HumbleMechanic- carbon buildup on 10k mile 2019 Golf R

Joined
Jun 27, 2017
Messages
2,014
Location
OK
I stumbled across the HumbleMechanic's video investigating carbon buildup on his fairly new Golf R over the weekend and thought it was pretty interesting. I've been thinking about a VW for my next car, but I would have to come up with a good plan to deal with the carbon buildup issue first. Unfortunately, it looks like he tried everything that I would've done and it didn't seem to help. Are VW owners just going to have to plan for a regular interval for carbon cleaning?
 
Adding oil and fuel treatments invalidates this video in my mind. How does one know the additives are not to blame for the buildup?
 
I owned a 2013 GTI with the mentioned TSI CCTA engine he spoke of in the video. Bougfht the car new. The intake manifold failed at 82K miles. Two stage intake and the secondaries wouldn't open up. I cleaned the intake valves, intake ports, injectors while doing that repair and they looked horrific. The car didin't run any faster or slower before or after the cleaning process. I did get a little better fuel mileage however. I think the turbo boost and ECU mask the issue.
I think there is a pro and con to intake deposits vs power, feel of the engine, something. Sucks.
VW and Audi gas direct injection turbo engines feel better to drive than other makers, but at the cost of intake valve deposits. I don't think you can have the best of all worlds.
 
Originally Posted by Vercingetorix
Adding oil and fuel treatments invalidates this video in my mind. How does one know the additives are not to blame for the buildup?


Good point, but I don't think the hexagonal boron burns or chars...

I watched him explaining diesel fuel systems a few years ago and realised within seconds that wasn't his forte....
 
Glad I Leased my VW. It is Going back to VW with about 16,000 Miles over 2 years.
Mine seems to idle fine.

Performance is very Fuel quality and oil viscosity dependent.

Shell V-power sold near me is garbage. Never performed well. Actually perfomed terrible.

I've settled on running a blend of Irving and Mobil 87 octane fuels they (usually) keep it running like a banshee.

On OIl, If my 1.4 wants more than the 0W20 HTHS so does this Golf R with even higher specific output.

a 1/2 Litre of M1 0W40 FS fixed mine. Before boosting the viscosity, it would not make power and it was way too noisy.


So why is the HumbleMechanic running Ceretec and other LM snake oils?

And How is the crankcase blow-by handled on these cars? Can you keep it OUT of the intake?

With Positive pressure on the Manifold and a late intake event, you should not have as much reversion.
And a bit viscosity should help at least tiny bit with valve stem oil leakage

I think he needs a Lubricant and Fuel lesson.

Ken - a NOT so humble mechanic
smile.gif
 
Last edited:
IMO, GDI (and GDI Turbo in particular) are not fully developed technologies....and the consumer is paying the price.
They are a response to government mandated fuel economy requirements (from a gov't that can't even balance it's checkbook).

I would avoid several brands (like VW) until the technology is mature....
 
What would drive me nuts as a VW/Audi owner would be knowing that VW AG would not sell engines equipped with the dual-injection set up for the US market. VW are already on the more expensive side of the econobox market I guess an extra $1k for the dual injection setup available in ROW is just too much.
 
Last edited:
So, to go ahead and get out in front and clarify things- I'm not defending his video or saying that it's without fail. I just thought it would make for some good discussion, especially around a subject that has been front and center since DI has become more prevalent. Also, this isn't a bash on VW thread. I actually really like VW and would love to purchase one at some point, but like I said originally, I'd have to figure out something with the carbon deposits. Or maybe it's like skyactiv said, it's just the trade off you have to make and therefore you have to plan on getting carbon removal done at a fixed interval. It could be worth it to some for how well the cars can perform.


However, to play devil's advocate- I would argue that adding anything to the oil or fuel does not invalidate his results. You have to take into account the history of these motors. You can't really ask how we know if these additives didn't cause the buildup when you're dealing with an engine that is widely known for creating carbon buildup anyways. He even explains how he knows it's going to be an issue, so he tries some other methods to prevent it. If you spent years as a VW technician and saw this problem, then went out and bought a car with the same problematic engine, you'd probably try to do something to prevent it, too.
 
Originally Posted by JustN89
So, to go ahead and get out in front and clarify things- I'm not defending his video or saying that it's without fail. I just thought it would make for some good discussion, especially around a subject that has been front and center since DI has become more prevalent. Also, this isn't a bash on VW thread. I actually really like VW and would love to purchase one at some point, but like I said originally, I'd have to figure out something with the carbon deposits. Or maybe it's like skyactiv said, it's just the trade off you have to make and therefore you have to plan on getting carbon removal done at a fixed interval. It could be worth it to some for how well the cars can perform.


However, to play devil's advocate- I would argue that adding anything to the oil or fuel does not invalidate his results. You have to take into account the history of these motors. You can't really ask how we know if these additives didn't cause the buildup when you're dealing with an engine that is widely known for creating carbon buildup anyways. He even explains how he knows it's going to be an issue, so he tries some other methods to prevent it. If you spent years as a VW technician and saw this problem, then went out and bought a car with the same problematic engine, you'd probably try to do something to prevent it, too.



IIRC Humble Mechanic installed a catch can on this vehicle after the fact. He has also said that this engine family was known to have running issues when buildup got to a certain point. He was a master VW tech afterall.
 
My mom was one of the first 50 to buy an Audi A3 in the US and we still have the car with 175k miles on it. Early FSI were notorious for CBU, oil burning, and fuel dilution. Yes it did have carbon build up but it wasn't till 161k miles It started to have a cold start misfire. $395 later all fixed by having a shop walnut blast the build up; I'll have to post pics sometime. The car burns through a quart of oil about every 8k miles. Early PCV caused the car to burn 1qt fairly quickly but all is well. I did change the computer to flexible oil service with max 12k miles and min 3k miles, no more than 1 year and it seems to settle on 8k mils oil changes which is when it burns through a quart which is convenient. Honestly, either we have a unicorn or the problem is overblown. A $500 service every 150k+ miles is $0.003/mile which is nothing.
 
Carbon Cleaning is something you have to expect with a DI vehicle. You don't just get all that extra power and economy for free.
 
Humble Mech. did stage 2 tune very early on and I wonder if that contributed to it at such a low millage.
 
Originally Posted by skyactiv
VW and Audi gas direct injection turbo engines feel better to drive than other makers, but at the cost of intake valve deposits. I don't think you can have the best of all worlds.

You can. It's called "port AND direct injection"
 
At 10k miles?! Wow.

So much for:
Italian tune-up
Euro oils ( he's done two 5k mi intervals with VW508)
Low Noack
Synthetic oils in general
Top Tier
and
Catch cans

None of this appears to be working.
 
Originally Posted by Lolvoguy
Originally Posted by skyactiv
VW and Audi gas direct injection turbo engines feel better to drive than other makers, but at the cost of intake valve deposits. I don't think you can have the best of all worlds.

You can. It's called "port AND direct injection"


Exactly. And one having something to do with other is a red herring. There are tons of fun to drive cars that we don't hear of having this issue. I love my Passat but this is disappointing.
 
Originally Posted by rob1715
Gonna have another catch can debate?

We haven't had many since February, were you here before that?
 
Back
Top