Volkswagen Passat Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1 (Edited)
Im new here Hi all! my name is Mike T from NJ,

Sorry if there is an answer to this problem elsewhere i have months googling this issue to no avail... also sorry for the book...I have had a 2003 Passat GLS 1.8t for the past 2 years... i got it for free it was neglected and sat for about a year before it was given to me... everything rubber or plastic was bad under the hood turbo was bad, sparkplugs were bad battery was bad... i spent months checking codes>ordering suspected parts, waiting for them to come in, installing them, clearing my check engine light and then driving around waiting for the next cel to pop up to find more issues with different codes... i have yet to make it through a full gas tank without a check engine light....somehow i managed to get it pass inspection... and almost a year later i finally have everything buttoned up i think(fingers crossed as far as engine suspension is my next big thing all my bushings are bad)... completely new pcv system, new turbo, new vaccuum hoses, new egr valve and housing water temp sensor, thermostat climate controll and ton of other parts....all stock minus a tectonics tuning down pipe and catback with borla exhaust. i just had a low fuel pressure CEL that i "think" i fixed(just cleared the code today after changing fuel filter,fuel pump, fuel pressure regulator and cleaning my injectors(trying to get rid of this freaking god awful noise im about to describe). car is running the best its ever been no hesitation and it pulls pretty hard so i think the engine bay is 98% good to go(i wanna do my belts and tensioners next)... but i still have an issue with the fuel system....when im idling no issues when im doing 60-80 no issues that i can hear. but when im just cruising up the street between 5 and 40mph i can hear this whuuuuuumph noise that happens from the back passenger side quarter panel or directly under the door, it happens randomly or it feels like randomly... it makes the sound anywhere from 1 second up to 10 seconds and it can happen multiple times ina row like whummmph whumphhh whuuuuuuuuuuuumphhh or just a quick one like whuumph and you can hear it if you're on the street as i drive by... when it happens it feels like the car hesitates, i dont lose rpms but you can kind of feel it push you forward in the seat just barely...

my first thought was the wheel bearing, i changed it. then i thought it was the new vw filter i had installed myself so i bought a second one same problem... tried blowing out the lines with 180psi from my compressor and cleaning the injectors using gumout a car battery and alligator clips... nothing has gotten rid of this problem....today would be my 3rd vw fuel filter since ive owned the car and its still doing it. im frustrated and out of ideas.... if i just eliminated possibility of it being the major components of the fuel system am i looking at an evap issue? charcoal canister? maybee the vent line is clogged? i dont want to install new lines if i dont have to thats not something i can do by myself on the street at my house....
any help or suggestions on what i can look into would be greatly appreciated as google is worthless for this seemingly rare issue. I tried taking it to the only VW mechanic within my county and even he said hes never seen this problem before and had no clue how to fix it other than "try another fuel filter" theres no way ive gotten 3 faulty vw fuel filters sooo i figure i either ask here or put a brick on the gas pedal and let this thing drive itself off a cliff(thats a joke id never do that even if thats how i feel about it right now)

over the past 2 years ive gone through all sorts of different codes everything from vacum leaks, to misfires, to this car being slower than moped(when i first got it), almost everything with this car has been a head scratcher as this is my first vw and i had to learn how to work on it by myself and so far the worst car ive ever owned. i wanna love this car... my fresco green b5 passat is gorgeous but this car doesnt love me back and being as im $7k in the hole so far i feel like im waaaay too far in to give up now... im sick of wasting money on this thing i just want to drive it and not feel defeated or frustrated.... Thank you for taking the time to read and thank you in advance for suggestions, ideas etc...
 

·
Moderator/Administrator
Joined
·
23,739 Posts
Stop throwing parts at it for a second. It sounds like your leak detection pump. The filter for it is behind the driver side wheel well in the rear.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #3
thank you, after looking up the part and watching a few videos i will get under there next time its nice out and at very minimum try to blow the filter off with compressed air
 

·
Registered
Joined
·
5,282 Posts
The LDP is behind the left-rear wheel liner, and has an electrical connector that can be disconnected to disable it, for a test. Normally that thing is too quiet to hear on the road, but maybe there is a serious defect with yours.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #5
i have a theory that the car isnt able to vent fuel vapor properly, or the return has some kind of partial blockage and the whining at my fuel filter occurs when the pump is trying to add more gas to the system but cant or theres too much vapor pressure, i dont have enough of an understanding of the complete system as a whole when you add in leak detection and the vapor part of it, but i plan on going out to inspect everything connected to the LDP and at bare minimum blow the filter off with an air compressor before i put it back together and order any needed hoses or parts if that doesnt solve the problem.... im also going to take off the n80 valve(i think thats the name) pull the boot off and see if theres charcoal pellets in it from the canister, but im pretty sure that one was replaced when i did my suction tube and egr valve egr housing housing becuase if i remember properly one of the barbs were cracked and all of the hoses were bad as well...
 

·
Registered
Joined
·
4 Posts
Discussion Starter #6
ok so i cleaned the LDP filter. it was horribly dirty and in horrible shape as the rubber at the top and bottom looked like it was about to fall apart just from touching it,the hoses looked to be okay though so i guess that saved some money for now... will order new parts when i get paid again. and i checked the n80 purge valve; i could blow through it so both the filter and the valve are bad... Also, while i was out with the fiance so she could grab toilet paper and water and we were driving from store to store becuase of the human malware thats going around my little fixd module popped up with a p2404 which is a generic code for leak detection sensor circuit which is the first time ive gotten that error no CEL though yet. test drove car after checking tire pressure while i had the compressor out and the fuel filter still sounds like its fartin while driving... another note: i got in my trunk while the car was idling and there is defintely a sound coming from the LDP now that wasnt there before so i may have to replace that as one unit instead. need to think on it if its worth the $340ish for a new one from ecs or if i should try to find one at a junkyard or if i should just buy another passat and use it for parts(i kind of want a leather interior anyway so this may just be the excuse i need to do all that)..its kind of squeeling all the time but its not so loud that you can hear it in the front seats or the rear seats when they are up... ill update when i figure out the game plan... might even just trade it in for another car with income tax when that gets here or sell it for $4000 and cut my losses on what i put into it....
 
1 - 6 of 6 Posts
Top