B8 A4 Turbo Replacement

[PaulThBrit]

Hi - I need to replace the turbo/waste gate/exhaust manifold assembly on my B8 due to a leaking wastegate. It has been in the Audi dealer and a local garage and they both diagnosed the same thing. I have decided to do the job myself and have the new assembly and installation kit from ECS and I'm ready to start the job.

There are a great set of step by step instructions in the Audizine B8 A4 DIY: K04 Installation thread on this forum and I posted some questions there a few weeks ago without response so I thought I'd ask here:

1) The instructions in the K04 thread is for those upgrading to a K04 turbo, but I am assuming all the steps are the same as someone just replacing the turbo with an OEM one. Is there another thread or web link detailing the steps? This is the best one I have found so far. https://www.audizine.com/forum/showt...4-Installation

2) Since I am not replacing the cat or down pipe, can I just undo the four turbo to cat bolts and replace the turbo? Is there enough room to get the turbo out? If not can I undo the four turbo to cat nuts and unhook the hangers to drop the exhaust?

3) Do I have to remove the O2 sensor from the cat?

4) From reading this, it seems to be a real PITA if the nuts come off the studs holding the manifold to the block. Any tips there to ensure the studs come out with the nuts? I am guess there is not enough room to get an impact wrench in there and heating the nuts would make the nuts more likely to thread off the studs. Soaking the studs and not the nuts with PB blaster?

5) is there a link to all the torque settings for the bolts during reassembly?

Thanks,

Paul

[Smac770]

erwin.audiusa.com, pay for a day and get the docs for your car. The engine mechanical repair manual tells you all you need to know. There's no need to remove the cat or unthread O2 sensors. Just loosen the clamp, remove the four nuts (sucks a lot more than anything else about this job), and back it up a few inches.

Though when the manual talks about removing the motor mount to create clearance to undo that support bracket, I just laugh at whoever wrote the doc. The thread you reference says what you need to know for that.

As for the studs, maybe one of mine came out. Loosening the plates underneath was simple enough. If those plate nuts are hard to manage, how did you get to that point given the cat nuts and that bastard hex plug on the heat shield?

[PaulThBrit]

Thanks for the tips. I pulled out the turbo/manifold today and got about an hour into the reassembly process. It took me about eight hours to get it out and everything went well. No major problems and the K04 step by step guide that Dan_Q posted here was a BIG help. There are a bunch of tools that I didn't end up using, but it was cheap insurance. Also except one of the manifold studs stayed in the head (nuts screwed off) so that meant I had to take the bottom support rails out to allow the turbo to drop down and then up & out. I then extracted the studs and put the support plate back to make reassembly easier tomorrow.

I undid the rear-most exhaust hanger, the one on the rear of the engine and the one on the rear drivers side. This left one in the middle to support the exhaust and allowed me to push the whole exhaust to the rear so the catalytic converter flange was free of the turbo studs.

I hope tomorrow goes easy and I don't end up with any leaks! I will report back.

Paul

[dkmesa]

how did the rest of your install go?

[PaulThBrit]

Thanks for asking. I wasted a lot of time trying to find lost bolts & nuts, but it all came together in the end. Tip - cover all holes, like the ones in the frame frame that mate with the 'pegs' on the underside of the airbox, with tape! Yes one nut dropped right in there and took a while to recover!.

I had a slight leak on the coolant banjo connection that is against the frame rail. That bolt needs a low profile T-55 wrench. The DIY instructions warned about that and I bought this set which was perfect in removing it. No need for a wrench, I used a ratcheting 10mm box end wrench on the outside. A great addition to the toolbox. https://www.amazon.com/CARBYNE-Piece...gateway&sr=8-2

HOWEVER, I bought the turbo install kit and everything matched up perfectly with the exception of that bolt. It was substituted with one the same size but with an 8mm Allen socket. I was able to use the trick of knocking the hex part out of an 8mm socket and using a 8mm box end wrench on it to tighten it a bit. I have driven 500 miles over the weekend on it and have no appreciable coolant loss so I think it has fixed the leak.

I do have a bad miss under boost so I think I will swap out the coil packs to a spare set I have and check the plugs. Last time that happened a spark plug had 'opened up'. I have never seen that before and wonder if I got a Chinese knock-off NGK plug set when I replaced them about 12,000 miles ago.

This forum is a great resource. It is a good many years since I did a job as complex as replacing the turbo/manifold but the step by step instructions here gave me the confidence to complete the job without major problems.

Paul