FFFFF TTT!!!! Sound

[Guy]

I know the subject sounds funny, but that's a sound my '05 has started making when it's cold (when the car is cold, not the weather, it's about 100 around here these days!)...

I'll start up the car and it'll do its usual angry/rough idle viper thing and occasionally it will go FFFFFTT then idle a few more seconds and FFFFFTT again.. I wish I could have recorded the noise, but unfortunately, it stopped doing it the last two times I tried to record it.

It stops doing it once driving, even when idling at a set of lights.

It's a weird sound and almost sounds like a backfire after the FFFFTT.

Any ideas? Fuel injector occasionally stuck open? Exhaust leak?

 

[Venomiss]

It's not a fan perhaps?

Have you looked with the hood open when car is started cold?

 

[Guy]

It's not a fan perhaps?

Have you looked with the hood open when car is started cold?

I haven't, and will definitely check it out, thanks for the idea!

It does seem to come out from the exhaust "area". Almost like something shoots through the pipes, but I'm not exactly sure it shoots out of the tip (if that makes sense). That's why I suspected a leak.

 

[Tom F&L GoR]

Some mufflers have a small hole to allow water condensation to escape. Is there a small puddle under the car ?

 

[GR8_ASP]

If your front O2 sensor is not heating up properly, providing a false O2 reading an extreme lean condition may result causing a wheezing, almost chirp like sound from the exhaust of one bank. I experienced this about 1 to 2 weeks before setting the MIL for O2 heater.

 

[2000_Black_RT10]

Could be in the valvetrain, spring, valve seat or... a leak down test may help to (in)validate this theory..

 

[CPPRHD265]

Guy, does your car go above 4,500 RPM without issues?

My saga below:

Mine was making strange puffing sounds when it was cold, I thought the drivers side manifold had a leak. Then, the car started acting wierd in the upper RPM ranges, almost like a rev limiter kicked in at 4,500 RPM.

I took it in to the dealer. After a couple days with the car, the mother ship authorized a full rebuild when the tech discovered frozen rings on one of the drivers sides pistons. Seems it was blowing by the piston on that cylinder, and probably a couple others.

It took about a month, but the rebuild was fantastic. It put down 475/500 to the tires after the 1000 mile break-in, bone stock right down to the air filters.

How did it happen? Well, the best thing we could figure... The car was two years old when I got it with about 5200 miles on it. We guess the first owner was in the habbit of starting it up once a week in the garage, but never letting it get warmed up fully. This probably produced the massive carbon fouling. So much so, that the cats started to foul... as well as the rings.

 

[Guy]

Thanks for the replies guys. Looks like I'll get an OBDII scanner and see the readings when cold.

Guy, does your car go above 4,500 RPM without issues?

It does... But, wow, am now definitely a little more worried!

On the other hand, I always wanted an engine capable of 2000hp

Thanks guys. I'll try to update any info on here if I find out sooner than later what's going on!