2011 Mustang 5.0L Knocking On Cold Start/Drive - Page 2 - Ford Mustang Forum
Reply
 
LinkBack Thread Tools
Banned
 
shadowstang03gt's Avatar
 
Joined: Aug 2010
Location: lehigh valley
Posts: 231
 
Quote:
Originally Posted by Double-J View Post
Until it warms up, I have that 'piston slap' type noise between 2-3.5k rpms as well. I just thought that was normal, is it not?

it probably is normal noise for the motor. but people make big deals about nothing and like to cry.

shadowstang03gt is offline  
Sponsored Links
Advertisement
 
GT Member
 
MustangFaith72's Avatar
 
Joined: Apr 2010
Location: NoVA
Posts: 1,141
 
Quote:
Originally Posted by shadowstang03gt View Post
it probably is normal noise for the motor. but people make big deals about nothing and like to cry.
And then losers, so insecure that someone could say something bad about their car, write posts criticizing others' concerns.

MustangFaith72 is offline  
Rookie
5.0L Member
S197 Member
 
yllwfstbck's Avatar
 
Joined: Jan 2011
Location: on the streets
Posts: 22
 
Your a idiot.for something to make that amount of noise.there something wrong.my 1970 solid cam in my other Stang don't even have that much noise.when you get a clue you can join in the conversation.
yllwfstbck is offline  
 
post #19 of 323 (permalink) Old 01-10-2011 Thread Starter
Apprentice
 
SCCA2011GT's Avatar
 
Joined: Dec 2010
Location: Baton Rouge
Posts: 133
 
Quote:
Originally Posted by shadowstang03gt View Post
it probably is normal noise for the motor. but people make big deals about nothing and like to cry.

I have to disagree with you, respectively of course. While it is normal for a new engine to potentially make different noise then we are all accustomed too, this noise is NOT normal at all. When it sounds like the motor will come apart in a few thousand miles, I take a bit of caution. Especially for the fact that if in fact it broke shortly after the warranty was up due to this issue, I would expect Ford to cover it. More than likely, if this is a big issue, it will cause its damage well before 36K miles. But... you cant be too cautious. Cautious usually costs less than reckless.
SCCA2011GT is offline  
post #20 of 323 (permalink) Old 01-10-2011 Thread Starter
Apprentice
 
SCCA2011GT's Avatar
 
Joined: Dec 2010
Location: Baton Rouge
Posts: 133
 
UPDATE:
The car spent the weekend at the dealership and I got a call this morning. They went through and measured clearances and checked for spongy lifters (I am not sure how). They loosened the cams and re-torqued them with the correct specs. Upon putting the valve covers back on, the tech accidentally pinched one the new gaskets causing the seal to leak a little, so he didn't make it out the parking lot. They ordered another new gasket and it will be in and installed tomorrow. I am about to go down there and take a look at the engine for myself because I noticed some things in the pictures that peaked my curiosity. Tomorrow, I will find out if the noise is gone or if I have to do more troubleshooting. More to come.
SCCA2011GT is offline  
GT Member
 
MustangFaith72's Avatar
 
Joined: Apr 2010
Location: NoVA
Posts: 1,141
 
LOL, they tightened the cam caps on mine trying to fix an idle tick. When they put it back together, they also broke a couple things on mine. Caused a few days delay in getting the car back (and didn't fix the tick).
MustangFaith72 is offline  
post #22 of 323 (permalink) Old 01-10-2011 Thread Starter
Apprentice
 
SCCA2011GT's Avatar
 
Joined: Dec 2010
Location: Baton Rouge
Posts: 133
 
Well I am not optimistic that the noise will be gone. I went by the dealer and shot some pictures of the top of the head, cam phasers, chains, etc. My theories are this:

1. The oil pressure in the lifters is a little lax at cold temps causing the rockers to be rather noisy. As the oil warms up and flows a little better, then the lifters (including the one that tensions the chain between the two cams in the head) pump up a little tighter and remove slack.
2. The previous OHC engines had urethane of some sort on the main chain guides. This engine does not appear too from what I can see looking into the timing cover. It appears that the chain-guide contact is metal to metal. So when the engine is cold and there is a little more slack in the parts, the noise is actually the chains banging against the guides.
3. The design of the rocker arms is a little different on this engine than my previous 4.6L. The contact patch of the rocker arms to the valve stem was a U shape which in essence centered or "locked" the end the rocker in place on the valve stem. On this 5.0, the end of the rocker arm is a flat piece of metal that sits on the valve stem tip. The noise is possibly the rocker arm rattling against the valve stem until one of the previous occurs (engine warms to take up slack).

