NO. its not a rod knock. i believe its a exhaust leak, but all the gaskets\bolts are brand new and tighter then a lick. sound is VERY loud about 12 inches down from were the turbo and exhaust meet. aka right under the oil pan. I've taken a stethescope and listen, its coming from the exhaust, somewhere i believe. hangers are tight, downpipe bolts are tight, o2 housing bolts are tight, turbo to manifold are tight, manifold to head are tight, turbo mount that connects to block is tight, all o2 sensors are tight, sway bar\cross bar isn't hitting the downpipe, all the v-bands are tight, rear hangers are tight, rear of the exhaust isn't vibrating. please listen to the sound and give me an idea. this started happening after i boosted the 2ND time after installing my turbo and injectors.

http://www.youtube.com/watch?v=8Ptw5ngizO8

 

took it around the block, goes away when accelerating when i let off the gas it will do the noise even louder while driving.

 

If it's exhaust leaking a WB will read unusually lean at idle, like 18:1 and mild cruise would be normal. I would be cautious until you find out what it is just in case something is knocking.

 

have you changed your oil? ... same thing (sorta)happened to my cousin's sentra... it was metal shards bunched upped together and being tossed around by the oil pump... do you have a pressure gauge?


good luck man!

 

wb isn't reading anything abnormal, oil i JUST changed, but idled for over 2 hours, with no problems until boosting for a second time, but the noise isn't coming from the oil pan, the oil pan is VERY quiet. its directly coming from the downpipe, but i don't understand where.

 

did you replace all gaskets. if you really want to know where its leaking you need to have someone wear some gloves, welder gloves and some shop rags and plug the exhaust at the end and let the car idle and you will hear and feel where the leak is coming form caution!! exhaust is hot.

 

i suppose its an idea that could be tested in the morning when i can **** my neighbors off some more.. heh. i'll update tomorrow, any other ideas please keep coming!

 

sounds like exhaust leak.

 

i'm believing that also, but its one hell of an exhaust leak lmao..which i can't find?

 

You can put a vacuum cleaner outlet on the tailpipe and cap the TB to get a couple psi on the exhaust then look for leaks

 

solved it, was EITHER the wastegate flapper or the cover that goes over the journal(right next to the hotside wheel) i had the flapper welded to the arm instead of just a pin holding it...i believe thats what it was but can't say 100% sure.

 

Why did you weld it? So it was always open i guess?

 

i welded the door to the arm(what the door is connected to) to stop vibration, for some odd reason, now i'm just having a problem with spiking boost, wastegate isn't opening.