Edition 30 - Large Carbon deposits on Injectors

[Mako V12V]

I wasn't dissin you at all, merely pointing out that if I go back to the garage some 5 months after having the oil change done stating that one person has told me the wrong oil has been put in, then they're gonna laugh at me.
However, you have pointed me in the right direction to go armed with facts so I'll see where I get with them now.
Thanx

[AnSGTI]

I spoke to my specialist on Friday morning and mentioned my car had 10W40 in it and he was quite stumped as well. His first response was that a s you have pointed out they are meant to be run on synthetic oil. I asked what he would put in it, keeping it on time and distance and he would put 0W30  in it. I think I'm going to get an oil change this week and keep it 0W30 (providing other people agree this is the correct oil?).

Could this oil be a contributing factor to the cold start woes? Should I run anything else through the engine when changing the oil to get all the 10W40 out?

PS Every forum I have searched says synthetic based oil (0W30 / 5W30) and I'm far more likely to believe the good people on the internet. 

[vRStu]

Anyway, starting.  I have another theory.  The FSI system uses two fuel circuits - a conventional low pressure circuit (just like old skool fuel injection) - which delivers a high volume but relatively low pressure (6.4 bar).  And then there is the high pressure side - is a low volume (relatively) but high pressure (130 bar).  The high pressure side should keep a residual pressure in the common rail which supplies the four injectors (you have to manually release the pressure when working on the high pressure side) - and I reckon that some motors may not be holding enough residual pressure overnight.  And then the engine needs to be physically turning before the high pressure can be fully built up again.  Have you read the 'cold start' thread in this section?

Not forgetting of course that the process of opening the drivers door will/should charge the fuel system.

Perhaps try unlocking the car, open the door then close and lock the door and repeat the process again before starting - see if this helps with the problem and may then point you in a better direction.

[Teutonic_Tamer]

I wasn't dissin you at all, merely pointing out that if I go back to the garage some 5 months after having the oil change done stating that one person has told me the wrong oil has been put in, then they're gonna laugh at me.
However, you have pointed me in the right direction to go armed with facts so I'll see where I get with them now.
Thanx

OK - no offence taken.

And another avenue to 'prove' to the stealer - there is an organisation called www.OATS.co.uk.  They run the 'EARL' lubricants database, which is used by all the oil companies, and gets its info from all the car manufacturers, and generates a model-specific whole car lubricant spec guide.  If you log onto any of the major oil companies web sites (say www.Castrol.com/uk), and then select something like 'find lubes for my car' - Castrol will then generate an OATS profile for your car with Castrol specific lubes.  And importantly, when you select say Golf Mk5 GTI - ityou the option of PR: QG1 or QG0 (which are T&D servicing or LL servicing) - and for both, it will only list Castrol EDGE 5w30.  All other oil companies, including Fuchs, Millers oils, even shyte Motaquip - all state 5w30.

HTH, and good luck. 

[RedRobin]

@ Sean:

Is Fuchs 5w30 okay?

[Teutonic_Tamer]

I spoke to my specialist on Friday morning and mentioned my car had 10W40 in it and he was quite stumped as well. His first response was that a s you have pointed out they are meant to be run on synthetic oil. I asked what he would put in it, keeping it on time and distance and he would put 0W30  in it. I think I'm going to get an oil change this week and keep it 0W30 (providing other people agree this is the correct oil?).

0w30 was the slightly earlier LongLife 2 spec oil.  These arn't really suitable for FSI direct injection engines.  Also, the 0w30 oils tended to have a bit of 'drink problem' - because they were such a low viscosity, on certain cars they suffered with really high oil consumption.

Could this oil be a contributing factor to the cold start woes?

It's hard to categorically state that the wrong oil has caused your specific cold start issues.  However, theoretically, it could affect it.  A 10w40 oil is harder to 'pump' when cold, and therefore may marginally slow the cranking speed.  And the fact that virtually all 10w40 oils are not 'clean' oils (oils made with cleaner, safer additives - in a similar vein to removing lead from petrol) - using a 10w40 might be like running 4 star leaded petrol.  All those nasty additives when burned in the engine may be contaminating things like the catalysts and the lambda sensors.

Should I run anything else through the engine when changing the oil to get all the 10W40 out?

No - categorically not.  Just drain the sump and change the filter after giving it a good run - and then fill it with some proper stuff.

PS Every forum I have searched says synthetic based oil (0W30 / 5W30) and I'm far more likely to believe the good people on the internet. 

You really need to get your head around the official VW oil standards, rather than chasing oil viscosities or synthetics or not.  If you look for the correct VW oil standard of 504.00 - then the viscosity and basestocks will be all taken care of (ALL 504.00 oils are 5w30).

