Car Idles Fine But exhaust sounds like Lawnmower

[viperjames]

i was driving down the highway in 4th WOT when i hear a big woosh then i looked in the reveiw mirror to check for BHG but nothing no color in the exhaust at all all guages were right. i changed the plugs (plugs were crisp brown) and still the exhaust sounds like a lawnmower?

mods are DDP, IC pipes

 

[dbsupra90]

blow off an ic pipe?
aside from the sound, how does it drive?

 

[viperjames]

i have a 20 meg vid but i dont know where to post

 

[viperjames]

http://media.putfile.com/Exhaust-Lawn-Mower

 

[IJ.]

Rod Knock

 

[kikdurazz]

Sounds like rod knock to me, sorry joe listened to it three times and that is exactly what it sounds like.

 

[viperjames]

when i am in gear and slow down it goes away it doesnt sound like metal on metal
just bumps in the exhaust

 

[IJ.]

does the sound change with the rpm?

 

[viperjames]

no it doesnt

 

[IJ.]

does the noise get faster when you rev it ?

 

[jimi87-t]

does the noise get faster when you rev it ?

It sounds like it to me, at the end of the vid he revs it a little and it speeds up with the rpms

 

[dbsupra90]

holy crap thats bad. not at all what i thought you were talking about.
pull the plug wires at the coil pack one at a time and see if it goes away w/ a certain cyl. be careful, if you hold it too close to ground or the coil pack it will arc. after this, let it cool down and pull the plugs and inspect them as well. look for signs of detonation such as chipped insulators or melted grounds. also look to see if there is any sign of physical damage to the pistons.

 

[viperjames]

it sounds like it happends after the trubo
like the turbo is knocking

 

[johnathan1]

knocking turbo?? wtf?? lol

How's your oil level...?

 

[viperjames]

is there anyway that the fins on the hotside are off or something is bouncing in the turbo.. the oil was full when it happend and still full so im not sure what happend i dont get power anymore either.. if i floor it in second i cant even break the tires loose in the rain not making boost either.. if it was knock then wouldnt the car keep the power but knock.. it basically sounds like a fatboy harley when im moving

 

[1TuffSupra]

it sounds like it happends after the trubo
like the turbo is knocking

I was going to say the same thing. My motor with knock sounded like yours, but you could definitely tell the knock was coming from the motor. Yours seems to be coming from near the exhaust under the car. Plus if it is in fact rod knock it wouldnt have been a sudden thing as you described, but much more gradual. Have you checked to see if you have any exhaust leaks anywhere?

 

[mkIIIman089]

Sounds like rod knock to me, and it definitly does change with RPM.

I'm going to say its impossible for the turbo to make a noise like that, and that its not the turbo, lol.

What kind of oil and how old was it? That motor I must say looked pretty sickly to begin with noticing your no fan shroud on stock rad and the oil all over the top of the motor...

I will go out on a limb here and say you might have done something bizarre to your clutch and it just nuked something thats hitting something else, but other then that; rod knock.

 

[hottscennessey]

rod knock

 

[viperjames]

im almost sure its not knock because the engine runs smooth as soon as the exhaust leaves the motor it sounds like a bike . im going to take the turbo off and inspect it.. if it was rod knock i would still be able to boost i can not boost right now at all. i have had rod knock before and it sounds nothing like this the video makes the sound more extreme

 

[jimi87-t]

Simple, pull the turbo and check it out. I would advise not driving it the way it is, so start pulling stuff off.