Hesitation, REVO, MAF problems?

[pixelsherpa]

In January, I did the REVO trial, loved it. Decided same day to purchase and do the official install.

Had the official install run, and later that day noticed a significant delay/hesitation starting (accelerating) from a stand-still. Would give it gas, and practically nothing happened until about 2300rpm, then massive boost.

Returned to the shop, ran the vag com and it was determined the mass airflow sensor was bad. (Sorry , only details I remember was that there was a -25% reading on the right side...or something). This was my first week with the car so dont know the history, 2003 w/ 35k miles.

I had it replaced, and performance was fine for about 1.5 months, and same symptoms returned. Took it to my regular shop and same reading (-25%) \, replaced the MAF again. The car accelerated smoothly again (or at least better, all relative at that point)

Now, Im getting the hesitation again. Wondering what might cause the MAF to deteriorate? or if anyone has another idea what might be happening here if it is not the MAF?

I should also mention - the hesitation is much more pronounced in the mornings after startup, not as severe once the car is warmed up

[RLB6]

Make sure the MAF wire harness and it's wires are in good condition. One faulty connection amongst those wires can prematurely kill a MAF. A member here had that same problem and it turned out to be a faulty wire (exposed I think) in the MAF wire harness. Atleast start there.

In January, I did the REVO trial, loved it. Decided same day to purchase and do the official install.

Had the official install run, and later that day noticed a significant delay/hesitation starting (accelerating) from a stand-still. Would give it gas, and practically nothing happened until about 2300rpm, then massive boost.

Returned to the shop, ran the vag com and it was determined the mass airflow sensor was bad. (Sorry , only details I remember was that there was a -25% reading on the right side...or something). This was my first week with the car so dont know the history, 2003 w/ 35k miles.

I had it replaced, and performance was fine for about 1.5 months, and same symptoms returned. Took it to my regular shop and same reading (-25%) \, replaced the MAF again. The car accelerated smoothly again (or at least better, all relative at that point)

Now, Im getting the hesitation again. Wondering what might cause the MAF to deteriorate? or if anyone has another idea what might be happening here if it is not the MAF?

I should also mention - the hesitation is much more pronounced in the mornings after startup, not as severe once the car is warmed up

[pixelsherpa]

UPDATE*

Have had the car in for service/investigation twice since this post - replaced the O2 sensor (had fault code), cleaned the throttle body. No improvement. Was told to take it to the dealership as it could be the catalytic converter which would be covered under warranty.

Just received a call that they (Audi dealership techs) have been manually testing a number of potential causes but are clueless. Several techs have collaborated ideas and tested but no ideas.

frustrating - any advice? I will post the list of tests completed later today when i have it

[Howard Hughes]

Do you still have a stock dv? Although it sounds like you have maf symptoms...
A messed up DV might give you surges in power...

[pixelsherpa]

I do have a stock dv. One of the techs I spoke with ruled that out because the hesitation/subtle stuttering occurs only around 2300-2500 RPM when accelerating. He said a bad DV would be sporatic and more noticable. Agree?

I am currently running in stock mode (REVO off) and same issues just less obvious

The techs noticed poor performance/power right away, so not just me

Do you still have a stock dv? Although it sounds like you have maf symptoms...
A messed up DV might give you surges in power...

[pixelsherpa]

starting to suspect this is why I found this car used with 35k miles, hmm

[initiala4]

Do you have a K&N??

[pixelsherpa]

no, at least not that Im aware of.

[pixelsherpa]

Heres the testing procedures done - still no answers and the shop gave up. Im stuck.

• Completed GFF test and found no faults stored
• Checked Iginition coils/sparkplugs
• Visual inspection of engine components, connectors, harness routing, air feed pipes, and intercooler, exaust for damage/restriction.
• Attempted to reset readiness and cannot
• Systems that will complete test are O2 sensor control and sec. air injection fails test=system leak. Cannot verify failure through testing.
• Tested for vacuum leaks, none found.
• Need hard fault to be stored and present.

Another 4.5 hours testing with no results. frustrating.

[pixelsherpa]

Thanks to all of you for your help and advice, thought I would give an update.

Just over a year, and $1500 later - problem solved.

Last week my Turbo crapped out - whining sound, blowing light grey smoke and all. Had the turbo replaced and all of the symptoms above are now resolved. Pretty frustrating that a turbo would go out at 50k miles!

Wanted to share in case anyone starts experiencing similar problems

[pixelsherpa]

Guess Im not done yet.

About a week after the new turbo was installed I was hearing a noise like a pressure release when i let of the gas abruptly and the turbo seemed loud.

My mechanics say the turbo has been damaged due to unknown cause - something else going on.

Again getting negative readings on the Group 1 vag-com (I can get more details if this seems like critical info) - dont remember exactly but range should be between 0-10 and mine is a -25 – apparently indicating a mass airflow fault again

We removed the MAF and it runs great, better than ever infact! - i do still have a somewhat noisy turbo that WAS brand new and now damaged. ugh

This car is under the Oil sludge extended warranty (enacted by previous owner) - anyone have experience with or been a victim of the oil sludge issues?