HTH

[Teutonic_Tamer]

Anyway, starting.  I have another theory.  The FSI system uses two fuel circuits - a conventional low pressure circuit (just like old skool fuel injection) - which delivers a high volume but relatively low pressure (6.4 bar).  And then there is the high pressure side - is a low volume (relatively) but high pressure (130 bar).  The high pressure side should keep a residual pressure in the common rail which supplies the four injectors (you have to manually release the pressure when working on the high pressure side) - and I reckon that some motors may not be holding enough residual pressure overnight.  And then the engine needs to be physically turning before the high pressure can be fully built up again.  Have you read the 'cold start' thread in this section?

Not forgetting of course that the process of opening the drivers door will/should charge the fuel system.

Perhaps try unlocking the car, open the door then close and lock the door and repeat the process again before starting - see if this helps with the problem and may then point you in a better direction.

That is a very good point.  Basically 'double priming' the low pressure side.

Though I personally still reckon these cold start issues are more likely down to the high pressure side not holding an adequate reserve pressure overnight.

[Teutonic_Tamer]

@ Sean:

Is Fuchs 5w30 okay?

Which Fuchs 5w30?  Fuchs make 11 different 5w30 oils - and only two of them are VW 504.00 approved!

The two Fuchs ones are:

• Fuchs Titan GT1 LongLife III - this oil is more suited to TFSI petrols
• Fuchs Titan GT1 Pro C3 - the phosporous content in this oil is more suited to diesels with DPF

And whilst Fuchs are a very good German oil - I would still put Castrol and Motul at the top of the pecking order, above Fuchs.

[Mako V12V]

I checked today and the top up oil I was given, being the same 10W 40 put in at service is classed as 505.00 oil. I shall be having words tomorrow.

[Teutonic_Tamer]

I checked today and the top up oil I was given, being the same 10W 40 put in at service is classed as 505.00 oil. I shall be having words tomorrow.

I think I mentioned earlier, 505.00 is only for DIESELS - and very old low spec ones at that.  There really is no way they can waffle their way out of this issue.

Good luck, and keep us updated.

[AnSGTI]

OK - I'll get some Castrol 5W30 and get the filter changed with a new sump plug and washer. Thanks Sean, you are an extremely knowledgeable guy! 

Can I run one more thing past you please? I mentioned below when I had my first morning of clearing frost from the car I was half expecting a really difficult start given the issue I've had. When I turned the key the starter appeared to turn for slightly longer than usual before the engine caught, but when it did catch it fired up very smoothly. This morning was another cold one (-0.5) so after scraping the frost from the car I turned the ignition on, waited then turned it over and it started very quickly and very smoothly - like I've said before it was as though the car had already been running but it hadn't been. So the really cold weather makes my car start smoothly 

Mako V12V - let me know how you get on with VW and the 10W40 saga, I may consider raising this with VW UK as well if this is the route you decide to go down. Also how is your ED30 starting in the cold weather?

[Teutonic_Tamer]

OK - I'll get some Castrol 5W30 and get the filter changed with a new sump plug and washer.

• 06D 115 562 - oil filter element kit - £9.50 +vat retail, £5.23 +vat trade
• N 908 132 02 - drain plug with integrated washer - £1.14 +vat

Thanks Sean, you are an extremely knowledgeable guy! 

Can I run one more thing past you please? I mentioned below when I had my first morning of clearing frost from the car I was half expecting a really difficult start given the issue I've had. When I turned the key the starter appeared to turn for slightly longer than usual before the engine caught, but when it did catch it fired up very smoothly. This morning was another cold one (-0.5) so after scraping the frost from the car I turned the ignition on, waited then turned it over and it started very quickly and very smoothly - like I've said before it was as though the car had already been running but it hadn't been. So the really cold weather makes my car start smoothly 

OK, so if the colder it is, the better it starts - then this is primarily a fueling issue.  Basically, the engine is being overfueled during starting.  The colder the engine, the more it needs 'more fuel' to start.  But if it is less cold, and too much fuel is delivered, then there is potential that the spark plugs will suffer from 'cold fouling' (excess wet carbon - not able to be burned off quickly enough, and the wetness then causes short circuit in the spark plug).  I think someone previously mentioned the Engine Coolant Temperature sensor (G62).  These do seem to be occasionally problematic, and unfortunately, when faulty, they wont log an error in the ECU.  For the sake of £20ish, it would be well worth a punt on fitting a new one.  This should then ensure better more accurate low temperature fueling.

And have I mentioned spark plugs?  Are the correct ones fitted, and are they in good condition?


