Unsolvable Two Litre Trouble

[whatyourbeef]

So my wife has an 08 A4. Bought it around 2 years ago. Right now its sitting at arond 185000 Km (115 miles). Started having trouble with it about a year ago, when it was cold and you would get up to speed the RPM would kind of bounce up and down maybe 150 RPM. it stopped once the car warmed up so i never thought much of it. Then it started doing it at idle, RPM bounced 200 or so up and down. shook the car and sounded like it was going to die. Took it to a shop where they replaced the coil packs i believe. it might have fixed it for a few days but then it continued. Next they tried the pcv valve. still nothing. the Check Engine Light was on, and when i would clear it the idle would clean up for a while but start up again after a drive. I believe the next thing they told her was that the throttle body needed to be replaced. not wanting to spend the money we left it. i took the throttle body off cleaned it up and everything seemed fine with it. eventually she took it back to them, they said if the throttle body was not the problem they wouldnt charge for it. so she let them do it, and big surprise it fixed nothing, bigger surprise they would not refund her money. they removed the pcv valve and blocked it off, said it was a temporary fix. told her the engine harness needed to be replaced. she called the next day to get a quote to replace the harness (just for a laugh) and they told her they were not interested in working on her car anymore. so car sat for 4 months or so, now needing a vehicle to drive we were forced to start driving it again. the pcv valve is still blocked off so it idles fine but the other day on her way to work she told me the car would not go over 80 km/h said it would shift down and rev up but wouldnt go over that speed. on her way home it magically fixed its self. but has happened again once since. i have no idea what to do with this car. im sick of spending money on it, but it cant be sold in its current state. check engine light comes on sometimes goes off other sometimes. its currently off or i would write the codes down. anybody have any ideas?

[mtroxel]

1. Your shop hasn't guessed right yet, stop going to that one.
2. Find a shop that does Audi's, might even be the dealer. But someone who can VCDS that motor and see what's going on. Whatever it costs, it's less than the beating you'd take if you sold it this way.

[Denio24]

What do you mean they removed the pcv valve and blocked it off? Any pictures to show what is happening under the engine bay?

[onedumslack]

As mtroxel says, get the car scanned. If you can get it scanned with vag com and post the codes here people might be able to help with what's wrong. And definitely go to a new shop that specializes in vw/Audi.

[whatyourbeef]

1. Your shop hasn't guessed right yet, stop going to that one.
2. Find a shop that does Audi's, might even be the dealer. But someone who can VCDS that motor and see what's going on. Whatever it costs, it's less than the beating you'd take if you sold it this way.

The shop it was at was a Audi/VW specialist. The car throws about 6 codes all at once which is why they said they had to try to eliminate possibilities. What is the difference that they can see with a Vcds compared to was regular obd2 scanner? Thanks

[whatyourbeef]

What do you mean they removed the pcv valve and blocked it off? Any pictures to show what is happening under the engine bay?

I'm not sure if they removed it or just blocked it off. I'll grab a picture when I can. I really don't know these cars sorry if I'm a little slow. From what I remember they had a hose with a plug in the end underneath the plastic engine cover.

[Charles.waite]

And this is why I never trust shops with my car. They just play parts darts until they hit something that sorta kinda fixes it.

[mtroxel]

What is the difference that they can see with a Vcds compared to was regular obd2 scanner? Thanks

You see pending codes (codes that are not triggering a check engine light), and can see/log data in real time. That would be invaluable for your issue. Less important to your issue, you can also adjust, or recode, modules.

Whatever your shop is, I don't have faith in them. Replacing coil packs seems to be everyone's "go to" solution when they don't know what's going on. You would do that if you knew the problem was in the ignition system. And if they had good reason to believe the problem is in the ignition system, why would your next guess be to replace the PCV valve? Then they jump to the throttle body......I could go on and on. I don't think these guys have a plan. They're just throwing parts at it.

Go to the dealer.

[KJack]

Torque converter issue? See this thread, scroll down a bit:

http://www.audiforums.com/forum/b7-m...ulsing-178931/

[mtroxel]

KJack, thought of that one too. I'd be interested to know if the surging idle goes away if you put it in Park.

[Charles.waite]

Having had the torque converter issue on my previous b7 this issue sounds different but I suppose that could be a possibility too.

[1killera4]

get it scanned by an Audi shop. Engine Harness...lmfao

[B72011]

If I were you Id go down to the court and get the paperwork for a small claims suit (if they have that in Canada --or the equivalent)--fill it out and then slap it down and say ---you need to refund me the amount of $ you agreed to -or I'll file. You'll at the very least have to take time to show up to defend the suit--or by default I win and you will pay no matter what.
That works sometimes to get people to honor what they claimed in the first place.
If the truly feel you are wrong sometimes they're hard headed---but no one wants a summary judgment--so they'll at least have to show up---or theyre dunzo!

[billyhoyle]

Where in Alberta are you? If you're in Calgary, Tunedub is the place to go for VW/Audi work.

[pkny]

The shop it was at was a Audi/VW specialist. The car throws about 6 codes all at once which is why they said they had to try to eliminate possibilities. What is the difference that they can see with a Vcds compared to was regular obd2 scanner? Thanks

OBD2 scanners spits out generic codes. VCDS codes are more specific and would lead the mechanic to the potential problems. A log of what could be wrong would also be a tale tale sign whats happening with the car.

[Jake@JHM]

And this is why I never trust shops with my car. They just play parts darts until they hit something that sorta kinda fixes it.

There are reputable shops out there though that actually know what they are doing. We get customers coming to us all the time because the shop their car was has been changing parts and not just diagnosing the problem.

We even get cars where other shops tell them they need a new engine and we find it was something simple like a spark plug. (true story)

[Axis]

get it scanned by an Audi shop. Engine Harness...lmfao

[hypothesis]Shop probably said throttle body harness since they mentionned replacing the TB and OP states engine harness by mistake. There's a tsb for the throttle body harness. Car is probably giving codes pointing in that direction.[/hypothesis]