[DrivingSimulators]

I captured this sample on the way home from work this evening. It wasn't very loud, but it's good enough to show what the rattle sounds like while driving the car (you may need some good headphones to hear the band isolated versions). The sound is peaking right around 4 kHz (pretty close to the RPM when the sound occurred):

http://www.brightland.com/bullitt/bullittrattle.mp3
http://www.brightland.com/bullitt/bullittrattlebandisolated.mp3
http://www.brightland.com/bullitt/bullittrattlebandisolated2.mp3
http://www.brightland.com/bullitt/bullittrattlebandisolated3.mp3
http://www.brightland.com/bullitt/bullittrattlebandisolated4.mp3

 

[Bullitt4995]

Thanks for your time and trouble to record the notorious death rattle, but it was hard to detect in your recordings. :sad:

 

[01GTCOUPE]

DrivingSimulators, you are a genius. Those tracks and results are excellent. I thought that the second one bandisolated.mp3 was ideal. 2,3,and 4 are good too.

I also really got a kick out of bullittrattle.mp3. It's so cool sounding. I may upload it into my Tascam788 and jam over it on my next CD. Getting back to the point...

....You have correctly captured the death rattle of my Bullitt #2095. Thank you for your time and effort. I'm still not overly worried about it, but it p*sses me off if I ever think I want to sell this car. Fortunately, I plan on making it a keeper. I keep telling myself, "Real race cars exibit piston slap 'till fully warmed, Real race cars exibit piston slap 'till very warm..."

 

[TRUBLU#2562]

DrivingSimulators,

Just curious what the screen name means. I am in the simulation business....just curious

 

[DrivingSimulators]

Yes, the sound is subtle in this recording (one recording then filtered as different versions). You will need good speakers (I'm using Mackie HR824's (studio monitors) and Sennheiser 580 Precision headphones). I'm selling all my Mac-based pro audio tools (Pro Tools 24, 888/24 I/O, etc., it's all packed up), and going 100% PC based. I currently only have SoundForge 4.5 for the PC, and its filtering features are limited.

If you listen to the first .mp3, you'll hear a smooth sounding engine, then later you'll here a noisey/rattly/hissy sound. That's the rattle. In the car while driving it's much more obvious. The rattle can be much louder depending on conditions (usually when the air is colder).

I will make a better recording and spend more time "bringing out" and isolating the rattle sound. I still have the capability to record with two electret mics in the engine bay. This takes time and lately I have been very busy at work...

 

[DrivingSimulators]

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2002-02-09 12:56, TRUBLU#2562 wrote:
DrivingSimulators,

Just curious what the screen name means. I am in the simulation business....just curious
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

I'm currently working on two projects: my day job is working on an XBox online title (writing the multiplayer network code). At night, I'm working on a project that I've been working on for a few years: a kinetic energy accurate physics-based driving simulator. I've written CFD-based flight sims in the past, and doing a good driving simulator (that drives like a real car and is still "easy to play") is a great challenge.

So, "DrivingSimulators" is what I hope to be producing in the near future. Here are some shots of the first car test model: http://www.brightland.com/C5R/C5R_TestRender.htm

The driving tech is solid as is the terrain and track technology (all physics computed in the curve domain). I'm working on putting together a complete tech demo (cool track, buildings, signs, etc., cool audio (I'll use the Bullitt's audo for the C5R (I don't have a C5R handy) :wink: )).


<font size=-1>[ This Message was edited by: DrivingSimulators on 2002-02-09 13:21 ]</font>

 

[01GTCOUPE]

I'll have to bring home a pair of anaglyphs from my office to check out your 3-D shots. I'm an optometrist.

Nice work, there, DrivingSimulators!

 

[fixer]

Yup. Thats the exact same noise i'm hearing.

excellent work man.

 

[Dennis]

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2002-02-09 12:47, 01GTCOUPE wrote:
I keep telling myself, "Real race cars exibit piston slap 'till fully warmed, Real race cars exibit piston slap 'till very warm..."
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>
You're crackin' me up! I keep telling myself the same thing too (then I remember that race engines are designed to last, at the MOST, 24 hours ...ie. LeMans, Daytona). I just hope damage is not being done...But mine's a keeper also. LOVE the car...Would never trade it for a blown Cobra or a Mach 1...not even a straight trade.