Another thing to check is your tumble flaps.  These affect the airflow into the combustion chamber, and aid low speed combustion.  These are fairly common for seizing up.  Though if faulty, these are more likely to affect low engine speed running too.

[RedRobin]

Another thing to check is your tumble flaps.

....[said in a Terry Thomas voice:] "Well, helloo. How are your tumble flaps, my dear?"   

[AnSGTI]

OK - I'll get some Castrol 5W30 and get the filter changed with a new sump plug and washer.

• 06D 115 562 - oil filter element kit - £9.50 +vat retail, £5.23 +vat trade
• N 908 132 02 - drain plug with integrated washer - £1.14 +vat

Thanks Sean, you are an extremely knowledgeable guy! 

Can I run one more thing past you please? I mentioned below when I had my first morning of clearing frost from the car I was half expecting a really difficult start given the issue I've had. When I turned the key the starter appeared to turn for slightly longer than usual before the engine caught, but when it did catch it fired up very smoothly. This morning was another cold one (-0.5) so after scraping the frost from the car I turned the ignition on, waited then turned it over and it started very quickly and very smoothly - like I've said before it was as though the car had already been running but it hadn't been. So the really cold weather makes my car start smoothly 

OK, so if the colder it is, the better it starts - then this is primarily a fueling issue.  Basically, the engine is being overfueled during starting.  The colder the engine, the more it needs 'more fuel' to start.  But if it is less cold, and too much fuel is delivered, then there is potential that the spark plugs will suffer from 'cold fouling' (excess wet carbon - not able to be burned off quickly enough, and the wetness then causes short circuit in the spark plug).  I think someone previously mentioned the Engine Coolant Temperature sensor (G62).  These do seem to be occasionally problematic, and unfortunately, when faulty, they wont log an error in the ECU.  For the sake of £20ish, it would be well worth a punt on fitting a new one.  This should then ensure better more accurate low temperature fueling.

And have I mentioned spark plugs?  Are the correct ones fitted, and are they in good condition?


Another thing to check is your tumble flaps.  These affect the airflow into the combustion chamber, and aid low speed combustion.  These are fairly common for seizing up.  Though if faulty, these are more likely to affect low engine speed running too.

I get the odd shudder on idle but wouldn't have said I get any problems with low engine speeds. Where are the tumble flaps and how hard are they to inspect?

Also is the temp sensor as easy to replace on the MK5 as it was on the MKIV (when cold obviously)?

I have no idea whether the spark plugs are the correct type, given the oil probably not but they've been pulled at least 3 times in the last 2 months and I'm sure I remember reading somewhere that it's not a good idea to keep removing/re-installing them on these engines.

My invoice does say check spark plus so 'hope' the tech at the stealer that did all the work – this was done pre the compression check. They are the original ones, car has never had them replaced and they are due at the next service.

[Teutonic_Tamer]

I get the odd shudder on idle but wouldn't have said I get any problems with low engine speeds. Where are the tumble flaps and how hard are they to inspect?

The tumble flaps will usually log an error code, so providing the engine ECU scan comes up clear with VCDS, then I wouldn't worry too much.  If you download this link: http://www.golfmkv.com/forums/golfgoodies/mk5golfengine.pdf, it gives you an overview of the engine.  You might like to download all the other related engine manuals as listed in my rather hand 'free workshop manuals' thread: http://www.mk5golfgti.co.uk/forum/index.php/topic,1797.0.html

Also is the temp sensor as easy to replace on the MK5 as it was on the MKIV (when cold obviously)?

I'm not 100% sure - just make sure you change the temp sender on the engine, as the one on the rad won't really help your specific issue.

I have no idea whether the spark plugs are the correct type, given the oil probably not but they've been pulled at least 3 times in the last 2 months and I'm sure I remember reading somewhere that it's not a good idea to keep removing/re-installing them on these engines.

My invoice does say check spark plus so 'hope' the tech at the stealer that did all the work – this was done pre the compression check. They are the original ones, car has never had them replaced and they are due at the next service.

Repeated unscrewing of 'dry' spark plugs from alloy heads will cause 'fretting' - basically the threads in the head start to crack.  A decent anti-seize paste, ideally nickel based, but copper will do - will prevent this cracking.

How many miles has yours done?  The factory fitted plugs were part number 101 905 631 B - which were Bosch F6KPP332S - but these have been superceeded by 06H 905 611 - still made by Bosch, but without any Bosch consumer part numbers.  Official service schedule advice for changing the plugs is 60k miles - but I personally think this is too long.  IMVHO, I'd be wanting to change the plugs at 40k miles - at the absolute max.  I personally change mine every 20k miles - and they are still perfectly serviceable at that distance.