Picking up a 2001 TT 6speed Quattro 225 AMU

[Seal1968]

Picking this up for a good deal. Was looking through the Mk1 posts, but this forum seems quite dead sadly. Not my first Audi, I've had 3 A4s...B6, B7 and currently a B8.5, so no stranger to some maintenance.

Ordered some staples: coils, plugs, turbo oil seals, valve cover kit, post cat O2 sensor, new carpet floor mats and cabin filter thus far.

Car has @ 125K miles. Came with coil overs, new cross drilled/slotted rotors, new pads and rebuilt calipers front to back. New tie rod ends, new rear Bilsteins, new/reman front axles, new 17 inch RTX multi spoke wheels + 20mm spacers and a pre cat O2 sensor. Interior is damn good...no rips in seats. Will need speakers...that's a given for these things.

Car is silver, wrapped in gloss black with the small duck bill spoiler wrapped in carbon fibre.

Got a slight oil leak...assuming the valve cover/u-donut seal or turbo oil lines, but will sort that out.

Will post pics when I get things rolling.

Been searching for anyone that has the Audi rotor wheels on their Mk1...want to switch to 18 inch rotors in the spring. Send me your advice gents.

Cheers, Rick

[Spinnetti]

yeah, this forum is surprisingly dead.. Seems like the TT crowd is not DYI/enthusiast minded. My daughter recently got an old TT as a progject.. Needs everything pretty much lol.

[Seal1968]

Well, I'm going to post up some pics....you should document yours as well. I'm sure there will be lurkers that chime in once there's some action.

The B8 A4 forum is quite busy and where I am usually with my other Audi.

[Seal1968]

OK, my first ECS Tuning order arrived.

Valve cover gasket kit, PCV valve, plugs, coils. Moved the secondary air stuff - pulled diverter valve hose, undid all the connectors and flipped aside. Removed the charge tube. Damned 6 mil bolts holding the charge pipe bracket were rusted and rounded. Used a bolt extractor to remove. Snapped one off, the other came loose. What a PITA. Valve cover came off pretty easy...the kit came with the tensioner tool, so dialed that in and took out the 4 torx 30 nuts...that donut was toast...seepage everywhere. Lining up that tensioner gasket was also a pain and I had to remove the bracket on the corner of the head that holds vacuum lines so I could get in there. The gasket came off in 3 pieces...lots of gunk on the back...guess where it was leaking? Cleaned it all up with brake cleaner and a rag.

Put RTV in all 4 corners as recommended...lined her up and dropped the cover back on. Gave the cover a good scrub with a brush and Gunk to clean it up first.

Coil wire plugs need replacing...all are in crappy condition. Had to reuse for the time being, but really folks you can't change them without breaking them? Lots of misfires recorded in VCDS of course. The 2nd ground wire for the coils was not attached and melted...fixed that. Previous owner said he put all new plugs in before I bought her...nope, total BS. They were black and the electrodes were burnt to a fine point. Definitely been in there a while...Densos. Got some NGK coppers for time being. Replaced the coil packs with Beru factory for now as I didn't want to wait for the 2.0 conversion kit.

Replaced the PCV valve (was original) and buttoned her up. All in a couple of hours and a couple of cappuccinos of farting around...the seized charge pipe bracket was the biggest time waster, then lining up the tensioner gasket was 2nd.

Fired her up, ran much smoother, but still a little bit of misfiring...must be the coil plugs as they are toast. Got an intermittent knock sensor code...either connector is dirty or need to replace. Next time.

Took her for a run, and she pulls better...I think I will invest in some new Beru coil plugs shortly as I can't stand CELs.

Almost forgot, removed the CAI and put the factory airbox along with a K & N filter...much better. Not sucking in hot air any more from the engine bay...the kit was a budget CAI...not a fan.

