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Discussion Starter · #1 ·
There is a Ford Quality Care Center just up the street from my work. After work yesterday I drove over and took the service rep for a ride while 2920 was still cold. Right on cue at 3000 RPM the death rattle did its thing. He looked a little surprised and said he wasn’t too sure what it was. I made an appointment for this morning for 2920’s 12,000 mile servicing and he said they would let it sit all day and listen to it again when I got off work. Before I got there the rep (who used to be the rattle and vibration specialist at the main dealership) and the lead mechanic (this guy also teaches Auto Mechanics at the local college) took the car for a ride and listened to it. (3 miles – I checked!) When I got there 2920 was up on the lift and they were looking at it. They said the same thing Driving Simulator mentioned once in an earlier thread - harmonic resonation. They also noticed the “under-load” difference. They explained that when under load the engine twists against the mounts and may be causing something to touch something else. They both seemed very interested in figuring out what it was that they heard. I asked about detonation, pre-ignition and piston slap and they both said no, they think it is something else. The rep said that first thing tomorrow he was going to check the Ford service web site for any info on the problem he could find. That’s when I told them about Bullitt Club and that a good percentage of Bullitt owners are having the same problem. After he checks with Ford they want me to leave the car again so they can attach a ‘chassis vibration analyzer’ and pin point exactly where the sound is coming from. He says they attach an array of microphones to various locations on the chassis and attach them to a ride along computer. It compares the volume of the noise and shows its exact location. Pretty cool. Again, something like what D.S. was doing. Long story, but we'll see what happens!
 

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Puhleeze keep us posted! I've got the death rattle and all symptoms are exactly the same as everyone else. I've been trying to keep it under 3K while it's cold but it still sneaks up there. Sounds like you've got some guys who are truly interested. I am planning to move down to your area (Rio Rico) in the next couple of months so I'll be interested to find out where your dealer is, etc. Thanks for the info. Tony
 

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<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2002-02-19 23:03, JohnHenry wrote:
They also noticed the “under-load” difference. They explained that when under load the engine twists against the mounts and may be causing something to touch something else. </BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

If these guys can explain how this relates to the temporal and temperature dependence i'm a monkey's uncle...

But i have to agree that the noise sounds like its right on top of the engine and may simply be something rattling. Afterall Art Hyde had told me via email that it may be injectors/fuel rail vibrating and making a noise (due to a standing wave).

At least they aren't gonns stuff a new motor in it for no reason.

I guess i have to go on down to Tucson for good service.
 

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Excellent work John. The first step is locating the source of the noise. The array microphone system should be able to locate the source in 3D. If they have standard sample points (with calibrated locations), it's just a matter of hooking up the mics and telling the computer where they are located (reference point 1, 2, 3, etc.). Otherwise, they'll have to calibrate the mics to their spatial locations (x,y,z, etc.).

The next trick is pulling the sound out of the background noise. The sound in my recording occurred at ~3500 RPMs, and the peak frequency response occurred around 4kHz. Thus, at 3000 RPMs, the sound might be strongest at just under 4kHz (perhaps not linear, and perhaps not even directly correlated). A 3D FFT plot can show this. Sounds like some cool hardware and software. If you get a chance, please post who makes the audio/sensor package.

Again, excellent work. Please post any more info.
 

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Wow, you have a dealership who cares, and wants to do everything possible to rectify this on-going problem. That is great news! I hope they find the problem. Please keep us posted on the outcome. Thanks
 

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Keep us posted. I would really like to know what the noise is.....

I would also like to know why my '00 F150 with the 5.4L made the exact same noise at roughly the same RPM when cold too, if it isn't piston slap.....
 

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Discussion Starter · #7 ·
<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2002-02-20 01:43, DrivingSimulators wrote:
Excellent work John. The first step is locating the source of the noise. The array microphone system should be able to locate the source in 3D. If they have standard sample points (with calibrated locations), it's just a matter of hooking up the mics and telling the computer where they are located (reference point 1, 2, 3, etc.). Otherwise, they'll have to calibrate the mics to their spatial locations (x,y,z, etc.).

The next trick is pulling the sound out of the background noise. The sound in my recording occurred at ~3500 RPMs, and the peak frequency response occurred around 4kHz. Thus, at 3000 RPMs, the sound might be strongest at just under 4kHz (perhaps not linear, and perhaps not even directly correlated). A 3D FFT plot can show this. Sounds like some cool hardware and software. If you get a chance, please post who makes the audio/sensor package.

Again, excellent work. Please post any more info.
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>


Ok, I'll find out all I can about their equipment. With your permission I would like to print your reply above (frequency and RPM info) and copy your sound file and give them to the service guys. As soon as I get off work I'll go over there and see what they found from Ford.
 

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<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2002-02-20 10:39, JohnHenry wrote:
<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2002-02-20 01:43, DrivingSimulators wrote:
Excellent work John. The first step is locating the source of the noise. The array microphone system should be able to locate the source in 3D. If they have standard sample points (with calibrated locations), it's just a matter of hooking up the mics and telling the computer where they are located (reference point 1, 2, 3, etc.). Otherwise, they'll have to calibrate the mics to their spatial locations (x,y,z, etc.).

The next trick is pulling the sound out of the background noise. The sound in my recording occurred at ~3500 RPMs, and the peak frequency response occurred around 4kHz. Thus, at 3000 RPMs, the sound might be strongest at just under 4kHz (perhaps not linear, and perhaps not even directly correlated). A 3D FFT plot can show this. Sounds like some cool hardware and software. If you get a chance, please post who makes the audio/sensor package.

