DIY removal of intake, carbon cleaning, injectors, water pump, oil cooler, accessory bracket

[YamR1rider]

Did the above this week on our 143k miles 1.8 TSi, reasons being random EPC lights once every week or two and as described by daughter, 'shuddering', aka misfires/EPC light+limp mode (OBDEleven said 'cylinder pressure to high' and resultant 'hide cylider', plus very occasional (once per 2-3 months say) temperature shooting all the way into the red and resultant EPC/limp mode/pull over now etc (OBDEleven 'poor coolant flow'). And one time apparently, 'very limp' mode where there car would barely move off a traffic light.

Yet in all cases, a quick turn off/on would clear all and car would run fine, misfires gone, temps instantly normal ....until the next time which could be days to weeks away. Plus there was an oil leak which seemed to be coming from the cooler and a slight internal cooler leak (tiny amount of oil in coolant).

Goes without saying I'd already done the routine easy stuff like plugs, coils, injector cleaner etc. So, I decided to 'parts cannon' it,'while I'm in there' style.....thankfully, no 'labor cannon' required, DIYed the lot. Didn't find it *too* bad of a job....but there were some curse worthy moments and bolt battles encountered. In summary, for anyone having a go at similar in future:

1. Manifold off - really not that big of a deal. Worst of it for me was paranoia of breaking the six-eight electrical connectors to be disconnected, which after 8 years, were fused together and the plastic brittle and nasty. Silicone spray, patience and research into how each different connector locking mechanism works helps. Only one real casualty - cam sensor - just crumbled in my hands the plastic was so rotten. Hadn't counted on needing a new one and could have probably taped/glued the break back together somehow....but managed to get one locally (from autozone) so didn't hold job up too much and as much as I'd have preferred an OEM one, this 'duralast' seems to be fine. Other mildly tricky bits with the manifold included the front bracket with its hard to get at M10 triplesquare, and separately, the bottom hard fuel line to fuel rail nut - needed to cut a cheap harbor freight 17mm in half to get that off. *Note anyone watching humble mechanics way of doing it (which is otherwise excellent as he really removes the minimum amount of stuff to get the manifold off...others like FCP Euro...while they sure are comprehensive, I thought they were going to start stripping the cylinder head, ,maybe remove the engine entirely while they were at it lol), "get the manifold off without removing the hard fuel line first, or conversely put the hard line on before the manifold" - nope - that could only potentially work on later Mk7.5s like his yellow R (or my own 2017 GTI) where they seemingly changed out the two top outer manifold studs and nuts to bolts which will give some left to right adjustment of the manifold. Otherwise, the hard fuel line must come off first and go back on last. What you could do, while you are at it, is replace the nut/studs for bolts like the later cars to make the job easier in future.

Manifold off... fairly simple tbh

Tool of champions

2. DIY carbon cleaning - If you don't walnut blast its never going to be immaculate but I found that closing the valves, flooding with carb cleaner and going at it with a fistful of cable ties makes it a lot better than it was. Quick note, I'd recommend you cut the smooth tapered ends off the cable ties as they have a tendency to break off. I blew a broken-off end out with my compressed air....but best not one go unnoticed and then drop down into the cylinder when you rotate the crank for the next one. Otherwise, jabbing away with the ties is pretty much risk free and combined with carb cleaner, does loosen up plenty of crap....then hold a rag over and blow out with compressed air at the end. Rinse/repeat at least three times....I should have have a couple more go rounds//let soak longer really, but hey, they ended up much better than before!

Pretty gunked up...perhaps not as bad as could have been....no idea if they have ever been done before or not

Pic doesn't really do it justice, I think I took this after 2 go rounds but much improved. Time and extra scraping would have helped but I wanted to crack on with the below....