[Seal1968]

Got my order from Wolf Auto Parts...a good used right front wheel arch liner - nothing broken. The one on the car had a big piece missing that protected the intercooler. Also, they also had a great condition TT radio flap which is next on my list to replace. Whomever installed the Pioneer bluetooth single DIN either removed it, or it was broken. Cannot not have one I say.

My order from Crutchfield for all new door and rear speakers came in as well...went with some decent Rockford Fosgates...should be a huge improvement over the old ones which sound awful. Will post up pics once I dive into the doors and rear side panels for replacement.

Waiting on a couple of other bits then I will start replacing all of the coil plugs and tidying up the wiring loom for them. Replaced the cabin filter, and it had a big mouse nest sitting on top - no poop or babies in there so I assume this was a fall thing some little bugger had started. Filter was really gross, so this should definitely help with airflow.

Seems like the new valve cover gaskets have cured the oil leaks...she does smoke a little after you really get on the gas, so I think a piston soak is going to happen soon. These cars tend to have carbon and sludge issues that will clog up the oil rings. I've heard that a soak with Berrymen's B12 has worked wonders for oil burning in the B8 A4s, so I think it could help clean things up a bit.

Picked up a 2001 Passat side mirror switch, so when I replace the speakers I will be doing the switch repair. No knob or toggle at the moment...not on my watch!

Stay tuned for pics once I get everything I need.

[Spinnetti]

Keep it up!

My kid, learning as she goes is doing a good job sprucing up the interior. She replaced the sagging headliner and recovered it in very dark gray fake Alcantara she got off amazon. Looks great! She also did the door tops, and scrubbed everything. We also replaced the shifter bushings with the diesel geeks kit and have a ton of engine and exhaust stuff to attend to. Thankfully, at least the suspension and brakes are in decent shape, but some hack really tore things up in the engine compartment. It runs but I hardly know where to start. The battery just got totally killed too, and won't take a charge even though its not even old. Some drain somewhere.

[Seal1968]

Ya, my engine bay is the same...not a cover to be found lol. Going to get some silicone lines and replace all vacuum lines...maybe try to delete some stuff. The AMU engine appears to have a few more lines with the n75 on top attached to a steel coil cover and another vacuum type do-dad. Might be a check valve or something. There was some sort of amp set up at one point as I found a thick red power line running from the right side just above the airbox (not hooked in...likely went to the box that sits on the battery), and there was some wires left in the hatch area behind the seat. I hate it when people hack the wiring with subs and other junk.

Like you said, the bones are good, so just have to sort through. I sourced a "new to me" 3 way switch for the trunk, fuel and motion alarm that is in the console...the other one had buttons popped apart. I like it when things work as they should.

Totally off topic...I'd love to take a look at your R8. Such a beast of a car. Will post up some pics this weekend hopefully. Try to get this thread going.

[Seal1968]

Today I pulled the original coil plugs off and installed new ones. Pretty easy job once you have the right terminal tool to pop the stay tabs on the wire ends.

They were very brittle and came apart...plugs 2 and 3 were the worst.

#3 literally came apart when I was fiddling with it.

I used black hockey tape as it matches the original loom the best, and it stays together even with heat.

Will clear the codes and see of there's still any misfires.


Original coil plugs.jpg


2.jpg


4.jpg


old plugs.jpg


Done.jpg

[Seal1968]

Hmm...random misfires all 4 cylinders. Wonder if the el-cheapo copper NGKs are the culprit...will pick up some Iridium NGKs and try them.

Otherwise, thinking I might check on the MAF sensor and take another look at the coil loom...may need to strip the factory tape off and re-tape it/clean it up.

Summary...new plugs, new coils and new coil plugs...so should have decent contact. Any other thoughts...anyone? Bueller? lol

[Spinnetti]

Hmm...random misfires all 4 cylinders. Wonder if the el-cheapo copper NGKs are the culprit...will pick up some Iridium NGKs and try them.

Otherwise, thinking I might check on the MAF sensor and take another look at the coil loom...may need to strip the factory tape off and re-tape it/clean it up.

