Replacing Intake Manifold and Removing Carbon Buildup - 2.0TSI

[planehazza]

Job's complete, eventually... Taking the IM off, fitting all the bits to the new IM, cleaning the valves, ports, and TB, and then fitting it all back together.... took me about 20 hours in total, maybe more!  It is a right horrible job to do, but it was very necessary.  Annoyingly, it hasn't cured my warm idle engine twitching, but the throttle response and acceleration have improved from what I can tell.  Never had it on a rolling road so have no stats to compare, but it definitely seems better so far. I was getting intermittent p2015 errors indicating a fault with the IM. It never brought up a dash light, but I knew that the carbon buildup would be an issue with the car having 70k, so I coughed up £130 and bought a new IM from the US and replaced it whilst I had it off to clean the carbon.
 
Apologies as I'd set off to document the process and do a write up, but it quickly became a bit of a nightmare and took twice as long as I expected. Having said that, I'm glad I did it and am proud that the novice that I am managed to do it without breaking anything or making any serious mistakes.  I can only really thank this forum and its members for the help and advice I get daily 
 
 
Things to note:

• The bracket under the IM is a git to remove and get back on.  I could only do it by taking the throttle body off the IM.  To do that you'll need to remove the intake breather pipe from the front that runs down to the radiator. Two T30 captive bolts hold it on. You'll need a 10mm Triple  Square, which I didn't realise I didn't have until I'd taken half of the engine bay apart.  I cheated and used a t50 torx which damaged the head of the bolt, so I'd only say do this if you literally have no choice like in my case.
   
• That breather pipe is a git to remove and get back on.  It took a good hour of messing around and fiddling. There is no room for wiggling, but there seems to be a magic angle, which out of the blue, I seemed to get and it slotted straight in. Make sure you connect the sensor before tightening up the two t30 bolts as the clearance for the sensor connector is minimal.
   
• The TB is also a git to remove and get back on.  Only 4 self tapping t30, but getting a tool in from above or from under the car is a nightmare - there just simple is no room to get a ratchet in and the angles are horrific.  It would have been a lot easier I think if my extensions bars were rigid and not wobble bars, but alas I didn't have any...
   
• Spotting the pattern here? Most things in this job were gits to remove and reinstall....
   
• Picks! You'll want little picks of different styles. You will not get all of the carbon desposits from the valves/ports without them, no matter how hard you try.  I started by scratching the dry carbon gunk off with a flat screwdriver, and blasting the bits out with an air duster, making sure to catch it in a towel.  Make sure the valves you're working on are closed, and that all others are block with rags.  Also, make sure the injector holes (if they come out with the IM - all 4 did for me!) are blocked - you really don't want this crud dropping into the chambers!
   
• Seafoam...  Totally overrated IMO.  I found Wynn's Carb and Injector Cleaner to work much better. Once the main chunks of carbon were picked off with a flatblade and picks, I flooded the ports with carb cleaner and let it sit for 10 mins or so. With the carb cleaner still in, I attacked it again with picks and a brass bottle brush by hand before extracting the fluid/gunk with a hand pump.  I put more carb cleaner in then attacked it with fresh brass brush in a drill. Sounds very harsh, but it'd be very difficult to do damage in here - just don't do anything stupid or jam things in hard and you'll be fine.  Once the thick stuff is off, it cleans up surprisingly well (see photos).
   
• Take photos! There are a lot of connectors. The loom is done in a way that connectors can only really go back where they came from, but you'll be disconnecting a good 15 sensors/connectors to get in and remove the parts, so make sure they all go back!
   
• Be prepared for stripped bolts. Two T30 bolt holes in the head for the IM lost their threads when I took the bolts out.  Previous owners/mechanics obviously had the IM out at some point and overtightened them putting them back in.  I was very careful putting them in (worked with RC helicopters for a decade so used to not over tightening bolts) making sure not to cross-thread them.  I had no choice just to put them back in so right now, my IM has two bolts that are nowhere near as tight/secure as they should be.
   
• You'll need new fuel injector seal kits at about £8.50 each.  Buy four, maybe even 5 so you have spare.  The teflon seals are not hard to fit, but you need a specialist VW tool to do so and you only get one attempt.  If you warp or damage that seal, scrap it and try again, otherwise you'll get a lovely 1500psi fuel leak. On the subject, make sure you clean the injector nozzles whilst they're out.  I used seafoam and a clean, lint free rag as well as soft brush.
   
• When you refit the IM, make sure the injectors are all plugged in, and that you push down on the wiring harness so the IM can slide back into place. If you forget, it’ll all have to come off again as you’ll not get your hands in afterwards!

Dirty, gunky valves:

 

 
 
Clean valves:

 

 
 
Dirty injector nozzle:

 
 
Clean TB:

 
Full album: https://goo.gl/photos/ec63eR38mcS72w3x5[/size]
 
These videos are very helpful:

 
VW T10133C Tool:
This is not cheap at about £150, but I got it used off ebay for about half that. There are clones out there for about £35 but given the tight, precise tolerances, I personally wouldn't use anything other than the official tool.  If you need to use it, give me a shout and I'd be happy to lend it out.

