Detonation or Not Detonation? - Mustang Evolution

Go Back   Mustang Evolution > Shelby | ROUSH | Boss | Saleen | SVT || Tech and Talk > SVT Mustang



Reply
 
Thread Tools Search this Thread
Please support our sponsors and let them know you heard about them here!
Old 03-14-2011, 08:28 AM   #1
Moderator Emeritus
Legacy
Regular
 
SpectorV's Avatar
 
Join Date: May 2003
Region: Alabama
Posts: 26,049
Send a message via AIM to SpectorV
Detonation or Not Detonation?

... that is the question...

I hear a rattle at 1400-1500 rpms gets harder to hear (I think) when the car is warmer.

sounds kinda like detonation as I have heard my car detonate, I heard it detonate over the weekend (gas....) and this is almost like it but it sounds "lower" on the motor (hear it bouncing off the ground more so) and is a bit higher pitched than the normal detonation.

I took it down from 23 deg timing to 21 deg with a different tune I have and same noise same time same amt of noise for the issue I am talking about. My normal detonation went away but the noise I mentioned above did not change.

I am thinking its not detonation, but... not sure how to rule it out other than leave it at 21 degrees and put in some race gas to ensure I have enough octane for the timing level.

It happens under normal acceleration. On WOT I hear NOTHING all seems fine.

Other thoughts are a cat going bad or something loose rattling, but I see nothing loose.

Any tips/tricks ideas etc? I want this noise at least figured out.

Thanks!
__________________
2003 Cobra Vert (Redfire) #3938 of 5082 @ 05/27/2003
472rwhp/493rwtq -Modification List - Dyno Sheet
2012 Mustang 3.7L M6 (Kona Blue)
2011 Ford Edge Sport (Red Metallic)
SpectorV is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 03-14-2011, 12:57 PM   #2
Road Trip!
 
Join Date: Dec 2010
Region: Louisiana
Posts: 1,635
Could be exhaust leaks. They can sound that way sometimes. Usually more when cold but worth a shot.
Alscobra is offline   Reply With Quote
Old 03-14-2011, 03:20 PM   #3
Moderator Emeritus
Legacy
Regular
 
SpectorV's Avatar
 
Join Date: May 2003
Region: Alabama
Posts: 26,049
Send a message via AIM to SpectorV
Re: Detonation or Not Detonation?

yea it wont do it while sitting still (that ive been able to make happen) so its hard to figure out....if it was exhaust it would do it sitting I would think but I cant simulate load~
__________________
2003 Cobra Vert (Redfire) #3938 of 5082 @ 05/27/2003
472rwhp/493rwtq -Modification List - Dyno Sheet
2012 Mustang 3.7L M6 (Kona Blue)
2011 Ford Edge Sport (Red Metallic)
SpectorV is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 03-14-2011, 03:25 PM   #4
Road Trip!
 
Join Date: Dec 2010
Region: Louisiana
Posts: 1,635
Quote:
Originally Posted by SpectorV
yea it wont do it while sitting still (that ive been able to make happen) so its hard to figure out....if it was exhaust it would do it sitting I would think but I cant simulate load~
That sucks man. You may have to diag that on a dyno.
Alscobra is offline   Reply With Quote
Old 03-14-2011, 03:46 PM   #5
Road Trip!
 
Join Date: Dec 2010
Region: Canada
Posts: 2,203
I hope it's just a bad tank of gas.

Built 2 Last TTT
Everett is offline   Reply With Quote
Old 03-14-2011, 05:24 PM   #6
Legacy Member
Legacy
 
lowflyn's Avatar
 
Join Date: Aug 2003
Region: Mississippi
Posts: 19,890
Send a message via AIM to lowflyn
Re: Detonation or Not Detonation?

Quote:
Originally Posted by SpectorV View Post
yea it wont do it while sitting still (that ive been able to make happen) so its hard to figure out....if it was exhaust it would do it sitting I would think but I cant simulate load~
The H-pipe on tiff's car won't exhibit ticking (from a leak) until you actually get it under load. Doesn't really do anything at idle or with a rev.