Whatever the case is, it does not explain why only a handful of cars thus far (that we know of) have the problem. It definitely sounds like slack in the valve train..... just which part?
SCCA2011GT is offline  
GT Member
 
MustangFaith72's Avatar
 
Joined: Apr 2010
Location: NoVA
Posts: 1,141
 
If we're talking about the same noise (which is always tough to decipher over the internet), then at least one person has claimed that Ford is calling it "piston noise." As with some other frustrating problems on this car, they claim the problem to be a "normal characteristic."

The quote: "Pistons are designed to fit the cylinder bore with the engine at operating temperature. Due to different thickness and expansion rates at various points on the piston, the piston will have different cylinder wall to piston clearance cold to hot. Due to the piston shape some cold piston noise is considered a normal engine characteristic. The noise should be considered a characteristic of the high performace engine design" (spelling corrected).

The writer claims that this was sent to his dealer from Ford. Of course, no way to confirm it. See this thread:

Really Disappointed with Ford - SVTPerformance
MustangFaith72 is offline  
Rookie
5.0L Member
S197 Member
 
yllwfstbck's Avatar
 
Joined: Jan 2011
Location: on the streets
Posts: 22
 
its funny if ford did say that.i read a article from ford before 2011s came out.it stated they used hyperutectic so the could get the tolerance tighter in the bore to prevent piston noise.they wanted to use forged but they went hypers because the hypers dont expand and contrat as much as a forged pistons.
yllwfstbck is offline  
post #25 of 323 (permalink) Old 01-11-2011 Thread Starter
Apprentice
 
SCCA2011GT's Avatar
 
Joined: Dec 2010
Location: Baton Rouge
Posts: 133
 
Also... the variable in this whole thing remains the fact that if were hardware related, by that I mean the type of hardware or material the hardware was made of, then every engine should exhibit the same noises to some degree. They are all made of the same parts, assembled in the same fashion. It would stand to reason that more people would notice the noises. So far that does not seem to be the case though.
SCCA2011GT is offline  
Rookie
 
lodom's Avatar
 
Joined: Nov 2010
Location: Bartlett
Posts: 12
 
I agree to a point, but you also need to consider manufacturing tolerances from the suppliers or in the machining work. If you measured all 8 pistons, you'd likely see a very small difference in a few that could explain why one motor is quieter than another, or even variences in the cylinder bore, etc. GM's LS1 engine had a history of piston slap on cold start up and they started putting a coating on the piston skirt in 2002 to reduce the noise. Since this appears to be a new problem for Ford, maybe they'll come up with a similar solution for the Coyote motor.
lodom is offline  
GT Member
 
MustangFaith72's Avatar
 
Joined: Apr 2010
Location: NoVA
Posts: 1,141
 
The most realistic solution might be Roush axle-backs
MustangFaith72 is offline  
post #28 of 323 (permalink) Old 01-12-2011 Thread Starter
Apprentice
 
SCCA2011GT's Avatar
 
Joined: Dec 2010
Location: Baton Rouge
Posts: 133
 
Quote:
Originally Posted by cidsamuth View Post
The most realistic solution might be Roush axle-backs
Thats definitely one fix, although I think in my case, I may still hear it over the exhaust.
SCCA2011GT is offline  
Rookie
5.0L Member
S197 Member
 
yllwfstbck's Avatar
 
Joined: Jan 2011
Location: on the streets
Posts: 22
 
well ford called and said there is timing chain tensioner failure.the parts are on order.we will see if they are correct.ill keep u posted on the final outcome afterthey finish it
yllwfstbck is offline  
post #30 of 323 (permalink) Old 01-12-2011 Thread Starter
Apprentice
 
SCCA2011GT's Avatar
 
Joined: Dec 2010
Location: Baton Rouge
Posts: 133
 
Quote:
Originally Posted by yllwfstbck View Post
well ford called and said there is timing chain tensioner failure.the parts are on order.we will see if they are correct.ill keep u posted on the final outcome afterthey finish it

Refresh my memory, you have the "tick", the piston "slap", or the "knock" on cold start?

SCCA2011GT is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Mustang Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a VALID email address for yourself, otherwise you will not receive the necessary confirmation email needed to confirm, validate and activate your new AFM member account.

Failure to provide a VALID email address, will result in the cancellation of your new AFM member account registration.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may 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 Off
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome
 


Search Engine Friendly URLs by vBSEO 3.6.1