 
I'm sure I'll think of more to add, but if you have any questions, give me a shout and I'll do my best to help.  
 
Thanks for reading! Edited 26 April, 2016 by planehazza

[TheClient]

Thanks for the write up. Lot's of good tips there. It does sound fiddly. Obviously a job to carry out over a few days! Your valves and TB look tremendously clean from my review of the photos.

 

When you say "picks" - what did you actually use, unless you're a dentist?

 

And what did you do about valves that were not fully closed.  Did you turn the motor on the starter to rotate after finishing all the other ports with closed valves? 

[sparky2]

I wouldn't turn it over on the starter, it would be much better to remove the plugs and turn the engine on the crankshaft inserting a plug in the cylinder you want to work on and turn it until you feel compression and that would show that the valves are closed in that one cylinder ! cheers Stuart

[david2vRS]

Any idea how much a job like this would cost at an Indy?

 

Need to have it done asap and i'm very concerned about the potential bill 

 

Cheers

[planehazza]

Any idea how much a job like this would cost at an Indy?

 

Need to have it done asap and i'm very concerned about the potential bill 

 

Cheers

 

I was quoted about £650 to have the IM replaced and valves cleaned, but I can't see it being a thorough job for that price.  The VAG price of the IM is about £350 alone, and it's a good 4 hours labour to replace that without considering the valve cleaning.

[planehazza]

Thanks for the write up. Lot's of good tips there. It does sound fiddly. Obviously a job to carry out over a few days! Your valves and TB look tremendously clean from my review of the photos.

 

When you say "picks" - what did you actually use, unless you're a dentist?

 

And what did you do about valves that were not fully closed.  Did you turn the motor on the starter to rotate after finishing all the other ports with closed valves? 

 

Sorry mate, never saw these replies for some reason.  Just a metal pick set from a DIY shop.  Cost like a fiver.  The valves are very hard and even surface/cosmetic  scratches to the backs of them isn't really a problem.

 

To turn it over, I left the car in third or fourth and jacked up one side. I just turned the wheel by hand until #4 closed. I was very lucky in that when I took the IM off, cylinder 1, 2, and 3 were all closed.

[TheClient]

Not to worry, haven't needed it yet, so a late reply is still a worthwhile reply!

[planehazza]

Not to worry, haven't needed it yet, so a late reply is still a worthwhile reply!

Let me know when you attempt it.  I have the official VW injector tool that you'll need.

[david2vRS]

Still haven't had this done, engine management light has gone out and car seems to be running fine.

 

Going to get a few quotes in the new year and see what the damage is.

 

Anyone ever tried one of these mobile carbon cleaning services?? http://www.enginecarbonclean.com/ 

 

Are they any good? will they buy me a bit more time before i do the job properly?

[planehazza]

Still haven't had this done, engine management light has gone out and car seems to be running fine.

 

Going to get a few quotes in the new year and see what the damage is.

 

Anyone ever tried one of these mobile carbon cleaning services?? http://www.enginecarbonclean.com/ 

 

Are they any good? will they buy me a bit more time before i do the job properly?

 

I guess how successful that works depends on how gunky you car is.  As an example, look at my images above to see how bad mine was at ~70k.  Personally, I would NOT want that going into my engine.   I was quoted around £700 to have the IM replaced and the buildup removed whilst the IM was off.  In hindsight, it wasn't a bad price and I may have looked at paying it had I known just how much work was involved in the whole process of doing it myself.  Still though, I'm glad I tackled it and I learned a lot in the process.  If I can do it, the majority on here can also :)

 

Get a cheap borescope and visually inspect the backs of the valves.  It will tell you how bad it is and whether cleaning is necessary.

[david2vRS]

I guess how successful that works depends on how gunky you car is.  As an example, look at my images above to see how bad mine was at ~70k.  Personally, I would NOT want that going into my engine.   I was quoted around £700 to have the IM replaced and the buildup removed whilst the IM was off.  In hindsight, it wasn't a bad price and I may have looked at paying it had I known just how much work was involved in the whole process of doing it myself.  Still though, I'm glad I tackled it and I learned a lot in the process.  If I can do it, the majority on here can also :)

 

Get a cheap borescope and visually inspect the backs of the valves.  It will tell you how bad it is and whether cleaning is necessary.

 

Cheers for the information planehazza, much appreciated.

 

I have a borescope in work so ill borrow that and have a look!

[BristolBikerMan]

Great write up. Will be using this to replace four injectors this week.

[d33p]

Obviously its better if a build up of gunk is not there at all, but does it actually hurt performance?

My last Octy was a 2.0TFSI and had 175k on it (before she was unfortunately written off after someone pulled out across me) and it ran perfectly. It occasionally had the twitchy tickover which I hear is common on VAG petrol engines, but it never felt down on power. In fact my new (to me) 2017 vRS 230 doesn't really feel any punchier than my old vRS.

Just curious what damage can occur the carbon build up, and if its something I should be worried about with my new Octy.