Summary...new plugs, new coils and new coil plugs...so should have decent contact. Any other thoughts...anyone? Bueller? lol

Hmm.. that's odd. Even cheap plugs shouldn't cause that.. dud fake coil packs maybe? I wonder if one of the old wires or grounds broke or cracked making the whole thing dodgy. You might need to replace some of the harness or check a ways in and check ohms. As to plugs, NGK is ok, but Denso Iridiums are my go-to after studying ignition and spark plug design (lame I know, but I really did lol). Another interesting tidbit is the bigger the plug gap, the greater the power, but of course the ignition has to be able to fire it. I ran .044 gap on my stage III+ 1.8T (big turbo up to 30PSI) without issue. I also used the Beru I think RS7 plugs (there were two versions) in my S3 which I also like.

BTW, this is my R8 (https://www.amazon.com/photos/shared...5Y-RicUS8qZht8)

This is my kid working on her TT.. Interior is coming together nice despite all the broken plastic. We are getting lots of plastic welding practice https://www.amazon.com/photos/shared...aQg0Bj0NcVoOGu

[Seal1968]

Ya, thinking the coil loom needs to get looked at. My hands were getting so cold that I didn't bother to dig deeper.

I bought the coils and plugs from ECS Tuning...so my thought is not a quality issue. Will take a look at the plugs and check the gap...see how they look.

Your R8 looks mint! Not many manuals out there. I heard the earlier ones have a potential front upper suspension flaw with the aluminum arm...it tends to get weak and crack. I saw a guy do a weld repair on Youtube for $500...Audi wanted $10K+ lol. Assume you'd already be aware of that. What a beauty though.

Your daughter's car does look quite clean too...good to see her take interest. My boys are the same, they dive in and DIY too. That way they appreciate their vehicles with some sweat equity. My youngest has a mint 2000 Silverado 4x4 and the older one has a 2021 WRX that he bought new...he's the 3rd year apprentice mechanic. His WRX is tuned to 350 with stage 2. It will smoke my A4.

[Spinnetti]

My A4/1.8 made over 350.... and my S3 over 400 - My S3 was quicker 0-60 than the R8. Bring over the soob lol... (I've had a couple old soobs too)... The R8 frame cracking is both real and kind of an old wives tale. Yes, you can crack it but you'd have to really work at it. You can buy the Audi reinforcement parts online for like $100 from europe and tig/mig weld them in (easy enough - just need to remove enough interior to not set it on fire), but I didn't see any reason to do it and there's no way to re - heat treat/passivate the weld area, so I think it does more harm than good. I wouldn't let that worry me. The only "weak" points are the lifespan of the magride shocks (I'm thinking of putting Ohlins on next year) and the AC compressor is a bear of a job to do. Pretty minor stuff. If people can afford the car, a couple grand for non-routine repairs should be part of the purchase equation.

[Seal1968]

I'm thinking of a S3 to replace the A4...but it's hard to let go of a manual. Not many B 8.5s out there with 6 speed...

Ya, it's amazing how much hype a small issue can become over internet forums, re: R8 cracking suspension of death.

When I bought my Boxster S it made me paranoid that the engine was a ticking time bomb. Car proved me wrong and was super reliable and I had zero issues. I kind of miss it as it was a fun car, but it turns out I'm not a convertible guy...coupes for me.

Here's my A4 and Boxster.

picture.jpg

2001 Boxster S.jpg

[Spinnetti]

Same here, I'm a coupe/manual guy. funny about IMS.. that scared me off Porsche lol... I guess similar thing. I ultimately sold my S3 for not being a manual.. it was pretty awesome otherwise.

[Seal1968]

I looked at a new S3...but I hate what they did in 2021 to the gear shifter...at least the 2020 and earlier have a shifter that looks like a shifter. The knob looks silly. If I ever buy one, the newest year is 2020 for me. Maybe I'm old and cranky?

