Carbon and DFI - Maintenance Tips?

[raykelly]

Well, never thought of it before until I was researching on my car. Came across quite a few people talking about carbon build up on the inlet valves on DFI engines and how it could cause problems down the line....

What does everyone here do as preventative maintenance?
I read a lot of things and have come to the conclusion that maybe Forte would be good to use very so often? Also saw that some people are bragging about Terraclean.

To be honest I think driving the car regular at optimum temp and changing oil frequently should be enough. However, if using some snake juice can help the longevity and performance of my motor, I will use it. Of course not causing any damage to other engine parts.

So.... what do you guys do here?

 

[guitarplayer63]

It's never occurred to me that this might be a problem, my 2008 Gen 2 has 82K on the clock and runs great, it gets a periodic trip to Germany to wind it up on the Autobahn (in my mind to offset some of the slow moving traffic we all get stuck in)....

I don't want to put snake juice in and then hear that excuse "ah well sir, you've put snake juice in and, well thats going to cost..."

 

[raykelly]

You see, I thought the same.... but after reading on what can be achieved using it and the carbon build up problems...has led me to ask here for peoples thoughts.....

 

[JCX]

I always use premium fuel and nearly always use shell vpower+. Rightly or wrongly I believe that it is cleaner than many fuels.

 

[tscaptain]

I had Terraclean run through my 28 year old 928 and it certainly lowered the emissions. Wouldn't dream of putting it through the turbo! Like Joe above just use Vpower all the time.

 

[raykelly]

I agree on the fuel for sure but no matter what fuel you use, they all produce carbon. I also would not like to mess with my engine but if this is something that can help maintenance wise....I guess the better fuel will definitely help the cylinder and injectors as they are exposed during the ignition of the better fuel... the inlet valve, Im pretty unsure how any of it such as the snake oil or fuel can have a cleaning affect on the inlet valves. For me the only way would be to feed something into the inlet manifold...and I'm not doing that!

As I said, I only came across some threads discussing this about DFI engines..

Maybe its just down to the common sense motto of.... Drive regularly, maintain regularly with recommended oil and parts, use correct fuel and enjoy!

 

[tscaptain]

Indeed so, Ray. And give it plenty of beans too. I think any gunking up of valves etc. is happening when they are not being driven hard enough.

 

[Ianstewartshouse1]

Mine should be spotless then

 

[dteagles]

No fuel additives are useful in the fight against carbon build up in DFI engines as the fuel never gets onto the back of the valves!

If Porsche got the design right and stopped the oil vapour from being "ingested" by the engine then there should be little worry about carbon build up.

Look at interwebs about folks getting R56 MINIs cleaned, this is due to a rubbish design on the breathing side of the engine, there's no oil separation (or at least it's not effective) and cars need to be cleaned at about 30-40k miles. We have a 2008 JCW and it needed a clean at about 38K miles when we bought it, I've added an oil separator on one side to help alleviate the issue but really need one the other side as well but this is more difficult!

 

[Les]

My 3.6 dfi is now on 103K. I use VPower and the occasional heavy right foot.

Runs like a dream.

 

[raykelly]

I was reading quite a few threads about the carbon build up.... the thing is... if fuel can not get to the back of valves.... you put the fuel additives into the fuel... so it still doesn't get to the back of the valves. Obviously I need to look into it more, as a lot are stating that it works. Maybe the additives don't completely burn up during the ignition cycle and become part of the oil etc... which helps to remove carbon from other engine parts..... I saw that people would run this through their system and then change their oil and filter afterwards... Might be an idea to run through the car before your oil service...

Les, 103K mile! promising! Mine only over 45K but I'm clocking over 9K/year now so wont be long catching up Car currently in getting the High pressure fuel pump changed.... you ever have that problem?