Bought a 1998 Mustang! But, need some help with an acceleration sound I'm hearing...

TCHouston713

New Member
Jul 27, 2018
8
1
1
35
Houston, TX
Hi Everyone,

I am excited to say that I finally bought a Mustang, after always wanting to since I was a kid. Anyhow, I bought it today and it has 101k miles on it. When I lifted up the hood, the engine looked to be in great condition. The downside is that the car needs a new paint job, but besides that, everything else seems okay, considering that it is a '98.

An issue I noticed was/is that when I accelerate, I hear a sound coming from the passenger side, under the hood, that sounds like a weed wacker operating when I accelerate. When I stop accelerating, it stops, and the car seems to coast/cruise along fine, without sounds. The car also idles without problems.

Truth be told, the car seems to drive fine, except for the weed wacker sound when I accelerate. AFAIK, the car has been sitting on the used car lot for some time, so I think it could just need an oil change and possibly something else?

Before I make a mental catastrophe in my head over what could be wrong, I wanted to ask you fine folks what the problem might be. Again, when I accelerate it sounds like there is a weed wacker coming from the right side of the engine (but, it's not overly loud...more like a faint weed wacker).

Thanks again!
 
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GDawg

Founding Member
Mar 22, 2002
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Colorado Springs, CO
Check to make sure your serpentine belt isn't rubbing anything. When you accelerate the engine slightly moves due to torque so the belt may be making contact with something, a harness wire, a hose... Look for anything too close. I've had to tie wrap stuff up to keep them away from my belt but then I have a supercharger so I have things in weird places.
 

wmburns

SN Certified Technician
Aug 14, 2009
5,842
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Houston Texas
Can you post a video of the sound? Some things come to mind:
  • Is this a V8? If so consider spark plug blow out? Best to catch BEFORE it actually damages threads. Re-torque to factory specs.
  • Broken motor mounts allows excessive motor movement.
 

TCHouston713

New Member
Jul 27, 2018
8
1
1
35
Houston, TX
Can you post a video of the sound? Some things come to mind:
  • Is this a V8? If so consider spark plug blow out? Best to catch BEFORE it actually damages threads. Re-torque to factory specs.
  • Broken motor mounts allows excessive motor movement.
Hi,

It is a V6 3.8L engine, but I wouldn’t mind if it was a V8 ;-). I have the car at the mechanic now; He will be changing the oil, plus listening for the sound.

I’m unable to make a video of it at this moment, but the best way to describe it is the sound of when kids used to put baseball cards in their bike spokes, or the sound of a weed wacker whipping around (sorry, not trying to beat a dead horse with the weed wacker comparison).

The shop I am at got good reviews, so hopefully they can end my torment and deduce what the problem is and get the Stang and I back on our ways!

(Inspirational music plays in background)

Thanks again :)
 
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TCHouston713

New Member
Jul 27, 2018
8
1
1
35
Houston, TX
Well, I took it to one shop and the guy said he didn't notice anything abnormal and to give it time to let the fresh oil circulate through the engine. I then took it to a second shop and the mechanic said that my rotor was shot on the passenger side, and he fixed it. It is now better, but I hear the sound, although it sounds better than before.

I'm unsure if I am just being too neurotic and am over-analyzing the sounds the car is making. Since I've only driven sedans up to this point in my life, I'm used to the "plain jane" sounds of an engine. Also, the second mechanic has operated his repair shop since 1995 (before the car was built), so I assume that he would have been able to diagnose something if it was wrong in the engine...Or so I hope...? ;-)

Should a '98 Mustang sound like any other V6 engine out there? Or do Mustang engines have a slightly unique sound when being driven? I realize this might be an odd question, but I know that certain cars have their own "personalities" and wasn't sure if I'm paying too much attention to something that currently isn't a problem.

Thanks again.
 

GDawg

Founding Member
Mar 22, 2002
1,463
19
58
Colorado Springs, CO
What "rotor" was the mechanic talking about? Our cars (at least these years) have coil packs that are solid state (no moving parts). I'm always very weary of mechanics and being ASE certified myself, I usually know when they are lying to me.
 

TCHouston713

New Member
Jul 27, 2018
8
1
1
35
Houston, TX
He said it was the passenger side rotor.

Believe me though, I know the feeling of not trusting most mechanics :-(, that's why when I find a good one I tend to return to them (new in town currently, so am still looking...besides one mechanic that I already know of besides the guy I went to yesterday).
 

Neuron

Mustang Master
Nov 6, 2016
795
173
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The disc brake rotor, it should have made a difference in the sound when applying the brakes usually if there is a problem there. Try to get a recording of the sound.
 