The TT/TTS still have the nice shifter, great bang for the buck...I priced a Cayman S and dollar for dollar/performance-wise the TTS is a great deal. Only thing is, the Cayman comes with a manual, which I prefer. Not sure I'm ready for an automatic just yet...still got lead in the pencil lol.

Getting back to the TT...my son brought home his Snap On scanner to see if it could pick up anything VCDS missed. Random misfires cylinders 1, 3, and 4. He reset the throttle body in case it learned something from the crappy cold air intake it had...doubt that'll do anything, but the codes have cleared and didn't come back while idling for a half hour or so. They popped back shortly after I had cleared them with VCDS previously. We shall see, probably a placebo affect. I'm thinking possibly injectors are dirty, so may check on that and also the wire loom as I should have taken the time while I was changing the coil plugs. I'd think cylinders all would be misfiring if it was the loom, but you know how electrical gremlins can be. Stay tuned.

[Spinnetti]

Oh, I didn't ask, but random misfires on all engines is normal. Question is how many - as long as its not throwing codes is probably ok.

[Seal1968]

No, it's throwing the CEL and slowly driving me nuts. Will be diving in this weekend to investigate.

Might see if I can debulk the bird's nest n75 set up too, and replace some vacuum lines...what a mess. I'm sure everything is original and it's really hard to track down leaks with the old tubing, especially the stuff with fabric covering. Damn German engineers lol.

ps...I picked up some Denso iridiums too...thanks for the tip.

[Spinnetti]

No, it's throwing the CEL and slowly driving me nuts. Will be diving in this weekend to investigate.

Might see if I can debulk the bird's nest n75 set up too, and replace some vacuum lines...what a mess. I'm sure everything is original and it's really hard to track down leaks with the old tubing, especially the stuff with fabric covering. Damn German engineers lol.

ps...I picked up some Denso iridiums too...thanks for the tip.

Nice. any luck? We've got the birds nest of vac leaks to deal with too. I ripped all that stuff out on my A4 but that was 20 years ago, so have to re-learn it. I probably still have posts on it on Audiworld and here lol.

[Seal1968]

No, we had a winter storm and got over 2 feet Saturday night...winter is finally here, so I got distracted by snow blowing and shoveling. I did order a few parts from Uro Tuning and a local source for silicone vacuum lines...got 4 and 6 mm to start tidying things up. Lines are all original, and I'm 99.9% sure there's some leaks especially under the intake manifold. I remember deleting some stuff on my 2005 B6 1.8...will do the same here and clean up the engine bay. I'm starting to get excited about the project and proving I can get this running the way I want it to.

[Spinnetti]

Maybe I'll be lazy and just do what you did when you have it going lol.. I know there's stuff here somewhere on what can get removed and what routes where.

[Seal1968]

OK, got some nice new parts to tackle the vacuum lines and n249 crap. Not sure I'll get to the pipes under the intake, but definitely get the n249 delete and run so me new lines along with a new DV.
Today's parts...hopefully.jpg

Pulled all the old crap out...geez it was botched together with the one line to the boost solenoid.

Old junk.jpg

Plugged in the n249 delete resistor and secured it.
n249 delete rsistor.jpg

Removed the front plastic cover and plate that holds the dipstick, traced the two main lines. One gets capped at the solenoid that attaches to the plate, the other goes onto the intake, then up to the DV. Back starting to hurt crouching over...not sure I'll tackle the suction pump and new assembly I bought today. Anyway, ran the new lines.
New vac line to DV and intake.jpg

Sure cleans up the top of the engine. I fired it up, no vacuum leaks.
Much cleaner.jpg

Now for a cappuccino...then back out to look at the coil wire loom to track down the misfires. Stay tuned!

[Seal1968]

PS...re-ran the smaller line from the charge pipe to the boost solenoid...didn't like that it looked kind of messy. OK...I'll pop some tylenol and get back at the coil wire loom.

