No supercharger boost

[shezza]

What a slow car without boost!
Came out of the petrol station yesterday and the car was sluggish, I put my foot down, the car revved out to 7k or so and then my car went into limp mode (Max 1500 revs). I turned the car off and on, it let me drive, though I was blinded by my check engine light all the way home!
Plugged in my obd reader and came up with P0235 (Supercharger boost circuit A). Unfortunately my vag reader isn't with me for more information. Pulley is spinning and the bypass valves internals look fine and it's freely moving. All the vacuum lines I can see look fine and I can't hear any leaks. Not sure where to next...

[jcoleman_11]

Most likely a faulty pressure sensor. There’s one on each side of the supercharger.


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[shezza]

Driving today, my harmonic balancer (crankshaft pulley) came apart today while driving. My first thought was the supercharger was seizing, putting extra pressure on the pulley, though it spins fine. Other thought was the harmonic balancer was already falling apart causing slipping, though the belt looked fine every time I checked. Surely the two issues are connected though!

[f4m0u5]

the crank pulley are known to fail on the 3.0t engine especially if running higher then stock boost

how many miles and what are you running for a tune?

[shezza]

the crank pulley are known to fail on the 3.0t engine especially if running higher then stock boost

how many miles and what are you running for a tune?

Oh really? That's good to know!
I have 87,000 miles. I only have a stage 1.
Any obvious link between my original issue and the pulley? Or does it seem like we're looking at a coincidence?
I spun all the pulleys and accessories, they all spun freely besides the alternator. Are they normally quite heavy to rotate? Though if it was seizing, I'd expect intermittent charging issues, never had any.

Is the pulley fairly straight forward to remove?

[f4m0u5]

Oh really? That's good to know!
I have 87,000 miles. I only have a stage 1.
Any obvious link between my original issue and the pulley? Or does it seem like we're looking at a coincidence?
I spun all the pulleys and accessories, they all spun freely besides the alternator. Are they normally quite heavy to rotate? Though if it was seizing, I'd expect intermittent charging issues, never had any.

Is the pulley fairly straight forward to remove?

def pretty straight foward, pull the bumper and belly pan, pull the radiator support foward ( aka service mode) then loosen the belt tension and R&R the pulley. make sure to mark orientation of original pulley since 1 of the holes is slightly off compared to rest.


personaly i would get a upgraded single piece pulley from jhm or something and not buy another oem. Doing so your replacing a factory prone part and adding a lot of torque down low. You would also need supporting software ofcourse

[shezza]

def pretty straight foward, pull the bumper and belly pan, pull the radiator support foward ( aka service mode) then loosen the belt tension and R&R the pulley. make sure to mark orientation of original pulley since 1 of the holes is slightly off compared to rest.


personaly i would get a upgraded single piece pulley from jhm or something and not buy another oem. Doing so your replacing a factory prone part and adding a lot of torque down low. You would also need supporting software ofcourse

Thanks for that. I found a low ks cheap one to get me going for now. I'll look into changing it again soonish before it fails.

I read a post saying you could get away without taking off the bumper and moving to service mode. Though if it's simple to do and makes it that much easier, may as well. Is it quite simple?

[joejoe3]

Thanks for that. I found a low ks cheap one to get me going for now. I'll look into changing it again soonish before it fails.

I read a post saying you could get away without taking off the bumper and moving to service mode. Though if it's simple to do and makes it that much easier, may as well. Is it quite simple?

I asked the same question in another post
Jhm responded and said they were able to do it in their s4 with a 207mm pulley. There’s a thread on the s4 board that shows how to do it in 30min as well (without service position).

I would recommend try doing without, and if you can’t get to it then pull the bumper

[shezza]

I asked the same question in another post
Jhm responded and said they were able to do it in their s4 with a 207mm pulley. There’s a thread on the s4 board that shows how to do it in 30min as well (without service position).

I would recommend try doing without, and if you can’t get to it then pull the bumper

It is a tight squeeze, my arms were pretty red by the end of it, but glad I didn't have to move them in the end. Thanks!

[joejoe3]

It is a tight squeeze, my arms were pretty red by the end of it, but glad I didn't have to move them in the end. Thanks!

That’s great! How long did it take you?
I’m tackling mine when the weather gets warmer.

[shezza]

ThatÂ’s great! How long did it take you?
IÂ’m tackling mine when the weather gets warmer.

Changing the pulley itself, probably an hour or so. I only had a quick look at the bumper removal and shifting the radiator forward, looked like it would be harder, though the tight squeeze is the only reason it took more than 20 minutes really, so something to consider. The tool I lacked was a very short extension. As in the shortest an extension can be... I had a very short extension, but it still was not short enough. Imagine the size of an adapter (1/4 to 3/8 for example), that is how short I needed and they don't seem all that common. I ended up using a swivel joint, though it was far from easy. I also had an air ratchet. It was very hard to get my hand in there to hold the socket in place as the bolt came loose and the reload turn of the ratchet was spinning it back in. It is most definitely a challenge!

Other thing to note, I marked the pulley to note the offset hole, though when it came off, it fell apart in 3 pieces, so I lost the place. Though looking at the 8 holes on the car, I was able to spot the hole that was a bit further out. The main belt, that was a pain and a half!!! It was a 6PK2334 on my car, the parts shop had a 6PK2330. I did not want to strain any more than I had to, so I got a 6PK2335. It was a real pain, even with that.

Oh and the superchargers idler pulley needs to be loosened a fair bit to get the main belt in behind it. My triple square bit had enough of the hex part protruding from the socket to get a 10mm spanner on it. If you don't have that, pretty impossible to get it on with a ratchet.

The belt took me a couple of hours. Surprisingly the hardest part of it, really twists your brain. I had trouble finding the routing image, so went to the manual. Save you the hassle....https://www.dropbox.com/s/imq2fsogaqilypk/alternator.JPG?dl=0

Any questions or clarifications, feel free to let me know.

[Jake@JHM]

I installed my 207mm in my A6 from underneath