# Carbon Build Up and Overall Reliability



## TurboDieselPoint (Jul 16, 2013)

Hi Folks,

It's going to be a sad day for my 2014 Passat TDI, because it's going to get sold back to Volkswagen and replaced with a 2017 Passat with the 1.8 TSI.

Has the 1.8 Gen 3 TSI shown to be as affected by intake valve carbon buildup as some of the earlier TSI engines? Is this something to worry about?

Also, have there been any glaring reliability issues with this engine that I should be aware of? Reading on this forum, I found a few murmurs here and there about rear main seals leaking, but I have no idea about the extent to which owners have been experiencing this failure and whether or not it has been corrected on the newest built cars by now.

Thank you and I very much look forward to joining you all in the near future!:wave:

TDP


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## Fitz Ingarage (Aug 25, 2008)

Here's a link to an extensive thread here that might help:

http://forums.vwvortex.com/showthread.php?7062280-Any-issues-or-flaws-with-the-1-8T-yet

I'm in the same boat as you, with us soon turning in our 2010 JSW TDI 6M and buying a 2017 Golf Wolfsburg 5M in replacement. In any case, I'm happy knowing that when our TDI makes its exit, the worry over a very expensive High Pressure Fuel Pump failure will also exit. :thumbup:

I'm wondering if the DIY sprays offered by CRC (Intake Valve Cleaner) and Gumout (Regane Direct Injection Intake Valve & Port Cleaner) might do some good. I read somewhere that Ford warns against using them on their Ecoboost engines, so I'm a little hesitant to use them on the Gen3 1.8T.


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## VR6OOM (Nov 8, 2002)

No, the carbon deposit issue isn't resolved because these motors still have a pcv system and we don't get the 2nd set of injectors, like in Europe, to wash the valves. The only solution is the dump those fumes completely. Since that's illegal, a catch can will slow it down, but anecdotally, deemed ineffective overall. I went with another solution. Since this is all oil-vapor being recirculated back into the intake, a good quality synthetic resistant to evaporation is key. There are lots of good oils that will resist evaporation more than others, but they're more expensive than over-the-counter mobil/castrol. I'm at almost 50k miles and I don't have to add a drop of oil between 10k oci's and I still get close to 38mpg highway, and I'm tuned too boot with heavy aftermarket 18's. I hope I won't need a carbon cleaning to well after 100k miles.

As for reliability, it seems VW went cheap on the the seals with this motor. My timing chain cover gasket failed at 30k. I have several friends in town with this motor and none have had any leaks. The problem is in the compounded forum world, you'll hear about the few issues and they may seem like issues, but overall they're not. The good news is: warranty.


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## PowerslavePA (Dec 9, 2014)

The carbon issue will NEVER be resolved. Gas does not flow over the
intake valves with Direct Injection, so it will always be an issue. To clean it,
you use the spray can of SeaFoam, with the special spray tube that will clamp
in your intake tube before the throttle body. Keep the RPMS at 2000 while 
it is sprayed into the intake, THUS going over the intake valves, and it will 
clean the carbon off the valves. Use the fuel additive for piston and exhaust
valve cleaning. 

You can never vent the crank case into the atmosphere legally, so there has to be a PCV
or CCV system. Install a catch can, and you will reduce that carbon and **** in the
intake ten fold. 

Direct Injection is totally different from Port Injection, the injectors are NOT
in the head, so as I said, the gas does not flow over the back side of the
intake valves, thus they never clean up. The SeaFoam will take care of
that, NOT the stuff you dump into the fuel tank, remember, NO fuel is
flowing over the valves, so you have to spray it in through the throttle body. 
This is true of all cars with Direct Injection. 

VW claims they alter the software in the ECU to cut back on carbon build up. 
Still won't prevent it... That's the side effect of DIRECT INJECTION.


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## VR6OOM (Nov 8, 2002)

Seafoam = snake oil


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## PowerslavePA (Dec 9, 2014)

VR6OOM said:


> Seafoam = snake oil


AS a gas additive, it's worthless.

Take your plugs out, and use a snake camera, and take pictures of
the tops of all your piston heads. Put the plugs back in, and run through
the spray can of SeaFoam, as specified.

When done, take the plugs back out, put that camera back down those,
holes again, and you'll see your misconception... 

Sorry, it's been proven to work. However, you can have your opinion.

I got 243,000 miles out of my TDI, never had any engine stumbles or
hesitations, compression issues, NOTHING. Never cleaned the intake 
valves manually. 

