Help Please 2010 A4 B8 CVT juddering at 2200RPM

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Simon Moore

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Hi Guys ,

I've been searching on here and also on the net, but can't seem to find any help for my issue.

So I bought a 2010 A4 B8 2.0 TDI CVT (CAG engine code) last week with 130k miles. Purchased it with a few issues including possible gearbox troubles. I've driven it about 500 miles so far, and just wanted a little advice as to whether you guys think my issue is gearbox related or what else I can check first.

So the car starts perfectly, and there is no jerking or clunking whatsoever when selecting Drive or Reverse. It drives 100% spot on up to about 2200 revs , then it starts shuddering , and loses power The shuddering is not violent, almost like going over a rumble strip. The only way to be able to continue driving it, is to ease off the accelerator and allow the revs to drop below 2,200rpm and then its happy again. In all honesty I've adjusted my driving to it , but the moment you go over 2,200rpm the shuddering and loss of power starts again, there is no slipping whatsoever. Something else to mention if it makes any difference is the cruise control works just fine, and on the motorway I have just been using that.

I have swapped over the MAF with another genuine one off my A6 (same part No) and it made no difference. My friend who is a mechanic scanned it with his snap on tool and no error codes were present. Prior to my purchase it has had a ton of works done , including cambelt, Inlet manifold, gearbox oil change and a ton of other bits and pieces.

Just seeing if anyone has an idea of what else it could be. I am expecting it to be worst case scenario and need a new CVT box, but I have had a few CVTs before and it seems very strong upto 2,200rpm , hence me wondering if it may just be something else.

Any advice would be greatly appreciated,

Thanks ,

Simon
 
seems like an engine issue rather a gear box one, as it's related to rpm rather than speed of car.
 
No excessive movement of the engine in those videos.
Strange one, how long has it been doing it?
Have you had any work done on the car recently.
How long have owned the car?
 
audiwaterpump said:
No excessive movement of the engine in those videos.
Strange one, how long has it been doing it?
Have you had any work done on the car recently.
How long have owned the car?
Click to expand...

I purchased it like this recently fully aware that it might be a gearbox issue or something lesser. As mentioned in my first post, I've adjusted my driving to it, but obviously I'm curious to try and work out what it potentially is.

The cars had a ton of works done to it recently, intake manifold, loads of hoses, cambelt kit (and timing has been checked again) , gearbox oil , and lots of odds and ends. I have also changed the MAF with a genuine one off my A6 (Exact same part code) and made no difference
 
Simon Moore said:
I purchased it like this recently fully aware that it might be a gearbox issue or something lesser. As mentioned in my first post, I've adjusted my driving to it, but obviously I'm curious to try and work out what it potentially is.

The cars had a ton of works done to it recently, intake manifold, loads of hoses, cambelt kit (and timing has been checked again) , gearbox oil , and lots of odds and ends. I have also changed the MAF with a genuine one off my A6 (Exact same part code) and made no difference
Click to expand...
This may provide us with a clue.
Why was all that work required?
Turbo failure? Cam belt break, and hence damage to the engine?

Look at vacuum leaks
If manifold has flaps, they may be sticking.
Dual Mass Flywheel.
Double check engine mounts.

Non oem parts, or poor workmanship, or both.

Seems like engine, and not the gearbox.
 
audiwaterpump said:
This may provide us with a clue.
Why was all that work required?
Turbo failure? Cam belt break, and hence damage to the engine?

Look at vacuum leaks
If manifold has flaps, they may be sticking.
Dual Mass Flywheel.
Double check engine mounts.

Non oem parts, or poor workmanship, or both.

Seems like engine, and not the gearbox.
Click to expand...
thanks , I'll have a good look over it and report any findings. If I can't find anything obvious, I think the next option is going to be to find a VAG specialist to give it the once over.
 
So, when this occurs, are you actually losing power or are you losing drive? Does the engine seem to bog down at all?

If you try accelerating through it, what happens? Does the engine bog down or do you just not get the power to the drivetrain?