[Seal1968]

OK...peeled/cut/repeat. By some weird miracle I didn't slice my hands up...'twas a first for sure.

Pulled all electrical tape off right to the far right edge...lots of "breaks" in the wire covering all throughout. Taped each break, the re-wrapped it all and went for a spirited drive. (by spirited I mean redline every gear...no better or fun way IMO)

Some misfires at idle, but really pulls hard now. The new boost control solenoid, diverter valve, and the new vacuum lines must have helped her out.

Thinking I really need to suck it up and get replacing the piping under the intake with the suction pump, etc. I found the main piece at Uro Tuning for under $70 which I thought was a steal.

Stay tuned.

[Seal1968]

Did some poking around and it looks like there's some cracks/tears in the pipes that connect to the suction pump/intake, etc. I think this is the probable cause for the misfires methinks. I'm gathering a few hoses and I have most parts ready to clean this up. Guess what I'm doing this weekend? lol

Stay tuned if anyone else is following. It's sure damn quiet in this forum.

[Spinnetti]

yeah, totally dead. Maybe tt people don't work on their own cars... Will mess up their nails lol. A4 forum at least used to have a lot more activity - same engines, so maybe a better hangout.

[Seal1968]

You might be onto something...when I had my B6 there was lots of activity. If I run into problems, that's where I'll be heading. I do see one fella asking about the Haldex here but I can't offer much help as I don't know much about it, other than you need to change the oil and filter back there every 100K or so.

ps...you'll definitely mess up your nails when you work on the PCV system under the intake! lol

[Spinnetti]

You might be onto something...when I had my B6 there was lots of activity. If I run into problems, that's where I'll be heading. I do see one fella asking about the Haldex here but I can't offer much help as I don't know much about it, other than you need to change the oil and filter back there every 100K or so.

ps...you'll definitely mess up your nails when you work on the PCV system under the intake! lol

lol... see you in the B6 forums.. that's where I used to hang out too - had my B6 14 years but sold that in 2015.

[Seal1968]

Alrighty then...I pulled out the old PCV tubing...suction jet pump, all tubing. Goddamn single-use hose clamps - what were they thinking? Replaced all, ran new lines for fuel pressure regulator and combi valve. Installing the new tubing was much easier...old stuff is just plastic, the new stuff I bought is more robust with metal covered in plastic.

Holy crap my hands are sore from trying to wedge them under the intake and work the tubing out. You sure can see the sludge buildup in the PCV pipes, that is for sure.

Fired right up, no vacuum leaks. BUT...I still have some misfires at idle.

Going to look at the fuel injectors and fuel pressure regulator next. At least that is a relatively simple job...will look through the B6 forums too. Now where's my damn beer...

[Seal1968]

Ordered a new fuel pressure regulator as it was cheap, and the current one is old. Injectors are firing OK by sound/touch. When you unplug each coil as it runs the engine misfires more, so they appear to be running OK. Scanned VCDS again...got some new codes...the N249 delete resistor must NOT work as prescribed...secondary air flow error. Now there's a MAF sensor flow error/intermittent. Will unplug when running to see if that improves. May reconnect the N249 with all new vacuum lines to see what happens as it's an easy fix. Stay tuned!

[Seal1968]

OK...I reconnected the N249 with new vacuum lines, cleaned the MAF sensor with some CRC aerosol and replaced the fuel pressure regulator. The FPR had some gunk on all of the screens, possibly impeding the flow. I fired her up, and the misfires are greatly reduced. She boosts up properly when getting on the throttle.

When I took the intake boot off at the throttle body I noticed a lot of sludge in there...so I ran a can of CRC through. She smoked like crazy...some improvement to idle. Will grab another can and repeat...I think there's a lot of gunk in the intake. More to come.

[Spinnetti]

We'll probably have to do the same stuff... If you pull your intercooler hose off, I bet oil pours out of that too.... might be good to rinse that through as well.

