Heads up Carbon on Porky DI engines

[Andyuk911]

I have spoken about this before.,

This is just to provide a heads up on what WILL happen to the New Direct Injections Porsche engines,

ie 997 Gen 2 etc

http://www.planetporsche.net/cayman-boxster-chat/3...

My advise is regular oil changes and use of the Wynns products

http://www.wynns.be/news.aspx?l=EN&isectionid=...

[Andyuk911]

In a word yes.... it has great benefits for power and emissions ... but within a few thousand miles kills itself.

More cars will move to Direct Injection and over time the cleaners will get better

[Andyuk911]

AndrewKillington said:

Andyuk911 said:

In a word yes.... it has great benefits for power and emissions ... but within a few thousand miles kills itself.

Andy
What are the syptoms? loss of power? smoke?
Kills itself in a few thousand miles

Sorry, my post was a bit OTT ...

From known tests of Audi RS4s it takes about 2-4k miles for the carbon to build.

When I sold my RS4 at 30k miles, it was running absolutely fine .... but as somepoint if will need a decoke.

The point of the post was to show it happens to Porsche, hence the original link above.

The bottom line, over time performance will reduce ...

[Andyuk911]

Two Stallions said:

My Mitsubishi gradually started to run rough and stalled on a couple of occasions. De-coked and ran OK for about 20K miles!

Edited by Two Stallions on Monday 12th October 12:22

Did they clean it for free? ..... I bet not .... I think they should have done!

[Andyuk911]

Ian_UK1 said:

Andyuk911 said:

My advise is regular oil changes and use of the Wynns products

http://www.wynns.be/news.aspx?l=EN&isectionid=...

I'm not sure that the Wynns products will do any good - the deposits on the backs of the valves are so hard, they virtually have to be machined off. I've heard of workshops soaking the valves, once removed from the engine, for 24-hours or more in chemical cleaners (not unlike Wynns) to no avail. So unfortunately, I don't think a few milliseconds exposure to the spray as it passes the valves whilst the engine is operating will do anything at all.

Ian,

I do agree with you in one breath.

Wynns(and others) know the problem, they did produce a doc showing it helped.

The only real way is to a before and after ..... but I don't know anybody who could do this.

I wonder if Porsche will cough up to decoke an in warranty new 997 gen2.

I know of one RS4, that had a damaged to an injector and another with non sealing valve.

I think most manufactures will be forced to DI, purely to meet emissions ..

[Andyuk911]

D9000sp,

to clarify, even if you use super unleaded with all the cleaning additives, this does not stop the carbon as NO fuel passes the valves.

For a 996, this problem does not happen, as the fuel is injected into the intake track and 'washes' the valves. No coke will build up with Super unleaded.

There is a sound case to say a 997.1 will have better long term performance over a 997.2


ps

If you have a carbon issue, switch to Super unleaded(97/98/99)(it has cleaning additives), DON'T run 95 in your car.

Edited by Andyuk911 on Monday 12th October 20:14

pps

I have just noticed you are in the US ... get your customer to use high quality gas .... why don't you 'Seafoam' the car .. that will fix it ....then reset the ECU

Edited by Andyuk911 on Monday 12th October 20:50

[Andyuk911]

You are talking about a DIFFERENT issue to me.

To be clear, if you run a DI engine on the super duper fuel it WILL carbon up.

If you run a 996 etc 'normal' injection on super duper fuel it will NOT carbon up.

What you are speaking about is LOW GRADE GAS in the USA, this is NOT relevant to this thread.

[Andyuk911]

D900SP said:

Andyuk911 said:

You are talking about a DIFFERENT issue to me.

To be clear, if you run a DI engine on the super duper fuel it WILL carbon up.

If you run a 996 etc 'normal' injection on super duper fuel it will NOT carbon up.

What you are speaking about is LOW GRADE GAS in the USA, this is NOT relevant to this thread.

Don't forget the US and Europe use different RON/MON ratings for the same fuel. Although having said that the west coast CA/OR/WA are allegedly changing the fuel chemical structure.

Agreed I am aware of that.

What we have with UK Fuel is additives(cleaners) that are NOT added to the NON-Super Unleaded fuels.

So for your higher octane fuels, do any add cleaners, is what you need to ask.