3. Injector replacement - bought OEM Bosch ones from FCP Euro, saved a lot over branded VW for same thing. Even though new injectors come with seals....make sure you do spend the extra 9 bucks per cylinder on the fitting kits. The new injectors don't come with the 'hold off/ injector bore spacers' (or whatever they are called...little plastic rings with three prongs them), nor the metal top tension rings. You could reuse these parts....but in my case one of the 'bore spacers' broke on removal so I was happy to have the new ones on hand, plus the top tension rings - you don't know if the oldun's have become over compressed. That all said, replacing the injectors was the easiest part of this job. When I pulled the fuel rail, 3 came out along with the rail, and the last one came out with minimal pick/by hand persuasion, no $100 fancy slide hammer kit required. New ones pushed in by hand and wiggling, no hassles.

Pretty sure these were original 140k mile injectors. Pretty carboned. My moneys on one or more of these (rather than the grubby valves) for the intermittent faults

Old injectors as they came out. Note the broken 'pronged bore spacer thing' just above the top right one. A prong broke off when removed the spacer from the injector, very fragile/brittle plastic, hence why I'd recommend having the fitting kits on hand rather than trying to reuse those parts.

4. Water Pump - The one coming off this car was the original (2014 date stamp)...amazing eh, its done 140k...and wasn't actually leaking!!, Only reason I took it off was due to the dodgy temperature control actuator, (as I understand it, this is built into the waterpump /tstat module, there are also temperature sensors on the transmission side of the cylinder head and one down on the bottom coolant hose...if it turns out the be the other ones so be it (pretty easy fixes both) but I couldn't do all this work and leave this old pump in there!). It was a G revision. As replacement, I bought an INA OEM (VW/Audi logo scrubbed off) from FCP Euro. A massive pain in the ass for this job was getting off the T30s holding the drive belt cover....in hindsight and if doing it again, I will take off another couple of coolant pipes off as its blind and so very tight to get just a socket in, let alone a ratchet. Cue skinned and bruised knuckles, and scratched/minor cut fingers galore. Same goes for the bottom two water pump bolts....blind and horrible, you just have to persevere and try lots of different length 1/4 extensions etc. (you could take the fan housing out I guess which would give a bit more room....but to me that looked like even more hassle with more breaky clips, so didn't bother). Also on replacement, very very carefully watch the union that goes between pump and oil cooler...it has a tendency to pop out and twist sideways slightly......my huge mistake on this entire job was thinking it was in straight when it wasn't. Was alerted to this fact when I went to refill coolant (using my vacuum filler, wouldn't hold pressure..... I did get some water in though and sure enough, there found the union leaking. And thus.....had to deal with taking the f@@king pump off and on again. Plus the infernal waterpump drive cover bolts. Faster second time round, but this was not a happy time!!

Cracked this old thing apart for fun....8 year old 140k+ miles no leaks...who knows maybe its not even this sensor that's the cause of this issue....but while in there it had to go. RIP rare 8 year old/no leaks MQB water pump....a rare breed indeed!

5. Oil Cooler - with water pump off, not too difficult to get at the four bolts and take off. Mine had slight internal leak and larger external leak. Clearly the issue was the old brittle seal - but while there I replaced the cooler with a pattern UroParts one - took a bit of a chance here (where I'd never do with critical components such as injectors or water pump).....but its not a complex component for the aftermarket, and seems perfectly fine. Original also seemed fine after 140k miles to be fair - Think I will clean it up, run some de-gunker through it and keep it for a spare. Leak fixed, happy days.....at least...I think. If in the coming days it transpires there is still some leakage, next up will be to unmount alternator and a/c compressor then pull the oil filter housing bracket to get at the other back-side seal. At least that bit will be doable without taking manifold back off etc. should it come to it.

Been leaking a while this one

Nice fresh seal

6. Conclusion - Despite some tribulations, got it all back together....car cranked a bit longer than usual first time as fuel was priming through but then struck up nicely.....and the car is running beautifully - so super happy.... as of 19 Feb have even given it the berries up and down a favorite bit of 'track' several times, super smooth the entire rev range!

