Edition 30 - Large Carbon deposits on Injectors

[RedRobin]

If I tried to redline the car I would shift up well before 6K usually due to the engine noise which was loud. It seems to hit higher rpms a bit better but I'm still not convinced it sounds great at 6K + rpms

....On the 2.0T FSI engine it's much better to shift gear at about 5,500 max - There's less power at higher revs and it's not great for the engine longer term.

[Richn83]

Although he does have a K04 so he might have a stronger power higher up.... _{Although im with you robin and avoid over revving unless required, love a bit of low down grunt, if I wanted to rev the nuts off a car I would have an RX8}

[AnSGTI]

Cheers fort the replies guys -  I'm not this mad guy that drives cars to the limit, it was just when I started making enquirees about my issues a lot of poepl asked how the car accelrated to red line. I could do this in my 1.8T quite easily but in the ED30 I bail out - just wondered if all of my issues were related thats all. Anyway think I'm just going to take the advice of the kind people on here and enjoy the car and wear ear defenders when I'm starting up from now on 

[john_o]

just buy a boost gauge , that will take your eye off the rev counter needle 

[Teutonic_Tamer]

personally I would not recommend holding the starter any longer than reqd, it achieves nothing (other than risking damaging  things!)

Huh - what in a starter motor can be damaged by simply using it ?????  It is perfectly OK to crank with the starter for upto 20 second continuous bursts.  The issue then is that you need to 'rest it' for 30 seconds between each operation.

[Teutonic_Tamer]

The report, which I hope to get a copy of, suggested a 10% increase in dispersal once they had cleaned an injector. Under a cold start I'm guessing the injector will be using a slightly different spray patterrn so maybe this accounts for my problem, I hope.

Injector spray pattern is fixed.  The only variables are duration, and number of actual injector cycles per engine stroke.

The report did also suggest that these large carbon deposits could point to a combustion issue so I'm guessing this could be timming/spark issue - a compression check was fine so that all I can think of really.

Could it be the place who tested them is not familiar with FSI direct injection.  Old skool manifold injection will basically have zero carbon on the injectors.  But on our FSI engines, because the injectors are sited in the actual combustion chamber, then they will have the same amount of carbon as spark plugs.  Carbon deposits on FSI injectors, and spark plugs is not really unusual.

What they need to do is check the spark plugs too - and compare injector tips with spark plugs.  And more importantly - confirm what type of carbon it is - ie, is it from petrol or oil?  Simple basic fundamental diagnosies which any basic vehicle mech/tech should be able to do.

And rather than fannying around with old skool injector testing - they should just authorise a new set and be done with.

[Teutonic_Tamer]

Yeah I know these things happen, just never had it happen to me before  

I am feeling generally happier about it now - especially as I just had a curtsey call from the workshop manager and he said he'd given them the 'all go' to get them cleaned and he expects them back Friday, maybe Saturday. Something interesting he told me was that the injectors were tested at 400RPM pre/post clean and at this level they saw a 14% increase, the 10% increase was at a higher RPM. It's around 400RPM that my golf splutters on start-up, anyway as JOHN_O has rightly stated I shouldn't get ahead of myself and we need to see what happens when the injectors are re-fitted.

I have also asked the garage to check the intake valves while the intake is off - if carbon levels are high here, rather than getting them to clean them would I be right in thinking a good thrash with V-Power (over 3K RPM) for a long drive may help loosen these deposits? Or is a manual clean the only way?

As your injectors spray directly into the cylinder under the compression stroke and the v-power doesn't get anywhere near your intake valves a manual clean or water/meth injection is the only options for cleaning of the intake valves 

Not always.  During cold start mode, the injectors are fired 3 times per cycle - during the induction stroke, then near top of compression stroke, and then with a long squirt during the exhaust stroke.

Secondly, the aromatic additives in V-Power/Tesco 99/BP Ultimate etc, along with the high levels of concentrated detergents in the fuel cleaning additives such as Wurth/Forte etc - will all eventually find their way onto the back side of the inlet valves - simply down to oil dilution from FSI-specific over-fueling.

[Teutonic_Tamer]

One positive though, pointed out to me by a mechanic; at least when the engine oil has not reached around the engine, it's only doing 4-500 rpm and not 1200+ rpm!

Then he isn't a very competent mechanic - and certainly doesn't understand how either actual lubricants, and/or lubrication systems work.

Why do engines 'fast idle' when started from cold?

What do synthetic polarised oil molecules do?