 

[Dennis]

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2002-02-10 14:46, Reader wrote:
I don't know what you guys are talking about.
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>
Hi Reader,
Do a search or look down a few posts on this forum. You'll see many long threads concerning cold engine knock, death rattle, etc...
About 15-20% of the 4.6 liter engines experience loud knocking between 2,500-4,000 rpm from the time the engine is cold until the temp guage needle reaches mid arc (after about 10 minutes driving). Then the noise is mostly gone for the rest of the drive. Believe it or not, Ford is trying to tell us this is normal.

 

[01GTB]

This is most interesting. I was thrown off by this sound being called a knock. Am I hearing it wrong or is it more of a high frequency popping or rattling? I ask because I jumped in my car yesterday after not driving it for almost a day and got the sound I believe I am hearing in these files. It had never occured before and just happened to be after I bumped the timing with the Steeda T/A. To me it sounds more like a "tinny" sound that resonates through the exhaust.

 

[DrivingSimulators]

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2002-02-11 03:23, 01GTB wrote:
This is most interesting. I was thrown off by this sound being called a knock. Am I hearing it wrong or is it more of a high frequency popping or rattling? I ask because I jumped in my car yesterday after not driving it for almost a day and got the sound I believe I am hearing in these files. It had never occured before and just happened to be after I bumped the timing with the Steeda T/A. To me it sounds more like a "tinny" sound that resonates through the exhaust.
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

The sound does vary from a little tinny rattle sound to a lower frequency rattling sound. The sounds in my recordings are fairly high frequency, and not as loud as they have been when I was not recording. When it gets colder here in San Diego I'll make more recordings (we're having a Santa Ana right now (unusually high temps and winds)).

Since you have a timing adjuster, and you did not hear the sound before, perhaps you could do a test and retard your timing to see if the sound goes away (once you find the temperature and conditions to repeat the sound before retarding your timing).

 

[01GTB]

I will do that in the next few days. I'm also going to email you a couple of MP3s of another vehicle non Mustang that makes a similar sound. I would like you to compare them.

EDIT: I don't seem to see your email. PM me with it if you would like to listen to these MP3's I have.

<font size=-1>[ This Message was edited by: 01GTB on 2002-02-11 05:01 ]</font>

 

[01GTB]

I backed the timing down to 13 degrees on the T/A and it was still present with 93 octane.

 

[cobrar1993]

Your timing still may be to far advanced to eliminate detonation at 13 degrees base setting. My Bullit has had this noise since new and currently has 22000 miles. No changes better or worse. It goes away prior to the temp gauge even moving. I'm a former Ford service manager working for Harley now. This condition appears to be related to detonation or improper timing and fuel curve at that moment untill the engine gets a very small amount of heat. I have diagnoised many piston slap concerns in differnent engines and it does seam to be the case in my car. Carbon build up caused this type of condition in 2000 and up Northstar Cadillacs, it was also a factor in the cold knock in the 3.0 Probe during the mid 90's. I will be inspecting my combustion cambers via bore-o-scope for this issue. It was present in Northstars as low as 4000 miles due to combustion temp being lowered with the revised cyl head in 2000. I have checked my plugs and found no evidence of detonation as noted by some unhappy Cobra owners bitchin on another site. I do not have the timing adjuster as of yet. If you get a chance set it back to 6 or 8 degrees then drive it cold and see if it changes. I will indicate my findings from the internal inspection possibly nest week when I get access to the needed scope.
The noise just doesn't seam to be a piston noise but I may be wrong. At 22000 not very easy miles with no change at all the piston issue doesn't seam to worry me. 95 Cobra R's had a detonation rattle almost identical to this. I personnally experienced it in the two cars I drove new at the dealership. It was a processor calibration issue that would have required Ford to get a recertification. Less than 300 cars didn't justify the expense. Never got fixed to my knowledge. Would be interested if any you with Superchargers out there have noticed a change with boost?


<font size=-1>[ This Message was edited by: cobrar1993 on 2002-02-11 19:50 ]</font>

 

[skammer1]

Greetings fellow Mustang Owners: I am new to the bullit forum and caught this thread at stangnet.com I have some dyno plots of our 01 GT that detonates like you speak of when warm or cold...regardless of octane fuel. If someone could email me a place to put these dyno plots, I have the .gif files ready to load. [email protected]

 

[anippy]

I hope ya'll don't mind me posting, as I have just a plain ole '01 GT.