If you've ruled out detonation then it's got to be something else. What have you done differently?
__________________
"I'm not driving too fast...just flying too low"
Mine:
-03 SB Cobra vert- 2552 of 5082 Born 02/25/03
Our's:
90 7up vert - new project-07 DSG Focus -DD
335
lowflyn is offline   Reply With Quote
Old 03-14-2011, 05:35 PM   #7
Registered Member
Regular
 
SaleenFiend's Avatar
 
Join Date: Jul 2008
Location: Louisiana
Region: Louisiana
Posts: 2,318
Re: Detonation or Not Detonation?

Hmm.. that's weird. It seems like it would almost be a suspension component or some type of heat shield (or similar peice) if it's only happening when driving at that RPM.

Hit your cats with a Rubber Mallet and listen for anything odd-although, I doubt those are the problem.
SaleenFiend is offline   Reply With Quote
Old 04-18-2011, 10:00 AM   #8
Registered Member
Regular
 
Timm04's Avatar
 
Join Date: Apr 2011
Region: Minnesota
Posts: 540
That's weird the same thing happening to my car did you ever figure out what it was?
Timm04 is offline   Reply With Quote
Old 04-29-2011, 11:10 AM   #9
Registered Member
Regular
 
mz98snake's Avatar
 
Join Date: Mar 2011
Region: Texas
Posts: 91
Could also be piston slap.
mz98snake is offline   Reply With Quote
Old 04-29-2011, 03:37 PM   #10
Moderator Emeritus
Legacy
Regular
 
SpectorV's Avatar
 
Join Date: May 2003
Region: Alabama
Posts: 26,049
Send a message via AIM to SpectorV
Re: Detonation or Not Detonation?

Quote:
Originally Posted by lowflyn View Post
The H-pipe on tiff's car won't exhibit ticking (from a leak) until you actually get it under load. Doesn't really do anything at idle or with a rev.

If you've ruled out detonation then it's got to be something else. What have you done differently?
It only does it where I can hear it about 1500rpms under normal acceleration, but It does it other times (steady at given levels doesnt go away and come back) you just have to drive by a wall or something to hear it. I had my wife drive it home a while back and I heard it from behind the car easily when she drove off. Ive not changed anything in the last bit. I need to try tapping the cats with something rubber to see if I hear anything rattling around.

Quote:
Originally Posted by SaleenFiend View Post
Hmm.. that's weird. It seems like it would almost be a suspension component or some type of heat shield (or similar peice) if it's only happening when driving at that RPM.

Hit your cats with a Rubber Mallet and listen for anything odd-although, I doubt those are the problem.
Ive not ruled this out, I want to get under it tomorrow and see if I notice anything obvious and tighten up the exhaust just to see if it kinda helps it etc to clue me into what it is.

Quote:
Originally Posted by mz98snake View Post
Could also be piston slap.
It could be, but it does it even when warm just not as bad, also its not ever done this in 5 years so I dont think thats it or hope its not lol


Sorry for the delay in reply, didnt see the thread had been updated.
__________________
2003 Cobra Vert (Redfire) #3938 of 5082 @ 05/27/2003
472rwhp/493rwtq -Modification List - Dyno Sheet
2012 Mustang 3.7L M6 (Kona Blue)
2011 Ford Edge Sport (Red Metallic)
SpectorV is offline   Reply With Quote
Old 04-29-2011, 05:18 PM   #11
Registered Member
Regular
 
mz98snake's Avatar
 
Join Date: Mar 2011
Region: Texas
Posts: 91
Mine does the same thing. Even when hot. Less when hot. Sounds exactly like piston slap.
mz98snake is offline   Reply With Quote
Old 04-30-2011, 01:59 PM   #12
Registered Member
Regular
 
Pureoctane2001's Avatar
 
Join Date: Feb 2011
Region: Indiana
Posts: 71
Well I had a very similar occurance with my 01. Heard a rattling noise at higher rpm about where you would shift usually. Thought it was catlitic converters at first but soon after ruled out exhaust. After that I replace the throught bearing and clutch and flywheel insert.... No luck again well upon further inspection of the car by my mechanic buddy found out the motor had been out and there was a supercharger oil sending unit mounted on the underside of the block. The rattling was due to too much gas in the cylinders being pushed into the oil. (had upgraded fuel system with no return line) this ate one or more beRings where the rods mount to the crankshaft. It's still running strong but I figured I'd give ya an idea of what I had happen Good luck
Pureoctane2001 is offline   Reply With Quote
Old 04-30-2011, 02:03 PM   #13
Registered Member
Regular
 
