What is this sound?

[vertigasen]

Alright, I was on the way to work today and everything was good. I was driving on I-95 doing about 60 behind a grandma in a minivan. She finally moved, and instead of downshifting to 4th, I stayed in 5th and gave about half throttle. When I hit right about half throttle, I got a weird sound, almost a rattling sound coming from the engine. I backed off the throttle and tried again, the same thing. Just to make sure everything was ok, I downshifted to 4th when to half throttle, and nothing, I floored it, nothing, still sounded fine. When I slowed down to about 60, I tried it again in 5th, and the same thing. I have never heard this before, and it didnt sound good. Anyone ever heard this? I will try to get a recording of it and stick it up here tomorrow.

 

[twothousandgt]

I have the same thing if its the same sound, like a ringing sound? for me it happens any gear, at exactly 61mph. and its oh so annoying.

 

[sunburstgold]

Mine does that too and its a mystery to me also.
I've come to the conclusion that its the cai though, i dont know if your intake is stock but it may be that whistling a little bit... maybe...

 

[vertigasen]

My old cai used to whistle, but since I got a MAC straightshot, I dont have any whistling issues. It is definately a rattling sound with a slight ring to it. I have heard this before, but this was in my older pickup and it was the catalytic converter going out. I would use this as a viable excuse, but I have gutted cats, so that rules that out.

Any help would be greatly appreciated.

 

[Yellow 281]

This sounds like tip-in detonation. My car does that too and it drives my crazy.

Can anyone else confirm this?

 

[four six]

yup yup me too

I don't remember if it happened before the CAI

 

[mustangkid05]

yes me too.....i think someone told me i was lugging the engine?

 

[Jsun3701]

Sounds like an exhaust leak.

 

[vertigasen]

Sounds like an exhaust leak.

I thought of that too, but why would I only notice it in 5th gear @ 1800 rpms @ 60 mph on the highway? I figure I would notice an exhaust leak at WOT in second gear more than 1/2 thottle in 5th. I am going to check this weekend when I seafoam it. If there is an exhaust leak, bet I find it with that.

 

[BurningRubber]

Sounds like pinging. An exhaust leak would be heard under load in any gear, including flooring it in 4th.

 

[steveb24]

i swear at that speed and gear i hear my rear window vibrationg somehow.. it sounds like a rattle/ping too. trust me i know, i just drove freakin 700 miles in the past 24 hours. pittsburg and back