I've been having a spark knock/detonation problem practically since the day I brought the car home in September. It is most pronounced when using 87 octane fuel (which the owner's manual recommends). Ford dealer said "Try 89 octane." The problem hasn't cleared up.

So this past weekend we put it on a dyno. Knocked like hell through the entire range with 87 and 89 and at the top with 93.

As I am posting this, the dealer has the repair foreman and Ford's engineering department involved. They are asking for more dyno printouts showing "normal" graphs versus my EKG-like dyno graph. They all seem to be completely stumped.

The garage also measured the timing during the runs. That fluxuated really bad too, from 21 degrees all the way down to 7.

Gas mileage has been atrocious, about 13-14 in the city, barely 20 on the highway (with 89 octane).

We'll see what Ford has to say about it.

 

[DrivingSimulators]

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2002-02-18 11:31, anippy wrote:
I hope ya'll don't mind me posting, as I have just a plain ole '01 GT.

I've been having a spark knock/detonation problem practically since the day I brought the car home in September. It is most pronounced when using 87 octane fuel (which the owner's manual recommends). Ford dealer said "Try 89 octane." The problem hasn't cleared up.

So this past weekend we put it on a dyno. Knocked like hell through the entire range with 87 and 89 and at the top with 93.

As I am posting this, the dealer has the repair foreman and Ford's engineering department involved. They are asking for more dyno printouts showing "normal" graphs versus my EKG-like dyno graph. They all seem to be completely stumped.

The garage also measured the timing during the runs. That fluxuated really bad too, from 21 degrees all the way down to 7.

Gas mileage has been atrocious, about 13-14 in the city, barely 20 on the highway (with 89 octane).

We'll see what Ford has to say about it.
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

As you've found, octane is not the answer. My current guess is that there is something hosed between the sensors and the computer, or a defective computer. The system as a whole is not stable: the engine does not pull smoothly (dyno plots would be interesting).

So, the question is, what sensor(s) could be bad:

1. Mass Airflow Sensor (MAF)
2. Throttle position sensor
3. Engine (crank? cam?) position
4. Exhaust (O2, etc., if the readings are used for engine control)
5. Temperature sensor(s)
6. A short somewhere causing the computer to get constant, spurious interrupts which effectively introduces lag in control response.
7. Any other sensor / computer control path that introduces invalid sensor readings or causes invalid output responses.
8. Any pure mechanical component that could possibly affect the system.

What's the fast and dumb way to debug this? Find a similar vehicle that does not exhibit these problems and start swapping parts: computer, MAF, throttle position sensor, any other possible sensor.

Why not use new parts? Because we need to test with parts we know work correctly. New parts could also be defective.

My car exhibits behavior very similar to yours. Thank you very much for your post. The more information we can compile, the sooner we can figure this thing out.

One more thing: it's possible that the detonation issue and rattle sound are unrelated (two different problems). My primary concern at the moment is the preignition+detonation issue.


<font size=-1>[ This Message was edited by: DrivingSimulators on 2002-02-18 12:29 ]</font>

 

[skammer1]

I have Dyno Plots that show clear detonation through the rev range. Octane doesn't help the problem...I have dyno plots! [email protected] if you need graphs...Mines at the dealer now, and they are trying to arrange for some type of "Black Box" to be installed to collect data. The other gentlemans symptoms are identical to mine.

_________________
2001 Mustang GT Min Grey

<font size=-1>[ This Message was edited by: skammer1 on 2002-02-18 15:02 ]</font>

 

[DrivingSimulators]

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2002-02-18 14:57, skammer1 wrote:
I have Dyno Plots that show clear detonation through the rev range. Octane doesn't help the problem...I have dyno plots! [email protected] if you need graphs...Mines at the dealer now, and they are trying to arrange for some type of "Black Box" to be installed to collect data. The other gentlemans symptoms are identical to mine.

_________________
2001 Mustang GT Min Grey

<font size=-1>[ This Message was edited by: skammer1 on 2002-02-18 15:02 ]</font>
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

Sean was kind enough to email me GIF files of his dyno runs. I've converted one to a smaller JPG, posted below.

This is exactly what my SOTP meter registers: the engine does not pull smoothly (along with preignition+detonation).

<td align="CENTER"

</td>