What does boundary lubrication vs hydrodynamic lubrication mean?


I bet he can't even stab at an answer to those three points!

[Teutonic_Tamer]

Well it's getting worse what ever it is - I don't want this car anymore so I'm going to speak to trading standards

http://www.flickr.com/photos/16099319@N03/5061478161/

Look how it shakes on start-up - it's an embarrassment

Whilst I agree it shouldn't shake like that - I really think you are coming off the starter way too quickly.  You should NOT release the key until the engine has fired and is running under its own steam.

And don't worry about damaging your starter - because they will automatically kill the voltage to the starter when teh engine reached a certain revs (figure taken from the crankshaft position sensor).

[Teutonic_Tamer]

Just a few things to look at if they have not been looked at already:

Correct fuel pressure when cranking

Agreed.

Fuel pump follower

Don't really agree.  Problems regarding the fuel pump follower are only likely to be evident during high revs, high engine loadings.  Starting and idling will put a negligable duty on the HPFP.

Cam timing
Cam chain tensioner is ok

Hmmmm . . . if they are out, then VCDS will log a fault, and the MIL will light up, pushing the engine to limp home mode - so no, don't agree.

Spark Plugs

And . . . again, just like the high pressure fuel side - faulty spark plugs will generally show up under hard engine loads.

Air leaks, do a pressure test

From where?  You are now just clutching at straws!

Diverter Valve

Yeah . . . . rite . . . . so just how much boost, on an Edition 30 is being generated at tick-over?

Cat is still in one piece

Does it rattle?  And what about closed-loop lambda control?

Again, clutching at straws without actually thinking . . .

Turbo spins freely

Have you been geting your technical advice from Ceebeebies?

You mentioned carbon build up on the intake valves, did they find anything?

All FSI engines will have carbon build up on the intake valves.

And all non-FSI engines will also have carbon on said valves. . . . .

[Teutonic_Tamer]

ok forum people , any other suggestions that are closer to home for AnsGTI ?

Auto APS at Brackley

R-Tech at Hinckley, Leicestershire

VW Racing at Milton Keynes

Awesome GTI at Manchester.


Or bring it along to the Santa Pod meet next sunday for the rest of us forumites to ponder over.

[vRSAlex]

Just a few things to look at if they have not been looked at already:

Correct fuel pressure when cranking

Agreed.

 

Fuel pump follower

Don't really agree.  Problems regarding the fuel pump follower are only likely to be evident during high revs, high engine loadings.  Starting and idling will put a negligable duty on the HPFP.

I have had a broken follower cause starting issues as the cam wasnt pushing the fuel pump enough to get correct starting pressure
.

Spark Plugs

And . . . again, just like the high pressure fuel side - faulty spark plugs will generally show up under hard engine loads.

You can still get miss sparks when cranking, but yes it should show up under driving too.

Air leaks, do a pressure test

From where?  You are now just clutching at straws!

You can pressure test before the turbo and after the turbo.  If there are any leaks then they can cause starting ussues.

Diverter Valve

Yeah . . . . rite . . . . so just how much boost, on an Edition 30 is being generated at tick-over?

Its not about producing boost.  If there is extra air getting in then it takes more for the engine to start.

Cat is still in one piece

Does it rattle?  And what about closed-loop lambda control?

Again, clutching at straws without actually thinking . . .

If the cat is blocked then it stops air getting out of the exhaust.  May not show a starting issue, but the car also isnt driving that well.  I guess you have put your foot on the end of an exhaust before and it can cause the engine to stall.

Turbo spins freely

Have you been geting your technical advice from Ceebeebies?

 

You mentioned carbon build up on the intake valves, did they find anything?

All FSI engines will have carbon build up on the intake valves.

And all non-FSI engines will also have carbon on said valves. . . . .

Yes they will all have carbon build up on the valves, but some have excess amounts of carbon build up on the valve.  This restricts air flow to the engine.

I want to give as many suggestions as possible to help the guy out.  A starting issue could be one of many different things and if i can help then I will.  Im cool with constructive critisism with realistic resoning.

Dont forget that we are in MK and can try and help you with you problem.

BDMAlex

[Teutonic_Tamer]

OK, lets go back to basics, and more importantly, look at the thread title - Large Carbon deposits on Injectors - and then try to tailor advice to fit the symptoms - rather than throwing absolutely every conceiveable cause of non-starting into the melting pot.  I trust you've heard the phrase 'less is more'. 

