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View Full Version : Turbo pressure noises and rare misfire



aenima4
12-23-2007, 04:38 PM
This is a little different than the common misfires we all read about everyday and the noise coming form the front of the car is very concerning.

the car is a 2000 a4 1.8t qms.

To start things off i have replaced the MAF due to a misfire and vag-com showing crazy readings(fixed miss) then lost coil packs a month later so replaced those (fixed miss) and i have run vac checks on the lines with soap and pressure testing. i am chipped.

Now for what is occurring. Say i am on the highway and and needing to pass someone. Fifth is more than enough so i hit the gas a lil harder and feel the turbo come in and start to catapult that car faster. as i am doing this i will get one to two misfires and a constant woooooshh while holding about 16 psi. the woosh is now a lot louder but the misfires are the same...

This only happens when i am in a gear and around 2-3k rpms with a substantial load on the motor.

I do get a lean code in vag com on bank one.

Does anyone have any ideas on further tests i can run to get a better idea of whats goin on?

2001A4QUATTRO
12-24-2007, 09:48 AM
Sounds like a bad Diverter valve. Check it LMK

FYI you should have atleast a 710N if you are chipped.

SykoraA4
12-24-2007, 04:37 PM
my car was doing something like this, and it turned out my plugs werent gapped properly. I had denso iridiums gapped at .044 or something. because youre chipped, they are supposed to be gapped at .028. i swapped them out for champions with the proper gap and havent had any problems since.

aenima4
12-25-2007, 07:09 AM
I have ngk-r's right now gaped at .028 and they seem to be doing fine. My concern is the woosh....im testing the dv today and saw ecs has the oem 710n on sale for 30-40 bucks so i may just use xmas money for that.

im looking for spring action on the dv right?

circafuc
01-09-2008, 11:30 PM
my car did the same thing im only stock but i broke a vacum line off on the turbo and it would drive fine unless u tried giving it gas at a low rpg n then letting off turbo just dies down and bogges the car very bag i replaced a bango bolt on my turbo and runs fine now