[Seal1968]

Oh ya, full of sludge. Still have misfires. My son is bringing his compression test kit home for me this weekend. Going to do an engine flush and piston soak at the same time...really give her a rising out lol.

After looking around I also found a new coil wire loom kit...from plug ends right to ECU for @ $170 CAN. Pretty cheap, IMO so I might pick it up.

I bastardized the existing coil loom and added a common ground for all 4 coils to the valve cover, as I know grounding issues plague these cars. No change.

Will get a voltmeter on the 12V to see what's what I think before I dive in and do a full swap.

Wondering about the fuel injectors now as well...firing, but if the pressure is shit it will misfire. Now where's my parts cannon and visa? lol

[Seal1968]

Piston soak in progress...will rotate the engine every few hours for shits and gigs, although not sure if that helps. I am using Berryman's B12 Chemtool as I've heard it does a great job cleaning up coked up oil rings on the E888's. Stay tuned.

[Seal1968]

OK, soak completed...no fluids in the cylinders when I cranked it so the B12 must have seeped its way into the crankcase.

Rebuilt the N249 with a new valve body and all new vacuum lines...re-oriented it and it's much tidier.

Turned the key on, the check engine light was not on...was the N249 the culprit? Tried to fire it, but now the fuel pump doesn't prime. WTF?!

Sonofabitch. This is new.

Pulled the rear seat out, took the access cover off and sure enough pump doesn't seem to be working. Tapped it with a screwdriver and turned the ignition on, nothing. (seeing of it was "stuck")

Fuse OK....now wondering if the relay is stuck closed. Ordered a relay since its cheap...created a few new swear words today.

Stay tuned...will post up pics of the refreshed N249 shortly.

Again...sonofaboitch this is frustrating.

[SkillzVrt]

Do you have access to Vagcom ? I've been dealing with similar issues for 2 years now and finally gave up . Going to start working on it again.

[Seal1968]

Turns out fuse #10 was blown (a mini fuse)...replaced it, and she fired right up. Now I have a spare fuel pump relay...not a bad thing as relays can fail over time. Geez

[GvB6a46sd]

Hey, when I got my B6 Avant, the mechanic who put the used motor in, said the coil pack harness was a known issue and replaced mine with a 034 part. This looks exsactly the same.
https://www.ecstuning.com/b-ecs-part...012211ecs01~a/

Good luck!

[Spinnetti]

Wow, you are really going the extra miles... a single leaky injector will make it run crummy, especially at idle. IIRC they are pretty cheap for a fresh set, but all that other work you are doing isn't wasted and good maintenance regardless of final root cause(s)

[Seal1968]

I hear ya...will get back at it this weekend. Might look at the loom again and do some voltmeter testing...maybe pull the injectors and take a look at them. ECS has the set of greens for $195 USD which is pretty reasonable for 400 CC injectors. I think I've seen them for @ $96 CAN each here as well. Once I get the misfiring sorted I'll feel much better.

[Portlandareae28]

chiming in! There are at least 3 of us paying attention to this thread. I am just starting the process of bringing a built 2.0 stroker B5 A4 back down to a gentleman’s fun daily sedan. And with refinement and reliability being 2 high priorities, will be doing the same things you are doing here. I bought this car to play with, with my son after he bought himself a b5 a4. As a VW kid I remember looking at brand new B5’s in the showroom but of course way too much money. He found me this car that was definitely built to go fast without much refinement in mind if you ask me. I bought it for the extremely cleanliness, paint is great, clean interior, etc. Anyway, like the MK1 TT’s the B5 A4 i think still flies under the radar. I paid next to nothing for this car that is 4cyl turbo, awd, manual transmission, has a sport cloth interior, etc. and super easy to work on. TT is definitely on my bucket list, wondering if the DSG could be put behind the 225/1.8 then maybe a fuel pump, injectors, and e85 tune and I think it’s in the high 200’s crank hp…. Anyway, i vote to keep this thread going and I look forward to seeing what you find for the misfire.


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