Fuel pump follower

Don't really agree.  Problems regarding the fuel pump follower are only likely to be evident during high revs, high engine loadings.  Starting and idling will put a negligable duty on the HPFP.

I have had a broken follower cause starting issues as the cam wasnt pushing the fuel pump enough to get correct starting pressure.

OK, fairy-nuff, but a broken follower is likey to make a noise.  However, in this specific instance, the OP has not reported any 'noise' which is likely to be a broken cam.  Also, if there was an issue with a broken fuel pump follower - the ECU would log DTCs relating to low fuel pressure, and is highly likely to go into limp home mode - I don't recall the OP indicating any such actions. 

Spark Plugs

And . . . again, just like the high pressure fuel side - faulty spark plugs will generally show up under hard engine loads.

You can still get miss sparks when cranking, but yes it should show up under driving too.

Agree - fully.  What I am trying to state is that faulty spark plugs do not exclusively affect starting issues - the OP (IIRC) said it goes like stink when running normally - so it is increadibly unlikey that dodgy spark plugs are the cause of the OPs problems.

Air leaks, do a pressure test

From where?  You are now just clutching at straws!

You can pressure test before the turbo and after the turbo.  If there are any leaks then they can cause starting ussues.

Huh - a pressure test BEFORE the turbo will reveal exacty what????  Exactly the same as your baramoeter in your porch!  ALL Bosch MED ECUs include atmospheric compensation - so this test is as good as useless.

But again, whilst I agree that air leaks will potentially cause starting issues, they will also be more than apparent under load - and the OP reported no such issues.

Diverter Valve

Yeah . . . . rite . . . . so just how much boost, on an Edition 30 is being generated at tick-over?

Its not about producing boost.  If there is extra air getting in then it takes more for the engine to start.

Huh - from that explanation, you seem to not know how the diverter valve works.  It does NOT vent to atmosphere, it is a closed loop recirculating valve - so a faulty DV (unless it has been physically smashed off with a big rock) will NOT have any effect on starting, nor on tickover, nor upto about 2,250 (on a K04 car).

Cat is still in one piece

Does it rattle?  And what about closed-loop lambda control?

Again, clutching at straws without actually thinking . . .

If the cat is blocked then it stops air getting out of the exhaust.  May not show a starting issue, but the car also isnt driving that well.  I guess you have put your foot on the end of an exhaust before and it can cause the engine to stall.

I agree if the cat was blocked, it would prevent exhaust gasses exiting.  But the dash would be lit up like a christmas tree LONG before any sniff of a cat blockage.  And I certainly don't recall the OP stating his car wasn't driving well.

Secondly, do you know how cats get blocked?  Even if an engine is burning masses of oil (ie, serious smoke screens in your rear window), the cat blocks quite slowly, and progressively.  It is highly unlikely that a cat would ever get totally blocked from burning oil.

The usual way for a cat to block is if they have sustained a very hard impact - either by driving over quite a large rock - or a dodgy mechanic hitting them hard with a club hammer.  Both instances will clearly show impact damage on the outer metal casing of the cat!

Turbo spins freely

Have you been geting your technical advice from Ceebeebies?

 

Sorry - perhaps I should have added a naughty smiley!

 

You mentioned carbon build up on the intake valves, did they find anything?

All FSI engines will have carbon build up on the intake valves.

And all non-FSI engines will also have carbon on said valves. . . . .

Yes they will all have carbon build up on the valves, but some have excess amounts of carbon build up on the valve.  This restricts air flow to the engine.

Sorry - but this has got to be THE greatest load of internet bull$hit about FSI engines.

IF there was any substancial build up of carbon, this would still NOT affect low speed or starting issues.

I want to give as many suggestions as possible to help the guy out.  A starting issue could be one of many different things and if i can help then I will.  Im cool with constructive critisism with realistic resoning.

Fairy-nuff.  But there are plenty of stories of incompetent main dealers who can NOT correctly diagnose problems, and charge customers for completely needless diagnostic proceedures - and many of your suggestions do NOT fit the symptoms the OP described.  Surely, we should all be trying to save other fourmites money, not encouraging them to spend more!

 

[RedRobin]

Surely, we should all be trying to save other fourmites money, not encouraging them to spend more!

....Sorry to go off-topic for a second but I need to remind you of what's written:



Back on topic: A most interesting and educational discussion and am glad it's calm and not heated! 

[Teutonic_Tamer]

She can nursey me any day!