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Discussion Starter #1 (Edited)
this would be the second post im making about this, my b5 farts while driving; the sound started at the fuel filter and after changing a lot of parts now comes from my LDP. it started after i had a vw shop do my turbo and oil lines and half moon gasket. i assumed it was a fuel system issue or something they put back together wrong; then i thought it was evap or leak detection, since ive owned this car for 2 years now, I've replaced fuel pump, fuel filter three times, regulator, n80 valve, injectors, egr valve and housing, entire pcv system, valve cover gasket, throttle body gasket, intake manifold gasket, leak detection pump, engine snub mount, transmission filter and refill, transmission mounts, tectonics tuning exhaust and down pipe with custom welded exhaust tip out of the rear bumper, intake box delete to pod filter and breather filter on Sai, intake tube with silicone, diverter valve, n75 valve, vacuum lines, maf sensor spark plugs, coils, the entire suspension is brand new and aligned properly..... the only things i haven't changed in the engine compartment are the n249 valves, the vacuum reservoir, my brake booster/master cylinder, and the map sensor the fuel lines and the line that runs from the vacuum reservoir to the LDP.

so a bit about the farting sound, anytime i have my foot stable on the gas pedal while driving it makes a whmmmmmmmf sound. its kind of like a rumble strip without the vibration in the steering wheel... the sound can happen from .5 seconds to 30 seconds or longer if i don't move my foot and begins about 10 to 15 seconds after my foot gets positioned or happens if i abruptly let off the gas and comes from the back left of the car. the second i give it more gas or release the pedal it stops but if i hold it there, it just farts . it tends to mostly happen at a steady 1500 rpms and 2000 rpms. i took it to one shop and they let my car sit for 5 months and did nothing with it, i took it to another certified VW shop(not a stealership) and they thought it was my transmission fluid levels causing a "harmonic vibration" so they did a new filter and refill i took it back to them 4 times so far and they cant figure it out. Thier lead mechanic of 30 years has never seen a problem that stumped him like this one. they couldn't replicate the problem on the lift. they changed my check valves, my trans mounts, they made new hangers for the exhaust, made sure everything on the underside of the body no longer made noise. he believes that the problem isnt in my fuel system or my evap system or my leak detection system and still thinks its a vibration caused by something metal but im still not sold that its not either a restriction in my fuel lines my ldp lines or my vacuum reservoir is bad which he refuses to acknowledge that it could be any of that.. i also think it could be an n249 valve but im not sure because i don't fully understand what that valve does or what systems the two n249s that are in my car are actually hooked up to if they are even connected to the LDP or fuel system at all..... my best guess is that when the ecu tells the ldp to check for leaks its looking for air or vacuum that isnt there or theres too much of it so the pump struggles and causes a whine? or when theres too much fuel vapor in the system its causing too much pressure?...idk anymore and im sick of guessing and throwing money at this car when i could have bought a new used car without all these problems by now and this is the last engine/drivetrain problem i have left. i dont want to give up though! i love the looks of the b5 and the way it handles i just need this car to not leave me cringing every time i hear that sound.

im about 8k in the hole here which is about double the cars bluebook and this problem is stubborn to the point that I've never felt so defeated by a car. i wanna love this thing but it must hate me, i mean shame on me for fixing it up right? lol.... the rest of the engine, drivetrain and suspension is solid now after all that money into it i finally dont have any cels for 2 full gas tanks now for the first time ever and its finally reliable and safe otherwise but its embarrassing when the car is farting people can hear it outside the car and inside and being as that turbo was one of the first parts i put into it its been doing this the entire time I've been driving it.

anyone got any ideas or suggestions?
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