Metallic raspy rattling sound when accelerating hard above 4000k rpm

[MustangNY]

UPDATE: After letting the car cool down for about an hour and a half I took it back out and I couldnt replicate the sound. Mine situation is exactly like Jossyfilms mentioned. My car is also completely stock. Can be heard with both valves open and closed. IT is definitely coming from the outside and not the interior such as the shifter because it was more noticeable with the windows down and I can hear it coming from outside the car. I am very certain is has something to do with the heat levels and when the car is extremely hot. My theory is that somewhere in the exhaust the heat is causing metal to expand and make slight contact with something else and the specific frequency/resonance at the 4k mark is causing the metal to vibrate against the contact area causing the noise. The fact that it only happens under extreme hot conditions when the oil temp is around 225 and outside temp 85-90, this is my only logical explanation.

Now the question is where specifically this might be happening. Im hoping somebody here who has been under the car and has worked with the exhaust system and knows the ins and outs of the layout and design might chime in. I wont be taking it to the dealership because I know they wont care or bother spending time looking into this as the car drives and performs normally. For most technicians it will probably be the first time even working on a gt350 and I know from experience with not only the gt350 but with other cars, the forum community is the most knowledgeable.

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[Action]

UPDATE: After letting the car cool down for about an hour and a half I took it back out and I couldnt replicate the sound. Mine situation is exactly like Jossyfilms mentioned. My car is also completely stock. Can be heard with both valves open and closed. IT is definitely coming from the outside and not the interior such as the shifter because it was more noticeable with the windows down and I can hear it coming from outside the car. I am very certain is has something to do with the heat levels and when the car is extremely hot. My theory is that somewhere in the exhaust the heat is causing metal to expand and make slight contact with something else and the specific frequency/resonance at the 4k mark is causing the metal to vibrate against the contact area causing the noise. The fact that it only happens under extreme hot conditions when the oil temp is around 225 and outside temp 85-90, this is my only logical explanation.

Now the question is where specifically this might be happening. Im hoping somebody here who has been under the car and has worked with the exhaust system and knows the ins and outs of the layout and design might chime in. I wont be taking it to the dealership because I know they wont care or bother spending time looking into this as the car drives and performs normally. For most technicians it will probably be the first time even working on a gt350 and I know from experience with not only the gt350 but with other cars, the forum community is the most knowledgeable.

Been to the dealer 5 times for this same sound...driving me crazy. Dealers cannot locate the sound.

 

[Competition Orange]

I have something similar too. I've isolated the passenger side brake dust shield as the culprit by putting my hand on anything I could touch last oil change. Sure enough, 1 bolt was practically half backed out. I took the caliper and rotor off, put aluminum antiseize on the mating surface of spindle and shield and also loctite on the 2 8mm bolts holding it on . I'll be doing the same thing to the drivers side as I hear a much fainter yet similar rattle still, but very intermittent.

Well after taking drivers side caliper off and finding no loose dust shield bolts (I still did the same procedure as stated above) I then went to the side rockers and found a total of 3 of the push pins we're coming out, pushed those back up. I then made a rubber barrier between the diff cooler line and rear cooler cover where one of the lines can move and cause metal on metal contact (cooler cover is metal) with no luck.

Same as stated, car has to be hot, starts around 3800ish and is a fast paced buzzing. I'd think a tech in the car on a lift and one on the ground underneath would be able to isolate this easily. If I can't find it with a couple buddies I'll probably take it in.

 

[Jossyfilms]

Talking to my dad he thinks it could be the catalytic converters getting hot and expanding

 

[jefc73]

Exact same for me. Only when car gets hot. Does not do it when I first go out. Has to be something with the exhaust.

 

[mikez]

mine does same thing, i'm thinking it might be the tran's cooler lines touching something and buzzing?? only happens after trans gets warm around 130 or so, usually about 30 minutes of driving. Its the only thing i can come up with, need help at some point to jack car up and have someone hold the throttle at 3800 rpm with me under it
dont think its exhaust, after 5-10 minutes of driving that exhaust is as hot as shes going to get i would think...daily driving it of course

 

[MustangNY]

Hey guys today was a warm day so I figured I'd give it another go and I can still hear the noise. I took her out for about an hour and I first started hearing it after about 45 minutes when the car/engine/transmission is very hot. There is definitely a correlation with components getting hot and this happening at 4k and above. I cant imagine the ones who posted here are the only ones that have this noise. Trying to bump this to see if anyone has identified the issue. Please if everyone can when they get a chance, try to replicate the situation: car needs to be very hot 220-230 engine oil temp. Windows down and at 4k rpm there is a metal rattling sound that seems to be coming from the underneath the car.

Thank you!

 

[Action]

Ford NA is currently looking at my car. Will update with results

 

[_M_]

Ford NA is currently looking at my car. Will update with results

Same thing here. Only from 3800-4000 rpm and it goes away. Last oil change I moved some heat shields around and it stayed clean for a while till it got really hot. I’m fairly positive it’s something to do with the heat shields around the cats. Maybe the cats.

Now that Ford is actually looking at your car maybe we will have an answer. This many owners in a short time, it has to be something. I think it’s a minor thing so I’m not too worried, but I would like to NOT hear it at 4000 rpm.

 

[Action]

The sound is absolutely driving me nuts. This is the 6th time that I’ve had the car in for this sound and after this if they can’t find it I’m going to pursue the lemon law to have Ford buy it back.

 

[MustangNY]

The sound is absolutely driving me nuts. This is the 6th time that I’ve had the car in for this sound and after this if they can’t find it I’m going to pursue the lemon law to have Ford buy it back.

Have you had anything replaced under warranty during any of the 6 visits to the dealership? Only reason I didn't already bring mine into the dealership is because I know they will just say they dont know what it is or won't be able to reproduce it at the time of the technician diagnosing. The whole bringing in the car to the dealership is literally a half a day affair if not longer. I've only owned "luxury" vehicles up until the gt350 and I can say that by far when it comes to service, warranty work or anything to do with the dealership ford is by far the worst. My other concern is the technicians working there. I feel they do not have enough physical hands on experience with the gt350. Majority have never even seen the underneath of one.

I wish ford had some sort of directory with dealerships with certified techs that have actually had the proper experience and training when dealing with the gt350.

Sorry for ranting it's just this issue seems like an easy quick find and fix yet dealerships cant seem to figure it out.

Keep us posted!

 

[Action]

I’ve hade multiple pieces of the exhaust replaced along with various things tightened. No luck so far.

 

[Action]

Just an update. Ford is still looking at the car (have had it for 2 weeks now), and hasn't been unable to track the rattle down so far. Will have another update on Monday.

 

[Competition Orange]

Just an update. Ford is still looking at the car (have had it for 2 weeks now), and hasn't been unable to track the rattle down so far. Will have another update on Monday.

When you go to the dealer maybe mention that there are others with this same issue. Probably won’t help but maybe it’ll get documented by Ford...

Good luck.

 

[blueghost]

I wish ford had some sort of directory with dealerships with certified techs that have actually had the proper experience and training when dealing with the gt350.

!

My dealer is a Roush dealer and has two mechanics that are certified to work on the Roush and GT350s.

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