Again, excellent work. Please post any more info.
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>


Ok, I'll find out all I can about their equipment. With your permission I would like to print your reply above (frequency and RPM info) and copy your sound file and give them to the service guys. As soon as I get off work I'll go over there and see what they found from Ford.

</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

Take what you need. Also check out the lastest .wav sounds posted under a new thread on this BBS.
 

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Glad I saw this post. This is one of the reasons my 01 cobra is in the shop. Somthing rattling on the chassis is much better then it being somthing internal. Hey you sound like you got a great service dept. Keep us updated.
 

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John Henry - One question, (because my 01 Cobra has identical symptoms) Do you or the mechs think that this may also be the cause of the initial start up knock that alot of us get. My death rattle doesn't occur in warm weather but that 1-2 sec start up knock is always there if the car sits for any time.
Thanks.
Reg
Ohio
 

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<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2002-02-21 19:17, 1stCobra wrote:
John Henry - One question, (because my 01 Cobra has identical symptoms) Do you or the mechs think that this may also be the cause of the initial start up knock that alot of us get. My death rattle doesn't occur in warm weather but that 1-2 sec start up knock is always there if the car sits for any time.
Thanks.
Reg
Ohio
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

Start up knock sounds like classic piston slap. This rattle sound could be something else.
 

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Discussion Starter · #12 ·
Here’s an update on what’s happened so far. I went back yesterday and they said their net connection was down and to come back after work today. The rep was on the Ford service database when I got there. He searched for about an hour until he eventually gave up. Tomorrow they are going to call their Ford service hotline to see if anyone has seen and solved this problem yet. If they don’t get any info from them then they want me to leave 2920 in the morning early next week, let it sit all day, hook up the mics and take it for a rattle-ride.
I asked the vibration guy about the analyzer. He said the one they have at the shop is not as sophisticated as the one the mechanic was describing. It is called “chassis ears” and made by Steelman – not sure of the spelling. It has an array of microphones that attach anywhere you want them and are connected to a switch box. The operator uses a headset and switches between the microphones listening for the loudest sound. They can then reposition the mics around that area and do it again until they find the source of the noise.
One very cool thing about this experience – every time I go over there 2920 attracts attention. Lots of positive comments and questions. I will post again as soon as I have more news.

1stCobra: I’ll ask them if they have heard anything about the start up knock.

Dennis: Are you up for a visit?
 

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<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2002-02-21 23:58, JohnHenry wrote:
Tomorrow they are going to call their Ford service hotline to see if anyone has seen and solved this problem yet.

</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

Gee, i wonder what they'll recommend, a new motor maybe?

just a guess....

this is extreme sarcasm, by the way.

The hotline has, to my best estimate, recommended replacing hundreds of new 4.6l engines for this noise--for no reason because the new ones do the same thing.

Trust me, i know from experience.

Be weary of this engine replacement crap. If they pull this on you ask to see the service manager and have him go for a ride with a few Gt's off the lot to listen for the noise.

I did this and two new gt's in this dealer's inventory rattled.
 

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<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2002-02-21 19:17, 1stCobra wrote:
My death rattle doesn't occur in warm weather but that 1-2 sec start up knock is always there if the car sits for any time.
Thanks.
Reg
Ohio
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

This is for Jeostang as well: A local Mustang club here in AZ has a couple of 99+ Cobras that have some start up knock when cold.

These guys run their cars harder than i ever dare run mine and have over 20 k miles on them.

I heard that the Aluminum block makes the noise more audiable than usual. I probably have it in my Gt.
 

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when you go back to the dealer, can you ask the rep why they rated our cars at 265hp and 305 lbs of torque?

I haven't found anyone who could tell me why after adding a new intake and better throttle bodies among other upgrades we only rate a 5 horse diff and just a little more torque.

I know what the dynos say but i am interested in what the rep says.

thanks
 

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Discussion Starter · #18 ·
<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2002-02-22 19:13, fixer wrote:


Gee, i wonder what they'll recommend, a new motor maybe?


</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

You are exactly right Fixer. When he said they were going to call I thought “oh no… What are they going to recommend?” I would much rather have them approach this cold without any bugs being dropped in their ear. But they explained that this is the protocol they have to follow. When I stopped by today they were just leaving. The rep had called the hotline earlier in the day and said the person he talked to had no clue. They said they would call him back but did not. Just as well really. I suggested that we just go ahead with the test. They agreed and set me up for Tuesday morning with the understanding that they don’t start unless I am there. Figure I’ll take the digital camera and get some pictures to post. More later.
 

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JohnHenry,

I think most of us with this issue are just about willing to move to your location so we can use your same people. You seem to have found the ONLY INTELLIGENT servic group that is willing to take notice that something is wrong. Definitely keep us posted.
 

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This reply is to FIXER you are correct an engine swap will not fix anything! 1345 is not making the noise but the service writers (who works at the same dealer I do) 01 GT was making the noise and our FORD rep said "replace" The problem is no "NEW" engines only reman. We searched and found a new one in a reman box, installed it and guess what more death rattle, he is now looking at a 02 with out the rattle! He is to say the least P'ed.
jacob67 I talked to one of the members from TEAM MUSTANG at Commerce at the MCA 25th show he said it had to do with the cobra guys and they didn't want to get into a probelm like the under powered cobras a few years back. He said quote "add the pulleys,intake,throttle body,exhaust and you do the math and forget about what is printed" That is the explanation I got.
Tony
 
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