runningallday
Well-known member
Stock ALH. 40 seconds of acceleration in 2nd and 3rd gear.
Exhaust restriction sounds possible. Air filter is new. Can maf be diagnosed from these graphs? Other signs of a worn turbo?Bad maf, worn tuebo, exhaust restriction? Air filter dirty?
alright sweet. VCDS is awesome, i can actually slowly track down the problem this way. although, all in all the car is running pretty good... just wondering if it had a little more power at the high endUsually the maf readings will read above 800mg/str during a hard 3rd gear pull. A good maf will read well above 1300mg/str. If it doesn't, a bad maf is suspect. I'd refresh the vacuum lines and test again, cause if the turbo isn't actuating correctly it won't have enough airflow to raise maf readings.
well here's the plan. i'm going to swap out the vacuum tubing soon, that should be done anyway. and i have a new MAF on the way, that's only $60 for a bosch. those are the easy repairs. the intake was last cleaned around 100k miles ago, it's due for a cleaning, honestly i think this is the most likely culprit... if it's not solved after that, then i could replace the catalytic converter, looks like you can get one off ebay for $130? I'd prefer not to make my car louder in any way, and as tempting as it is to punch a hole in it, i don't think i'd be happy with the smell/noise. do you know if the muffler/resonator might also need to be replaced?If boost actual is tracking with requested and known good maf then most likely a restriction on the intake or exhaust. With the intake plugged a drop or flatlining in maf readings usually tracks instantly with a drop in power. If it's exhaust there's usually a slight delay between the flatlining in maf readings and the noticeable drop in power.
At first glance I didn't see anything significant. But I only peeked in the easily removed part on the left of the EGR. The MAF sensor should be arriving Friday, that's an easy swap. I also picked up a mityvac so I'll test my vacuum tubing before and after swapping it, haven't done the vacuum tubing yet either.Have you looked inside the intake manifold through the EGR valve (or removing the valve) to see if the intake is clogged?
Only costs an EGR o-ring & some time.
I would hold on the exhaust side for now.
I replaced my MAF sensor, no change. The previous MAF sensor seemed to underestimate the air flow by maybe 10-15% though? Yours changed after you swapped it out?I had a MAF on my 2002 that would hit 850 under full throttle then wander down to 500. No Check Engine light as VW did not anticipate this failure mode
I don't have a torch with me, and I think I need to heat up some nuts to remove it? I think when I visit some friends for Thanksgiving I can work on it then. I'm planning on boiling the intake manifold with some baking soda and dish detergent, that seems pretty safe and I anticipate it would work pretty well and be lower risk than burning it out.Uh, that's nasty -- take it off and clean it.
You wouldn't happen to have some diesel fuel laying around would you?I don't have a torch with me, and I think I need to heat up some nuts to remove it? I think when I visit some friends for Thanksgiving I can work on it then. I'm planning on boiling the intake manifold with some baking soda and dish detergent, that seems pretty safe and I anticipate it would work pretty well and be lower risk than burning it out.
i got the 'intake manifold kit' from urotuning: https://www.urotuning.com/products/...-all-tdi-1993-2007-aaz?variant=32196527063095You wouldn't happen to have some diesel fuel laying around would you?
Take it off, soak in 5 gallon bucket full overnight, run brush down it, repeat, then use a few cans of brake cleaner on what's left. Not as fast as the "fire fire fire" method but it certainly works.
No real drama in getting it off most of the time other than reaching around things. You do need a new gasket.