If you're experiencing bog down, I'd be inclined to think injectors or hpfp.

If you're just not getting drive, I'd be looking at the dmf, checking gearbox oil is the correct stuff, and failing that gearbox internals for bearing or gear damage.
 
Garrett 69 said:
So, when this occurs, are you actually losing power or are you losing drive? Does the engine seem to bog down at all?

If you try accelerating through it, what happens? Does the engine bog down or do you just not get the power to the drivetrain?

If you're experiencing bog down, I'd be inclined to think injectors or hpfp.

If you're just not getting drive, I'd be looking at the dmf, checking gearbox oil is the correct stuff, and failing that gearbox internals for bearing or gear damage.
Click to expand...
When it occurs its actually losing power, I'm putting my foot further down on the accelerator but the speed is decreasing and the revs are just holding around 2.4k. I have tried accelerating through it and it just won't have it. The power just decreases and the car slows down. Have to take my foot off the accelerator and let the revs decrease, then its ok again. It's like the revs are being choked. My friend who had a very quick look and drive also mentioned he thought injectors, and he scanned it (With his Snap-On machine) and there were no error codes whatsoever. Would injectors or HPFP not throw a code?
 
How many owners has the car had?
The previous owner should be able to point you in the right direction, if they are contactable & willing.

Other than that, you need VCDS and start looking at live data at those revs.
But the vibration indicates something is out of balance/loose at those revs, and the car is cutting the power to prevent catastrophic damage occurring.

Is it still the original turbo, if so it may be on its way out.
 
Thinking about it, those sort of revs are smack in the turbo pickup range so it could well be a ****** turbo. I didn't consider it because they way I read the OP, the turbo had been replaced?

I'd be popping the air intake off and checking the shaft for any play and any vane damage.

Edit:

I think I must have imagined the turbo bit or had my head in another thread.....
 
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audiwaterpump said:
How many owners has the car had?
The previous owner should be able to point you in the right direction, if they are contactable & willing.

Other than that, you need VCDS and start looking at live data at those revs.
But the vibration indicates something is out of balance/loose at those revs, and the car is cutting the power to prevent catastrophic damage occurring.

Is it still the original turbo, if so it may be on its way out.
Click to expand...

3 previous owners. Car was bought with this issue , the gent I purchased it from was totally honest about it , and he’d done a load of bits and princes to it to try and resolve the issues as mentioned in the initial post.

the turbo has not not been replaced (at least not by the previous owner and I have no record for it) , so yes that could be a good place to look next.
I’ll have to try find a garage local that has VCDS
 
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Garrett 69 said:
Thinking about it, those sort of revs are smack in the turbo pickup range so it could well be a ****** turbo. I didn't consider it because they way I read the OP, the turbo had been replaced?

I'd be popping the air intake off and checking the shaft for any play and any vane damage.

Edit:

I think I must have imagined the turbo bit or had my head in another thread.....
Click to expand...

thanks for the post , I’ll have to look into this next , if it is a faulty turbo then that wouldn’t be too bad at all. Now to find out how to remove the air intake ;-)
 
Little update, so the EML came on at the weekend, I've had it scanned again by my friend and it came up with two codes P010200 Mass Volume Air Circuit Manifold Position Sensor , and P201500 Intake Manifold Runner Position Sensor. My friend who is a mechanic said he's sure it's not the gearbox which is a positive sign. I've read online about fitting a bracket on the Intake Manifold Runner Position Sensor, and it appears this has already been fitted. (Mine has the plastic manifold) The manifold is appears to be brand new as is the Intake Manifold Runner Position Sensor.

Any other suggestions what to look for guys? I have tried changing the MAF with the one on my A6 which is identical part number and that made no difference.

Thanks in advance for any help you might be able to offer
 
Another thing I just tried, disconnected the MAP sensor and the car was totally sluggish with the glow plug light flashing as to be expected, however it revved freely , well over 2,200 rpm. Would this indicate that it could potentially be a MAP sensor issue?
 
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