Next up at some point will be to refresh the worn shocks/struts which are also probably 140k originals too....its in perma 'super comfort/sofa mode' just now lol!

 

[YamR1rider]

OK...so while I think changing the oil cooler gasket as mentioned above fixed my oil leak problems....I had a nagging doubt I'd only done half a job, as there is another gasket behind the Oil filter/Alternator/AC compressor bracket. So to put a finishing touch on this whole saga, today I decided to sort that one out, pics below. Couple of cliff notes:

* If you only have a leaky oil cooler to deal with, this is the way to do, its a little bit less hassle vs accessing via manifold off/remove waterpump first route. Plus, you would get to do both seals (oil cooler to bracket, bracket to engine) at the same time. If you do however have manifold off for other work....in hindsight this would be a bit easier to do right there and then as you will have more and easier access from the top (but by no means essential).

* Getting the oil cooler-waterpump union in right when replacing the bracket was again a bit of an exercise in patience and frustration. Highly recommend when you have it in place (or think you do), bolt up the bracket and then before you go any further, pull a vacuum on your cooling system just to make sure you've got it (make sure all your other hoses are on right too) before you bolt your alternator and ac compressor back up. Mine was fine first time round this time, but I'd hate to bolt everything else back up just to find its leaking. When reinstalling the bracket, its a good idea to remove your oil filter to gain some more wiggle room as you have to angle it in just right.

* More breaky-clips to remove with this job...three under the oil filter housing, one on the back of the alternator (plus another power strap held by a 13mm nut under a pry off plastic cover), one on ac compressor (although its arguable you actually need to remove this one if you just let the compressor sit on the charge pipe below it). Silicone spray and patience are again your friends. I had no casualties this time.

To get at the bracket bolts you have to remove the alternator and swing the ac compressor out the way - not too difficult as the bolts on both fairly accessible (alternator from top, ac compressor from bottom).

Bracket is mounted with 5 bolts, again not too tricky to get to, and then you can remove bracket upwards. Old gasket was nasty and brittle, as expected.

View of engine with bracket removed

New seal in

Yet again, aligning this thing was the biggest pain in the ass for the whole job

 

[odessa.filez]

I really appreciate your thread. I'll be there someday

 

[xabhax]

If you replace the two studs with bolts you no longer have to loosen/remove the fuel line.

 

[YamR1rider]

If you replace the two studs with bolts you no longer have to loosen/remove the fuel line.

Yeah, as I was thinking...thanks for confirming. Out of curiosity just had a quick look at my 2017 GTI, it's got the bolts in those end holes (rather than nut/studs) from the factory. My daughter's car is a 2015.... I guess VW learned the error of its ways with the stud/nuts sometime in between.

 

[FamilieTrukvagen]

I want to thank the OP. I also followed Charles' video for an injector swap on my 2015 and got stuck on that fuel line. I finally was able to loosen it with an 18mm crow's foot. On the reinstall I replaced the studs with bolts (hex head M6-1.0 x 45mm) and it went in much easier. The access holes in the manifold to access the lower manifold bolts were too small for my 3/8 T30 socket so I had to pick up a 1/4 version. That triple ten bolt for the lower bracket is also very hard to get to, at least from above. As troublesome as DGI can be, both for valve crud and injectors, VW did not make them easy to service. Very frustrating.

 

[YamR1rider]

Thanks, pleased it was of some use! Yep those lower manifold bolts can be tricky....I had one get caught up as I was pulling my magnet, dropped down somewhere never to be seen again, had to get a replacement. And agreed on the lower bracket triplesquare. As and when I take the manifold off again, I wonder if its possible to get it started very loosely first then get the manifold seated on the top stud afterwards. As you have done, replacing the outer studs on the manifold to engine with bolts (or if you have a later car that comes that way) might make it doable.

Plenty of awkward moments for sure....but I don't think VW/Germans are alone in that these days. I had a look at a neighbors new accord with the 1.5T engine - looks equally tight and tricky in there too.