TCHouston713

New Member
Jul 27, 2018
8
1
1
35
Houston, TX
I tried to upload the sound, but it said that the uploaded file does not have an allowed extension and I couldn’t upload it. I recorded the audio on my iPhone...
 

TCHouston713

New Member
Jul 27, 2018
8
1
1
35
Houston, TX
Thanks! I think that it might be a broken flex plate (or fly wheel?). I listened closer and it seems that the sound is coming from the right front wheel and is loudest when I accelerate, then quiets down when I coast/cruise.
 

08GT500

Active Member
Jul 12, 2018
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Massachusetts
H

It is a V6 3.8L engine, but I wouldn’t mind if it was a V8 ;-). I have the car at the mechanic now; He will be changing the oil, plus listening for the sound.

I’m unable to make a video of it at this moment, but the best way to describe it is the sound of when kids used to put baseball cards in their bike spokes, or the sound of a weed wacker whipping around (sorry, not trying to beat a dead horse with the weed wacker comparison).

The shop I am at got good reviews, so hopefully they can end my torment and deduce what the problem is and get the Stang and I back on our ways!

(Inspirational music plays in background)

Thanks again :)
Hope you found your issue and the Shop was light on your pocket. If you hear a noise, go with your gut- there is no unusual sound a stock V-6 98’ Mustang should makes vs any other Car.
One thought regarding your issue. Being High Mileage, & Noise described, it May be a slight Passenger side exhaust Manifold gasket leak or connection. Some small leaks heard only under a load while driving, but you may be able to replicate, Start it & open the Hood, warm it up- and rev it up, standing above the Passenger side Bank. If that’s the culprit, you may hear it, see a small black Carbon leak around the Gasket, Pipe joint. 75% issues are ‘Occam’s razor’ with Mustangs.
.If this is the issue, it will affect performance and should be addressed when possible. In addition, being a 1998 (an OBD-2), which means the CPU diagnostics help locate issues better, easier VS. 82-95’ Mustangs. It’s nice to have a decent Scantool, (Not expensive) .Plugs into the diagnostics port under the Drivers side dash, Cheap and effective
Get yourself a Chiltons or Haynes Tech Manual and familiarize yourself with the Car, Money well spent!. Good luck!
 
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TCHouston713

New Member
Jul 27, 2018
8
1
1
35
Houston, TX
Hope you found your issue and the Shop was light on your pocket. If you hear a noise, go with your gut- there is no unusual sound a stock V-6 98’ Mustang should makes vs any other Car.
One thought regarding your issue. Being High Mileage, & Noise described, it May be a slight Passenger side exhaust Manifold gasket leak or connection. Some small leaks heard only under a load while driving, but you may be able to replicate, Start it & open the Hood, warm it up- and rev it up, standing above the Passenger side Bank. If that’s the culprit, you may hear it, see a small black Carbon leak around the Gasket, Pipe joint. 75% issues are ‘Occam’s razor’ with Mustangs.
.If this is the issue, it will affect performance and should be addressed when possible. In addition, being a 1998 (an OBD-2), which means the CPU diagnostics help locate issues better, easier VS. 82-95’ Mustangs. It’s nice to have a decent Scantool, (Not expensive) .Plugs into the diagnostics port under the Drivers side dash, Cheap and effective
Get yourself a Chiltons or Haynes Tech Manual and familiarize yourself with the Car, Money well spent!. Good luck!

Hi,

I forgot to update this post...I saw a different mechanic and he said that it is due to an issue with the catalytic converter (a broken piece sticking up or something). He said I hear the sound when I accelerate since the exhaust flows over it, rattling it around, but when I cruise/coast, the flow is low enough that it doesn't make a sound. His boss then gave me good news/bad news, saying that the good news was that my car would pollute more exhaust than necessary (I'm sure environmentalists would have been thrilled to hear that! ;-) ), but it didn't pose a major issue right away to the car. But, the bad news was that he would need to repair the entire catalytic converter and it wouldn't be cheap to do (all that was missing when he said that was a flash of lightning in the window behind him and an evil smirk). I then called a more trustworthy mechanic, and he said that a catalytic converter repair should be able to be done for around $350 (this mechanic works out of his house and isn't a repair shop, per se, like the first mechanic).

Either way, I'll take the Stang to a mechanic once it gets out of the paint shop. Part 1 of 2 with the car was "image enhancement", since the paint job was looking pretty crappy since it may have been the original paint job. But, hopefully the fine folks at Maaco can make the car look decent again (and by hopefully I mean, they better! ;-) )