Pureoctane2001's Avatar
 
Join Date: Feb 2011
Region: Indiana
Posts: 71
And also it gets quiet when the motor warms up to operating temperature. Metal expands when hot. This would prob be a worse case scenareo
Pureoctane2001 is offline   Reply With Quote
Old 05-02-2011, 09:14 AM   #14
Moderator Emeritus
Legacy
Regular
 
SpectorV's Avatar
 
Join Date: May 2003
Region: Alabama
Posts: 26,049
Send a message via AIM to SpectorV
Re: Detonation or Not Detonation?

i got under there and checked all the bolts, connections, etc, noticed a little water around one of the exhaust connections, bolts were good though. The last thing I decided to check was the oxygen sensors... one of very loose, turned by hand. I had them out when they checked my A/F a while back. Gonna drive it soon to see if that was the issue
__________________
2003 Cobra Vert (Redfire) #3938 of 5082 @ 05/27/2003
472rwhp/493rwtq -Modification List - Dyno Sheet
2012 Mustang 3.7L M6 (Kona Blue)
2011 Ford Edge Sport (Red Metallic)
SpectorV is offline   Reply With Quote
Old 05-02-2011, 10:41 AM   #15
Registered Member
Regular
 
mz98snake's Avatar
 
Join Date: Mar 2011
Region: Texas
Posts: 91
Hopefully man! I just ignore mine now. I ran it to redline racing a buddy, noise didn't get worse. It not rpm dependant in my case.
mz98snake is offline   Reply With Quote
Old 05-02-2011, 10:43 AM   #16
15.3 Second V8 Killer Yo
Legacy
Regular
 
PureVenom's Avatar
 
Join Date: Aug 2004
Region: Louisiana
Posts: 7,212
Send a message via AIM to PureVenom Send a message via MSN to PureVenom Send a message via Yahoo to PureVenom
Re: Detonation or Not Detonation?

Quote:
Originally Posted by SpectorV View Post
i got under there and checked all the bolts, connections, etc, noticed a little water around one of the exhaust connections, bolts were good though. The last thing I decided to check was the oxygen sensors... one of very loose, turned by hand. I had them out when they checked my A/F a while back. Gonna drive it soon to see if that was the issue
I had the same thing happen last year and it drove me nuts...but it didn't sound anything like detonation to me...sounded like something rattling....and would get worse in the higher RPMs. I thought it was clutch related till I saw the O2 sensor.
__________________
"When I know more, I'll be forthcoming. Or I won't be forthcoming, and I'll be honestly deceptive." - Les Miles
PureVenom is offline   Reply With Quote
Old 05-02-2011, 11:18 AM   #17
Legacy Member
Legacy
 
lowflyn's Avatar
 
Join Date: Aug 2003
Region: Mississippi
Posts: 19,890
Send a message via AIM to lowflyn
Re: Detonation or Not Detonation?

Hm...gonna have to check tiff's o2 sensors...didn't even think of that.
__________________
"I'm not driving too fast...just flying too low"
Mine:
-03 SB Cobra vert- 2552 of 5082 Born 02/25/03
Our's:
90 7up vert - new project-07 DSG Focus -DD
335
lowflyn is offline   Reply With Quote
Old 05-02-2011, 12:40 PM   #18
Moderator Emeritus
Legacy
Regular
 
SpectorV's Avatar
 
Join Date: May 2003
Region: Alabama
Posts: 26,049
Send a message via AIM to SpectorV
Re: Detonation or Not Detonation?

yea hopefully that was it
__________________
2003 Cobra Vert (Redfire) #3938 of 5082 @ 05/27/2003
472rwhp/493rwtq -Modification List - Dyno Sheet
2012 Mustang 3.7L M6 (Kona Blue)
2011 Ford Edge Sport (Red Metallic)
SpectorV is offline   Reply With Quote
Reply

Lower Navigation
Go Back   Mustang Evolution > Shelby | ROUSH | Boss | Saleen | SVT || Tech and Talk > SVT Mustang

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


» Like Us On Facebook



01:57 PM


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0

MustangEvolution.com is in no way associated with or endorsed by Ford Motor Company.