 

[BudgetPhoenix]

Nice pics. I've done that accessory bracket job on a gen 1 TSI. Not a fun one to do! My leak was the gasket that goes against the block, it was super brittle.

 

[Goodbar]

Thanks for the writeup! I'm preparing to replace the water pump and thermostat and am considering a parts cannon approach (great term!), to include the oil cooler gasket.

Anyone have the PN for the oil cooler bolts? The repair manual shows that they are single use, but they aren't listed on the VW parts diagram:
https://parts.vw.com/a/Volkswagen_2...archGuid=76F629EA-F1C4-4B5E-B725-C33CBDDBBFE4

Thanks.

 

[YamR1rider]

Hi @Goodbar - must admit, I reused mine, was just careful when tightening them back up; a small dab of blue loctite and then I think I went to the 8nm and gave them just a bit of a tweak after that (but probably not the full 45 degrees to account for the possibility they are already stretched'). Did the additional tweak by feel; they are plenty tight. Same with the accessory bracket ones - they are also one time use but again reused with no issues.

Always find it a bit odd with the low torque one time bolts - I can see the logic in replacing things like the rear caliper carrier bolts with their massive amounts of torque, but have yet to have an issue with reusing the low torque items. Another case in point are all the oil pan bolts; they are also supposed to be one-time use but I think most people (including me) just reuse them. Touch wood I've have no trouble so far...but with decades of home mechanicing (to include the misery of stripping some in my younger days!!) I've developed a fairly good feel for bolt tightness.

If you do want to do it by the book however, I believe its these: https://parts.vw.com/p/Volkswagen__GTI/Bolt-Oil-Cooler-Screw-Upper/48724403/N91048802.html . For the life of me I cannot now remember if all four bolts are the same length but I *think* they are.

Let us know how you get on with your jobs! If you are going to do that side oil cooler seal as preventative maintenance (must admit, I probably wouldn't if there were no problems), also consider doing the rear accessory bracket to block one while you are at it (and thus take advantage of the extra working space while your manifold is off). As I mentioned though, you can pull the bracket without the taking the manifold/waterpump off in future should an issue develop without too many problems (albeit it is somewhat tight working).

How many miles do you have on your car?

 

[Goodbar]

Thanks for the info @YamR1rider. The two gaskets (Elring equivalents) and oil cooler bolts were about $12 total, so I decided to order them and make a game-day decision as to whether to replace. But leaning toward keeping them on the shelf and replace if I get a leak later, per your guidance.

The car has 83k on it. We bought it with very high miles (68k in 2021), but only drive it about 6k miles/yr. That was was my "strategy" to lessen the depreciation hit, but it throws off the usual time/miles calculations for preventive replacements that I'd used on previous cars. FCP Euro had injectors for ~$270 and Rock Auto had the seal kits for $30, so I decided to do those given the relatively low price and potential future labor saving. It seems a bit early (time and miles), but my rationale is that I only want to get in there once. I also have a tendency to learn the hard way, so we'll see.

I've also reused some single-use bolts with mixed success. Most recently I put Loctite on the dogbone bolt and torqued it to a reasonable value for the bolt diameter. It's been fine. If the single use bolts are cheap and I've planned adequately in advance, I've mostly been replacing them.

 

[Tamarancho]

@YamR1rider - Thank you for this thread! Your post + photos gave me the confidence to tackle the oil cooler bracket leak I found while doing my water pump on my 2015 Mk7 GTI. Overall, I thought that removing the oil cooler/aux bracket was less difficult than the intake manifold/water pump. Here's my experience:

To start, I did the water pump and thermostat replacement, mostly following the FCP Euro and HumbleMechanic youtube videos for water pump replacement and intake removal, respectively. Your note here about vacuum/pressure testing before reassembly is important! I got halfway through replacing the intake manifold before I decided to pressure test the coolant system. The coolant system was drained, so I pressure tested with air. I was losing about 3psi over 15 minutes, and I could hear a leak bubbling somewhere below the intake manifold. I pulled the manifold (goes faster the second time, at least) and found that my oil cooler bracket was leaking. I did the entire aux bracket/oil cooler job with the manifold removed. I agree that it does make it easier, but I wouldn't remove the manifold just for this job.

