I have a 2010 ss, on a cold start while its warming up, it makes an odd loud noise for a minute or two, then stops and you hear the periodic direct injection tick..what is the noise im hearing while warming up?

 

does it stop when the rev's drop below 1g?

It's probably just your cats warming up

 

What does it sound like? The engine makes a freaking racket in the hood. Hell it's easier for me to diagnose a noise in my diesel truck.

Its probably just part of the catalyst warmup cycle. Mine lasts for a minute or 2 at the most.

 

Ya kit just sounds crazy under the hood for the first 2 minutes, when it warms up.and the rpms drop it stops.

 

Does it do it even when you start it when warm?

 

he said in original on cold start

lol the greatest is in the winter time... it's like -30 c outside, and i'm in the garage.. and I start up my car first thing in the morning.. all you can hear in the garage.. BR BR BR BR BR BR BRRRRRRR BRBRBRBR

 

id have to agree with everyone else. mines sounds like a mad 50trim turbo sucking air till its revs die down

 

I am aware of that, I was curious if it was 100% only when cold, that's all.

Wouldn't the engine enrichen on cold starts? I wonder if the EGR valve is going crazy. I don't have an LNF, so I am just speculating.

 

You can give the gas a tap to make it go away, but better to just let it go through the warm-up cycle until you're actually ready to drive.

 

if it sounds like its sucking air like a banchy, that normal, its cat warmup mode, its dumping fuel and required air into the motor to heat up the cat quickly.

 

just realized says your byt tuned.. i think you can disable the warm up?

 

Yes, you can I hated the "cat warm" as we call it lol so I had it removed as we all do I'm sure

 

Yea there is really no need for cat warm up if you no longer have cats. But you motor will still want to warm up in a timely fashion. It may do it in very cold areas either way. I don't know, you see in southern california we don't have winters, it drizzles a little and it MIGHT hit 30 where I live a handfull of times a year.

 

yea it sounds normal, The LNFs im around do that and im sure my new car does it as well.

 

***** ^

 

nah took them down lol

 

I don't like you anymore

 

Once I get rid of the LSJ and the LNF is left ill put ***** back up...

 

The reason for the exhaust noise is the spark timing is delayed until after TDC so that the mixture is still burning when the exhaust valve opens. The burning in the exhaust manifold raises exhaust temps to help heat the cat up quicker. It also makes the turbo spool which is responsible for the increased sucking sound.

 

so HP tune has a way to get rid of this I thought only Vince could

If so I so want to get rid of it. it soo loud

 

Thanks for all the information guys!