EVen if SeaFoam is snake oil, something will work, as long as it is run
through the intake, so it washes over the intake valves.


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## TurboDieselPoint (Jul 16, 2013)

Thanks for all of the responses.

I'm aware that carbon buildup is expected to occur to at least some degree on this engine since it is solely direct injection, after all. I asked my original question, however, because it seems to me that some manufacturers have found ways to slow or limit carbon buildup on their DI engines, even without a set of port injectors. Enhanced PCV systems, enhanced EGR, improved oil, and clever intake valve timing, among other tricks. I may be remembering incorrectly, but I seem to recall some of their DI engines can "burp" air and/or fuel mixture back into the intake runner temporarily at the end of intake stroke/beginning of compression stroke to help mitigate carbon buildup. As a result, most drivers never experience problems due to carbon with these engines, even in the long run.

I was wondering if VW has reached this level yet. Are most 1.8 TSI owners having to get routine valve cleanings, just as owners of the older TSI engines do, or is this something I shouldn't realistically have to have performed?


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## TurboDieselPoint (Jul 16, 2013)

Forgot to ask...

Do the non-dsg 6-speed automatic transmission-equipped 1.8 2017 Passats have Dual Mass Flywheels (DMF)? I remember these were a failure point on some TDIs.

Thanks


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## PowerslavePA (Dec 9, 2014)

TurboDieselPoint said:


> Forgot to ask...
> 
> Do the non-dsg 6-speed automatic transmission-equipped 1.8 2017 Passats have Dual Mass Flywheels (DMF)? I remember these were a failure point on some TDIs.
> 
> Thanks


All the DSGs have DMFs. You can only change to the single mass in a standard.
They are a failure point. You'll hear it knocking out of gear when it starts to go bad.

AS for the prior reply, VW does have programming changes to help prevent
carbon build up. Not sure they burp gas back through. The intake valves 
actually close before the upward movement of the compression stroke. If
they didn't, you'd get air back through the intake, you'd hear that. So, not sure 
when they'd be able to spray it in, and have it pushed back through the intake 
valves... VW just explains how they use programming and timing to help with
carbon build up.


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## TurboDieselPoint (Jul 16, 2013)

Thanks for letting me know about VW's response to carbon build up. I guess we will just have to take VW's word for it, huh?

Yes, I know that all DSGs come with DMFs (so does my manual TDI). However, I am pretty sure that my upcoming new 2017 Passat 1.8 with the traditional torque converter 6-speed automatic (NOT a DSG) will not come with a DMF. Is this correct?


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## PowerslavePA (Dec 9, 2014)

The DMF is made to absorb vibrations from the engine. It's a spring loaded
fly-wheel, good and sound idea and application, but the thing literally falls apart.
I saw one where a spring actually broke through the flywheel, and scored the
bell housing. 

With a standard, you can replace the DMF with a SMF, and never have to
worry about it, but the engine vibrations will be more prominent. 

Regular automatics with the torque converter don't need the DMF for
the reason they use it, since the torque converter basically does that
naturally. It being filled with fluid dampens the engine vibrations.


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## VR6OOM (Nov 8, 2002)

PowerslavePA said:


> AS a gas additive, it's worthless.
> 
> Take your plugs out, and use a snake camera, and take pictures of
> the tops of all your piston heads. Put the plugs back in, and run through
> ...


FSI/TSI guys have proven it doesn't remove intake valve deposits, which is what the OP was asking. If it was proven to work, then intake valve deposits wouldn't be a hot-button topic. There is a B&G service (more intensive than Seafoam) and it works slightly. It will remove the softer outer layer. Hell, even water/meth injection won't remove intake valve deposits.


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## evantful (May 14, 2011)

I have to agree with VR6OOM on this. I had a 2009 MK5 GTi with the 2.0TSI and religiously did Seafoam cleaning through the intake every 5k miles. Inspected the Valves at 80k and they had significant carbon build up. The SeaFoam is simply not coming into contact with the carbon (mind you large amounts of carbon over a 5k period) that it can break it down in any manner for such a short duration of application. I suspect if I could completely remove the valves, submerge them in a container of seafoam for hours over night then it would have a result.

At the same time I have used Seafoam as a cleaning solvent on other projects and I can attest that it does work in certain applications, but basically not in any manner they generally advertise. 

That being said PowersalvePA its nice to see you over here outside of TDIClub


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