Oil cooler leak (this is with the intake manifold removed, underneath the cylinder 1 fuel injector).

Zoomed-out location of the leak:

I then franticly googled and searched the maintenance manual. Eventually, I found this thread. Related note, the oil cooler bracket goes by a lot of names: "Auxiliary Components Bracket" (service manual name), "Oil Cooler Bracket," "Alternator Bracket" (this brings up the most google results), "AC Compressor Bracket" and "Oil filter housing bracket."

I replaced both the oil cooler gasket (not leaking yet) and the auxiliary components bracket gasket, along with the bolts that mount them. Initially, I purchased the wrong gasket for the aux components bracket - engine code matters. I had to buy a specific CXCA gasket.

Here are the parts I bought:

• Oil cooler gasket: VW 06L117070
• Auxiliary components bracket gasket: Elring 279630 (This is good for CXCA engines only, I believe)
• Oil Cooler bolts (need 4x): VW N91048802 - these were M10 triple square, the bolts I removed were Torx T45, but they were same thread, thread pitch, and length.
• Aux Bracket bolts, upper (need 3x): VW N91045502
• Aux Bracket bolts, lower (need 2x): VW N91026802 - these were not quite right either, these bolts are M8 triple square whereas the originals are M10 triple square.

I used this thread as guide, along with three sections from the maintenance manual: "Auxiliary Components Bracket, Removing and Installing," "AC Compressor, Removing and Installing on Bracket" and "Generator, Removing and Installing, Vehicles with 2.0L TSI Engine."

I loosened the alternator bolts first, but I found that I had to unbolt the AC compressor to create enough space to fully remove the alternator. Unbolting the compressor lets you push the hoses towards the front of the car, creating a gap to lift the alternator out.

I hung the AC compressor from the hood latch mount plastic with paracord, I fed the paracord through the top bolt hole on the compressor. The compressor isn't that heavy but the manual says not to let the compressor hang on the refrigerant hoses. This was easy enough to rig up.

An unexpected challenge was removing the T30 that connects the dipstick tube to the aux bracket. You NEED a 1/4in drive T30 with a universal joint, or a T30 L-key, because the clearance is super tight.

My leak was only coolant, no oil yet. The gasket was super brittle, and broke into pieces when I removed it from the bracket. It was leaking at the red arrow:

After pressure testing the system - no leaks! - I put everything back together. No big hang-ups on reassembly. The top 3x bolts on the aux bracket (immediately around the seal) feel like they turn forever before they hit torque - I was sure I was going to pull the threads out. I think the gasket takes a lot of compression, and I hit torque + 90 degrees with no issue.

My GTI is now back together, and no longer leaking coolant!


Bonus before/after carbon cleaning. 90k miles on 2015 GTI. Mostly highway driven for the first 80k of it's life, but the last year has been <15 minute around-town trips.

 

[YamR1rider]

@Tamarancho - Good job, pleased it helped! Your writeup is also great, some good additional points there which will help the next person doing the job who stumbles across the thread.

Looks like you did a lot more thorough job on the valve cleaning than I did Did you walnut blast them?

 

[Tamarancho]

Thanks!

I did walnut blast them, alternating between walnut blasting and using picks to scrape. Walnut blasting was super effective at cleaning the mostly-scraped surfaces but wouldn't touch the large gooey pieces.

 

[YamR1rider]

Cool, yeah I think I will have to invest in a media blaster before I get round to doing the valves again....that whole spraying with carb cleaner and going at it cable ties (several go rounds) is tedious to say the least!