Does this sound like a side effect that could be related?

[gq9]

Guess Im not done yet.

About a week after the new turbo was installed I was hearing a noise like a pressure release when i let of the gas abruptly and the turbo seemed loud.

My mechanics say the turbo has been damaged due to unknown cause - something else going on.

Again getting negative readings on the Group 1 vag-com (I can get more details if this seems like critical info) - dont remember exactly but range should be between 0-10 and mine is a -25 – apparently indicating a mass airflow fault again

We removed the MAF and it runs great, better than ever infact! - i do still have a somewhat noisy turbo that WAS brand new and now damaged. ugh

This car is under the Oil sludge extended warranty (enacted by previous owner) - anyone have experience with or been a victim of the oil sludge issues?

Does this sound like a side effect that could be related?

You ever correct this problem? I'm experiencing the same shit.

[texasboy21]

I wonder if you have a stage 1+ without the injectors

[gq9]

I wonder if you have a stage 1+ without the injectors

I have injectors as well as revo. If OP does too, shieet.

[gq9]

No one has any suggestions about this at all, that's hard to believe.

[widgget]

Keep in mind that by chipping the car (or ANY power increase you add) will put more stress on everything from the intake to the axles, if you have some week links in there they could fail. the whole boost system is a good example. those 6 year old check valves get brittle from the heat that the 1.8t puts out, 8psi might not be a problem for them but flash it and that pressure goes up to 18 to 20psi which they just can't handle and they fail. not the softwares fault, just the way it is.

sludge could clog the oil lines to the turbo causing it to fail early.

make sure you warmup and cooldown!
i ALWAYS idle my car for 60 seconds before driving, don't go past 3k / don't boost until it's completely warmed up, and ALWAYS ALWAYS ALWAYS let it idle for at least 3 minutes after driving it to properly cool everything down. after killing 3 other turbos i am not going to take any chances, and so far this one has lasted WAY long then any of the others.

the pressure release sound could be the DV. the stock one simply won't hold the boost that a flash adds. if it's not already blown then it won't be long. might as well put in a nice one to rule out that being the issue since you should do it anyway.

good luck.

[gq9]

Keep in mind that by chipping the car (or ANY power increase you add) will put more stress on everything from the intake to the axles, if you have some week links in there they could fail. the whole boost system is a good example. those 6 year old check valves get brittle from the heat that the 1.8t puts out, 8psi might not be a problem for them but flash it and that pressure goes up to 18 to 20psi which they just can't handle and they fail. not the softwares fault, just the way it is.

sludge could clog the oil lines to the turbo causing it to fail early.

make sure you warmup and cooldown!
i ALWAYS idle my car for 60 seconds before driving, don't go past 3k / don't boost until it's completely warmed up, and ALWAYS ALWAYS ALWAYS let it idle for at least 3 minutes after driving it to properly cool everything down. after killing 3 other turbos i am not going to take any chances, and so far this one has lasted WAY long then any of the others.

the pressure release sound could be the DV. the stock one simply won't hold the boost that a flash adds. if it's not already blown then it won't be long. might as well put in a nice one to rule out that being the issue since you should do it anyway.

good luck.

I'm on board with all that you said, but. My car rarely starts up the first time after sitting for over 5 hours. So that is from night to the next morning, my car will not start on the first key turn. Once it does start, and warms up rpms drop as usual and running normal. After that period if I give the car gas it will have a hesitation that is easy to pickup on before the car reaches 2k rpm. That's not normal, and is what I'm trying to figure out.

I've changed my coolant temp sensor because the car had thrown a code for that being bad. I had hoped that would fix this hesitation problem but it's still there.

I do not have a boost gauge either, so I can't say if this is a problem with boost. To be honest I don't know that much about the whole system, so if this is a common problem related to that.. I wouldn't know

[A4Dit]

Keep in mind that by chipping the car (or ANY power increase you add) will put more stress on everything from the intake to the axles, if you have some week links in there they could fail. the whole boost system is a good example. those 6 year old check valves get brittle from the heat that the 1.8t puts out, 8psi might not be a problem for them but flash it and that pressure goes up to 18 to 20psi which they just can't handle and they fail. not the softwares fault, just the way it is.

sludge could clog the oil lines to the turbo causing it to fail early.

make sure you warmup and cooldown!
i ALWAYS idle my car for 60 seconds before driving, don't go past 3k / don't boost until it's completely warmed up, and ALWAYS ALWAYS ALWAYS let it idle for at least 3 minutes after driving it to properly cool everything down. after killing 3 other turbos i am not going to take any chances, and so far this one has lasted WAY long then any of the others.

the pressure release sound could be the DV. the stock one simply won't hold the boost that a flash adds. if it's not already blown then it won't be long. might as well put in a nice one to rule out that being the issue since you should do it anyway.

good luck.

Cool down procedures are not needed on an aftermarket turbo with ceramic ball bearings. If it is a coolant cooled turbo you are simply wasting your time. Look it up on Garret's website.

[gq9]

bump