Rattle sound on cold start

[SpectorV]

After my car has sat for a long time (cooled off) or early in the morning when I start it I noticed a rattle sound. It could be my clutch, it seems to be at a given rpm. After a little bit its gone and doesnt come back until a cold start again.

Could there be anything that once warm it might not make a noise, clutch related or something else I can look into?

I had a friend listen with the hood open one time and he couldnt hear it, but when we turned it off and tried again with him back by me at the door he could hear it.

its just a rattle like sound

 

[fink46]

I have what sounds like the same rattle your describing. It would do it when cold out 50 degrees and lower. It would rattle for minute or so at idle, then start to fade but would still be there if you blip the throttle untill fully warm, then it would not be noticable.

I had an issue this summer with a rattle noise on deacceleration turned out to be a bad cat. I'm thinking the cold rattle is most likely piston slap.

 

[chitowncobra]

After my car has sat for a long time (cooled off) or early in the morning when I start it I noticed a rattle sound. It could be my clutch, it seems to be at a given rpm. After a little bit its gone and doesnt come back until a cold start again.

Could there be anything that once warm it might not make a noise, clutch related or something else I can look into?

I had a friend listen with the hood open one time and he couldnt hear it, but when we turned it off and tried again with him back by me at the door he could hear it.

its just a rattle like sound

hey its normal for our cars 03/04 cobras its piston slap, cold it rattles up a storm!!! when hot goes away,normal thing w/ forged pistons!!!:-D:-D:-D

 

[99riocobra]

piston slap, lash adjusters not filling with oil all the way, spark plug loose(happened to me)

 

[04cobrawhine]

you still have cats? good chance one of them is falling/fell appart.

 

[CobraBoatDan]

I never had a cold rattle with my stock pistons in my cobra. I know some forged pistons will do it though, my old mazda had forged pistons and it would do it. That sounds to me what you are describing though.

 

[SpectorV]

I have had the car for over 4 years and ive never heard the noise before so I dont think its piston slap.

I will check the plugs to double check them as you never know. It could be the cats I guess didnt think about it. The car has 60k on it, 2k pullied or there about~.

Any other thing I can do to check on the cats being bad? Usually the noise is more like a clutch type noise this was the first time it was more like a rattle, it was 70 degrees outside when it did it as well.

 

[timspony]

My DSG has had this same noise for the 5 years that I've owned...and only on Cold start-ups...after car is warm (5-7 min.), no noise!! ...I called SVT and they told me it was piston slap & not to worry about it! ...So far 5 years later (and many run's at the Drag Strip), NO Problems!!

(Knock on wood!!)

 

[fink46]

Does it sound anything like this?[nomedia="http://www.youtube.com/watch?v=KWuKRazW3XM"]YouTube - 2003 cobra engine noise cold[/nomedia] Turned out to be a bad cat on drivers side, still had original h pipe with 51000 miles on it. The mechanic told me as soon as you pulley these cars it takes a toll on the stock cats with the extra airflow and heat.

 

[GoatSlayer]

Had the same problem with my car, turned out to be a bad rod bearing.

 

[04cobrawhine]

crawl underneath your car with it cold and hit the cats with a dead blow hammer. see if they rattle.

 

[timspony]

Had the same problem with my car, turned out to be a bad rod bearing.

Wouldn't the noise be there all the time with a rod bearing? :shrug:

 

[stang03]

Double post FAIL!

 

[stang03]

I dont own a cobra, but I have the same problem on my S197....rattles at startup then goes away...I have been under my car multiple times checking the exhaust for loose bolts or rubbing the frame, even tapped around with a rubber mallet, and came up with nothing....dont think i tackled the cats though...may have to do that, its annoying as heck

 

[timspony]

Not the Cats in my case...I've dad the noise with the Stock H-pipe, Bassani Catted X & now with the Bassani Straight pipes!

 

[eric p]

LOL. I had piston slap on my 2001CR250 dirtbike. Its NOT normal. It indicates wear.

You did not tell us where the noise is coming from! How loud? Is there anything you can do during the time of the noise that makes it diminish?.....

Your description of a rattle could be MANY things. I have an "out-side-of-the-box" thought..... let your car sit over night. In the morning pop the hood. Start your car. Once the car is started and you hear the "rattle" locate the PCV from your driver side valve cover and pull it completely out of place. If the "rattle" disappears, then its probably a rattling PCV valve.

Its a dumb thought, however, in my experience those dumb ideas can be the solution.

let us know!

 

[SpectorV]

Does it sound anything like this?YouTube - 2003 cobra engine noise cold Turned out to be a bad cat on drivers side, still had original h pipe with 51000 miles on it. The mechanic told me as soon as you pulley these cars it takes a toll on the stock cats with the extra airflow and heat.

It kinda sound like that in a way, it is a hard noise to describe, sorry for not being able to be more descriptive. It seems to come from the back of the engine. My friend stood in front with the hood open and could hear nothing, but from the back he could also hear it. The noise happed at a given rpm when cold, if it was idling low it wouldnt do it, a little rev and at the right rpm it would do a similar noise

LOL. I had piston slap on my 2001CR250 dirtbike. Its NOT normal. It indicates wear.

You did not tell us where the noise is coming from! How loud? Is there anything you can do during the time of the noise that makes it diminish?.....

Your description of a rattle could be MANY things. I have an "out-side-of-the-box" thought..... let your car sit over night. In the morning pop the hood. Start your car. Once the car is started and you hear the "rattle" locate the PCV from your driver side valve cover and pull it completely out of place. If the "rattle" disappears, then its probably a rattling PCV valve.

Its a dumb thought, however, in my experience those dumb ideas can be the solution.

let us know!

When the vehicle is cold and I start it as it idles back down I hear a rattle like noise. Only in the last couple of times has it been more of a rattle instead of just a semi clutch noise like a throwout bearing would make as as it started to go bad. Its not always a rattle as the vid above sounds it has just been more of a rubbing noise if that makes since.

It goes away really quick, only there for about the first few seconds. When driving while its cold it seems to make a very quick semi detonation like sound (higher pitched and higher frequency) right as I start to push in the gas after a shift at low rpms. It goes away in under a second. After the car is warm it wont do this either.

 

[*P*Grass]

my 2cents; sounds like hole/leak in the exhaust needs to be tightened up?


i had the same thing car runs fine when car is cold i hear a rattle but when it warms up rattle goes away. turns out the rattle was caused by my RAI touching/rattling on the inside of the finder. readjusted RAI and it fixed it.