You will then get the advantage of a more advanced ignition(more power) AND a clean engine.

[Andyuk911]

Off topic .... but shows what happens on a NON DI engine ...

[Andyuk911]

MTR,

I am afraid not.

DI is great for power and emissions, but thereafter 'pants'

A lot of other cars are going in this direction, including the Ferrari 458/ Lambo LP560/ etc..

Just google GDI carbon then you will get a picture of the problem.

It saddens me that Porsche have gone this route, especially how much info is known about the VW TFSI and Audi FSI engines.

Don't get me wrong the cars will run fine, but power will reduce as the carbon builds up on the back of the valves. Personally I don't want that to happen to my 'performance' car.

If it is just left and left, apart from the power reduction, you then end up with what you can read about the Mitsubishi GDI engine ..

If I buy another DI car, I will be doing regular oil changes(5k miles) and using DIP3 every 3k miles ...

[Andyuk911]

Koln-RS said:

mollytherocker said:

I am lost for words reading this! I really hope you guys are exaggerating the issue.

Why would Porsche have allowed such a major issue go to production? I am well aware of the 996 issues, but this is on another level altogether!!!!
MTR

I wouldn't jump to any conclusions just yet. If you take every scare story on the internet literally you'd never get out of bed in the morning - let alone buy a Porsche.

I am afraid it is fact, so I am posting a 'heads up', as I have said there are ways to reduce this.

[Andyuk911]

Agreed not the same as Audi, but the technical principal is.

The bottom line is that Direct injection into the cylinder head is a good idea. However the problem comes from the gas recirculation from the crankcase. Audi have 3 swirl pots to try and catch the oil out of the mist,unfortunate this has proved not to be successful and carbon builds.

I was hoping that Porsche had a magical way to stop this, but as the original post show this is not the case.

It is sad, but the gases from crankcase will have oil in them and this oil is what forms as carbon on the back of the valves as there is no fuel to dilute and clean.

More manufacturers will go this route as it is an easy way to reduce emissions and that can be a headline. Watch the Ferrari 458 launch ... reduced emissions was a key part of the speech for the new car.

The new Porsche DFI engine will not be immune from carbon ...

As they say, you pay your money and take your choice.

[Andyuk911]

DSM2 said:

Andyuk911 said:

MTR,

I am afraid not.

DI is great for power and emissions, but thereafter 'pants'

A lot of other cars are going in this direction, including the Ferrari 458/ Lambo LP560/ etc..

Just google GDI carbon then you will get a picture of the problem.

It saddens me that Porsche have gone this route, especially how much info is known about the VW TFSI and Audi FSI engines.

Don't get me wrong the cars will run fine, but power will reduce as the carbon builds up on the back of the valves. Personally I don't want that to happen to my 'performance' car.

If it is just left and left, apart from the power reduction, you then end up with what you can read about the Mitsubishi GDI engine ..

If I buy another DI car, I will be doing regular oil changes(5k miles) and using DIP3 every 3k miles ...

What's DIP3 and how do you use it?

It's the Wynn's product .. see link in first post.

[Andyuk911]

SFO said:

paddyhasneeds said:

Apologies for a bit of a swerve question, but is there any benefit with non-DI 9x7 Pork engines of putting through a tank of injector cleaner every so often or with modern engines that get frequent use with good quality fuel is there simply no need/benefit?

good question, I would like to know the answer too

There are products around, however I personally don't think they are necessary provided your run Super Unleaded that has more cleaners.

The pictures above show the difference between the 95 BP petrol and BP Ultimate.

Again you pay our money and take your choice.

[Andyuk911]

I suspect it is to do with emissions ..

This vid gives an idea how smart this all is ..

http://www.youtube.com/watch?v=PqZXyHp9cPk

[Andyuk911]

Hi bert,

have a watch, good explanation.

http://youtu.be/PS8riAae_bM

For Porsche, the Cayenne could be bad, however I suspect for 997 Gen II, the oil is of high quality and changed often and the mileage is typically lower. Also the gas recirculation system could be a better design, which would also help.

I would not be put off buying a 997 with a DI engine, after all the IMS issued was solved.

[Andyuk911]

Agreed, that does look an acceptable level, so no real concern.