Clacking noise when taking off or driving slow at low rpms(manual)

[Mad Elliott]

Hey, I've been having a clacking noise on my 06 Mustang GT w/ manual trans. The best way I can describe noise is a metal sounding repetitive clacking that only happens when driving slow at lower RPMs (1500-2000 or so) and when taking off slowly. Sounds like it's coming from underneath the car (could be wrong) and performance of the car doesn't seem affected at all, no noise at higher RPM's and the car will still shit 'n get on demand. I've read several other posts but none seemed to describe exactly what I'm experiencing. Any help would be much appreciated. Could it be something to with the clutch, vct, or timing tensioner? Btw this is my first post, I've been using this forum for about 2 years (since I got the car) but only recently made an account. I have used this forum to solve other problems but this one I'm being more thorough with because the clack sound is pretty concerning. I'm leaning towards it having something to do with the clutch but I'm really not sure, there's no other symptoms and I'm pretty good about not riding the clutch. Idk if I would consider this another symptom but I think there's an exhaust leak I need to check and get it fixed, I didn't think that would be related though but worth mentioning. Car has 124k miles on it.

Mods(that I'm aware of from previous owner): BBK cold air intake, catback flowmaster exhaust, potentially a tune(91?)

I think it's worth mentioning that I didn't have any problems until I moved to Phoenix, AZ from Tulsa, OK. I drove the car 1,100 miles in one day. No immediate problems from the drive though, it's just the atmosphere is very different here, it's very dry and hot compared to Oklahomas mid temp humid climate so I was wondering if a tune could cause any issue because the air being so different here.

 

[Mad Elliott]

I want to add that the noise only happens when it's hot outside and the car is hot. The noise happened earlier today when it was 100 degrees outside and I was driving around, just now I went and drove it at night, the temperature was now about 70 degrees outside and it didn't make the noise even when I was intentionally trying to replicate it.

 

[ChewyR]

I would suggest watching a few you tube videos on the 3v phasers and see if that matches what your hearing. If its not that I would lean towards an exhaust leak.

 

[Mad Elliott]

I would suggest watching a few you tube videos on the 3v phasers and see if that matches what your hearing. If its not that I would lean towards an exhaust leak.

I watched some videos like you said and I don't believe that's the problem I have because I haven't heard the noise at idle even while listening with the hood open I can't hear anything. It seems to only happen when letting out on the clutch and accelerating slowly or driving slowly right afterwards but no idle noise. I'm not ruling anything out though, anymore insight would be appreciated.

 

[Mad Elliott]

The noise could also be described as a rattling noise if that helps. Another forum I read says it could be bad COP. I was actually planning on replacings the coils and plugs this week because I've been having a misfire problem too. Could this be a cause?

 

[skwerl]

Somebody put a zip tie on your driveshaft?

 

[Mad Elliott]

Somebody put a zip tie on your driveshaft?

I highly doubt that, it's not a constant noise when driving, won't even do it when it's colder outside and the car is cold. Besides my car is low enough someone could get their hands that far under.

 

[1950StangJump$]

Two “simple” possibilities come to mind ....

I had a clacking under certain loads — ended up being part of the aftermarket mufflers’ innards that had broken free. Sounded like a wrench being tapped against glass. New mufflers = no more noise.

Secondly ..... in 05-06, Ford had used exhaust hangers at the mid-pipe that caused noise resonance into the cabin. If the customer complained, they simply had the servicing dealer remove the hanger — allowing the exhaust to hang “free” from the headers back to the mufflers’ hangers. By 2007ish, they stopped using the hangers from the factory and all the exhausts hung free from header back to mufflers. I’d be curious as to whether yours are still there.

 

[Mad Elliott]

Two “simple” possibilities come to mind ....

I had a clacking under certain loads — ended up being part of the aftermarket mufflers’ innards that had broken free. Sounded like a wrench being tapped against glass. New mufflers = no more noise.

Secondly ..... in 05-06, Ford had used exhaust hangers at the mid-pipe that caused noise resonance into the cabin. If the customer complained, they simply had the servicing dealer remove the hanger — allowing the exhaust to hang “free” from the headers back to the mufflers’ hangers. By 2007ish, they stopped using the hangers from the factory and all the exhausts hung free from header back to mufflers. I’d be curious as to whether yours are still there.

I'm taking it to the exhaust shop on monday because I'm certain there's a leak. I'll update afterwards.

 

[Jbarker83]

i to notice a metal type of buzzing noise from either the dash or under the car near the dash like a heat shield type sound only happens when accelerating at low speed got a 05 gt convertible

 

[Mad Elliott]

i to notice a metal type of buzzing noise from either the dash or under the car near the dash like a heat shield type sound only happens when accelerating at low speed got a 05 gt convertible

It's possible I'm hearing a heat shield or busted exhaust. I'm changing spark plugs and boots tomorrow morning and then taking it to the exhaust shop I'll update on what I find out.

 

[Jbarker83]

I don't see anything loose under my car. I also wondered if it was my aftermarket radio vibrating I did notice since removing the factory I can hear alot more engine noise in the cabin kinda annoying never had a car so that when changing the radio

 

[cavero]

Stock 2 piece driveshaft? Wondering if maybe the CV joint in the middle

 

[CammedS197]

You have cats?

 

[nbk13nw]

I had a rear pinion seal go bad, it never made a sound during the summer, but during the cold months it squeaked like hell. Took two heat / cold cycles to figure it out. Also the read upper mount on the rear end made a loud clunking sound at slow speed and over bumps . May want to inspect it.

 

[MrBhp]

Sounds like valve ping/detonation. If it only happens when you lug the engine and accelerate, I'd bet on detonation.

 

[Mad Elliott]

Stock 2 piece driveshaft? Wondering if maybe the CV joint in the middle

You have cats?

I had a rear pinion seal go bad, it never made a sound during the summer, but during the cold months it squeaked like hell. Took two heat / cold cycles to figure it out. Also the read upper mount on the rear end made a loud clunking sound at slow speed and over bumps . May want to inspect it.

Sounds like valve ping/detonation. If it only happens when you lug the engine and accelerate, I'd bet on detonation.

Yes, stock 2 piece driveshaft.
Yes, cats
Rear pinion seal was replaced 2 months ago the noise doesn't sound like it's coming from the rear end though.

Alright so I changed the spark plugs and boots and then took it to the exhaust shop and had the leaks fixed and did a muffler delete because both mufflers were rusted and shot. The car runs and sounds a lot better now but after driving and warming up the car it still has the rattle. Tomorrow I'm getting it on the rack at the shop I work at and having the lead tech inspect it. I'm leaning towards driveline issues but I'm curious about how to diagnose the detonation problem and what does that mean?

 

[Mad Elliott]

Sounds like valve ping/detonation. If it only happens when you lug the engine and accelerate, I'd bet on detonation.

https://www.s197forum.com/threads/detonaton-issues.18017/#post-270758
^ Could this be my problem?

 

[ChewyR]

It could, and octane boost or seafoam is like 10 bucks. Personally I wouldn't describe mild pinging as clacking, but raising octane (I put a couple gallons of race gas in) is easy and cheap. Without hearing it very tough to say. Could even be the AC clutch.

 

[Mad Elliott]

It could, and octane boost or seafoam is like 10 bucks. Personally I wouldn't describe mild pinging as clacking, but raising octane (I put a couple gallons of race gas in) is easy and cheap. Without hearing it very tough to say. Could even be the AC clutch.

I'm going to do a full diagnostic tomorrow but is it possible to test if it's the AC clutch by simply turning off the AC and putting the car under the same conditions as when it makes the noise?