics-stethoscope-63691.html

I've seen people fake a mechanic stethoscope by using a long screwdriving and holding it against their head, but...$7.99.

 

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
8/27/24 7:18 p.m.

A screwdriver works a lot better.  I used to have a stethoscope, I always gave up and went for a thin 24" screwdriver.

earlybroncoguy1
earlybroncoguy1 Reader
8/27/24 9:41 p.m.

Remove the belt, then clean ALL of the pullies with solvent like brake cleaner, use a wire brush and a screwdriver tip to clean all the way down into the bottom of the grooves. Install new, correct belt (don't waste your money on cheap ones), make sure the tensioner is working right.

I had a belt squeal on my Jeep Cherokee, replaced belt and tensioner, still squealed. Cleaned all the pullies (especially the A/C compressor pulley) using the method described above, an amazing amount of belt crap was stuck down in the grooves of most the pullies. Belt was nice and quiet after that.  

accordionfolder
accordionfolder UltraDork
8/27/24 11:07 p.m.

Oh, the screwdriver trick, duh - free, so I'll start there! 

 

Thanks guys!

Andy Hollis
Andy Hollis
8/28/24 8:41 a.m.

Probably the PS pump...mine went out early on.  Challenging fix unless you have small hands.  But the replacement has been working great for another 150k miles.

NOHOME
NOHOME MegaDork
8/28/24 9:06 a.m.
earlybroncoguy1 said:

Remove the belt, then clean ALL of the pullies with solvent like brake cleaner, use a wire brush and a screwdriver tip to clean all the way down into the bottom of the grooves. Install new, correct belt (don't waste your money on cheap ones), make sure the tensioner is working right.

I had a belt squeal on my Jeep Cherokee, replaced belt and tensioner, still squealed. Cleaned all the pullies (especially the A/C compressor pulley) using the method described above, an amazing amount of belt crap was stuck down in the grooves of most the pullies. Belt was nice and quiet after that.  

Had this same issue. Found it by spreading a bit of silicone sealant on the belt and running the engine.  No need to spread over the entire belt surface, just went for the long easy to get at bits. Squeal went away so knew it was not pulley-bearing related. Removed belt, cleaned all the pulley groves and replaced with new belt. Fixed.

accordionfolder
accordionfolder UltraDork
8/28/24 9:44 a.m.

In reply to Andy Hollis :

Thanks for the heads up! What was the failure mode did you see? 

I'm hoping the screw driver or ear enhancers will lead me to the true issue. It sounds awful but everything is functioning correctly.

dean1484
dean1484 GRM+ Memberand MegaDork
8/28/24 9:53 a.m.

Spray water on the belt while running and see if it changes. If it does it is most likely a belt problem. And if you end up doing an alternator you will be doing a belt anyway so no harm in just doing the belt first.  

accordionfolder
accordionfolder UltraDork
8/28/24 10:30 a.m.

Copy that @dean1484/@NOHOME/@earlybroncoguy1 

It would be even more convenient for me if it's just a funked belt, followed by alternator, worst case would be the power steering (well, not absolute worst case, but you know)

Curtis73 (Forum Supporter)
Curtis73 (Forum Supporter) GRM+ Memberand MegaDork
8/28/24 11:15 a.m.

Skip the screwdriver and stethoscope.  Use a piece of hose, like some extra 3/8" fuel hose.  Stick one end in your ear and point the other end at accessories.  It will isolate the noise down to a 1" radius or less.

accordionfolder
accordionfolder UltraDork
8/28/24 12:22 p.m.

In reply to Curtis73 (Forum Supporter) :

Copy - going out now to try and isolate it!

accordionfolder
accordionfolder UltraDork
8/28/24 12:37 p.m.

A bit o' water on the belt didn't change anything, I tried the hose and screwdriver and I really can't tell where the hell this is screeching from. 

I may "pay the man" at the Mazda dealership for the inspection - since it's probably due for a lot of things. And do what I can with it.

accordionfolder
accordionfolder UltraDork
8/28/24 2:39 p.m.

Took it for an inspection and I was wrong on all fronts, haha - It was the water pump on the back of the engine. 

Looks easy to replace so that's good. 

1988RedT2
1988RedT2 MegaDork
8/28/24 2:47 p.m.

In reply to accordionfolder :

"How many miles on your '18 CX-9?"  Asks the guy with the '19 CX-9.

accordionfolder
accordionfolder UltraDork
8/28/24 2:52 p.m.

In reply to 1988RedT2 :

We're at 103k - no other trouble but oil and tires. 

1988RedT2
1988RedT2 MegaDork
8/28/24 3:25 p.m.

In reply to accordionfolder :

Just over 70k on mine.  It's been great.

accordionfolder
accordionfolder UltraDork
8/28/24 5:01 p.m.

The Mazda dealership had very reasonable rates and was great to work with as per usual, but I figured I can get some tools I've been wanting AND replace the parts - coming out ahead since none of it is particularly difficult (famous last words?). I will report on how that goes. The CX-9 is due for a lot of maintenance items. I'm glad it wasn't the power steering pump.

 

 

accordionfolder
accordionfolder UltraDork
9/3/24 1:32 p.m.

Used this video to get the belt off, the above video to get the water pump off. 

So far pretty straight forward, but getting the water pump off the neck was a bear - strategic wood block and careful pry bar. Replacing the spark plugs, air filters, both belts, and the water pump. First real maintenance since new @103k. Plugs were overdue, same with the air filters. I just had been busy fighting other vehicles. 





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