Golf 118 TSI Engine - Revised Spark Plug issued

[Sentinel]

The safe way of gapping these wire tip electrode plugs. Note the comment about breaking the tip if you are rough with them.

That's good to know ... but it seems it would only work with the conventional one-pronged spark plug. Is there an equivalent for the three-pronged spark plugs used in the 118TSI?

That NGK multitool tool shown in the video looks like it might be a possibility - but they don't show how to use it.

I'm having rough idling issues, even after getting new pistons, rings and injectors. The spark plugs are still original, though, and I think they might need to be regapped.

Between the coil pulling, special grease, and the platinum tips, I think maybe I should ask a professional VW tuning workshop to do it. Is that one of the services they offer?

[RW1]

That's good to know ... but it seems it would only work with the conventional one-pronged spark plug. Is there an equivalent for the three-pronged spark plugs used in the 118TSI?

Are you sure this type is fitted?..... odd???

[Sentinel]

Are you sure this type is fitted?..... odd???

No, I'm not.

When I went to talk to my local mechanic (who is not a VW specialist) about spark plug gaps, he showed me a three-pronged platinum plug as an example of the type used in the 118 TSI.

He was mainly talking about how easy it is to damage the tip, but I assumed the VW had three prongs as well.
He might have just grabbed the first platinum plug he saw. I don't know what the actual 118TSI plug looks like.

[RW1]

OK, this is what the old (top left) and new replacement (bottom right) look like. Same apart from the gap is reduced from 0.90mm +/-0.05mm variance to 0.80mm. VW's gap setting is specified as 0.80mm to 0.90mm which in my opinion and useage is too wide.



I replaced mine at 17,127 miles (27,563Km) and three years running as despite cleaning, the plugs had a little misfire in the last 3 months of use noticable at idle, particularly when cold. Shy of 4 years and 60,000Km specified for normal operation/servicing. This what they looked like when they came out.....



The engine runs within Severe Operating Conditions as it does only two 6 mile trips a day generally in urban traffic, both with cold start and the oil rarely exceeds 70'C. The electrode tips were OK but the insulators just not clean.

The gap 0.70mm had been set for the last 6 months of the plug's use, previous to that 0.75mm for 9 months and 0.80mm for 12 months earlier. As originally factory fit supplied, the gaps had been 0.92mm.

Interestingly a Scirocco just two weeks ahead of mine in production had the same plugs gapped at 0.85mm as original fit when I measured them. That varience has been part of VW's 118Kw misfire problems, hence the spark plug revision in 2011 as per this topic.

0.70mm removed all murmuring misfire [no little kicks mostly felt when idling] and no dash indications for the engine. Made a lot of difference to the the way the 7 speed DSG operates as well . Gear change points lowered and clutch switch overs not being felt (seamless).

Change of 4 different petrol brands in the UK over the 17,000 miles did not make any difference to the insulator fouling over time, even with cleaning.

New 03C 905 601A with 0.70mm gap made a continued difference since fitting 2 months ago.

[Sentinel]

Thank you so much for the photos and all the detailed information! Now I have something more to go on.

I've decided to ask a professional to regap my existing plugs, or to install the new ones. I don't have the tools - and frankly, when I used to do all my own mechanical work on a Mini Cooper S motor many years ago, I managed to get a lot of it wrong. The TSI engine is way more complex than that!

Even though it's just come back from a full piston and injector replacement, my 118TSI still idles rough when warm. RPM randomly varies between 600 and 800. Prior to reaching 38,000km, the engine would idle at exactly a little above 700, and never vary at all.

I plan to contact a specialist VW tuner, and ask for my original plugs, from the 2010-built engine to be regapped to 0.7mm. Do you think this is a good idea? Or should I just ask for the new plug version to be fitted?

Again, thank you for all your effort in explaining the issues.

[RW1]

Now you have described the idle speed in more detail, thats not the plugs imo. More like an injector with a wrongly directed output pattern due to blockage. Had one with me to look at like that some 12 months ago and the problem was a bad injector spray pattern.

Give away was the injector in No.1 cylinder was spraying clean the No.1 plug so it looked like it had been in a spark plug cleaning machine when it was extracted. Idle was lumpy as you describe. There were also tell-tale spray wash areas on the piston crown. Question is, did they do all the injectors or has it been an unfortunate repeat (dirty fuel?). Or have you got burnt valves due to the earlier poor injector spray patterns they replaced???

New plugs or old. Given what I have just said, I think they are not the source of the rough engine. Don't know what your driving regime is ie. like mine or open road a lot of the time. If SOC as above yes new, if open road, try re-gapping and see how it goes but note the insulators should be cleaner than my photograph above.

[Sentinel]

The injectors are another possibility. Though I would hope that since they were all replaced under warranty at an authorised VW dealer workshop, they were placed correctly. Nevertheless, I'll keep that possibility in mind.

At the moment, my plan is to get a specialist VW tuner to regap the plugs and check the ECU settings. If there's still a problem, then fixing the injectors would be a warranty issue and I'd take it back to a dealer workshop.

That's mostly because the spark plug option is the easiest - checking the injectors would require removing the engine head (again), as far as I know.

[265coupe]

Is anyone aware if VWA has instructed (by service bulletin) it's dealers to use the updated plugs (03C905601A) during routine servicing plug replacement? And if so do you know when the change occurred?
I had mine serviced in April 2012 (Queensland VW Dealer) and the old plugs (101905626) were used as replacements.
Thanks

[RW1]

Not that I am aware of a bulletin. None has ever been issued. Parts "Alert" not sure.

ETKA - Golf 6 CAVD engine is the revised spark plug 03C905601A. It maybe the dealer had servicing stock on the shelf or the ETKA was misread as the CAXA 90Kw engine on the parts list line immediately above. CAXA still uses the 101905626 plug.

[fillmore]

Just had 60,000km service done and invoice states that 101905626 spark plugs were used. Should I be worried?
To the dealers credit though, as stated on invoice "found loud rattle on start up- found to require cam/shaft adjuster to require strip down and check" to which I must have grown accustomed to. Also "requires clutch kit" and "update (software) required to fix reported pining noise".
Tied up in hospital with broken leg at the moment so will have these issues attended to whilst recovering upon release.

[ope126]

Thanks for all the info in this thread. I will definitely look to get the Spark Plugs changed to 03C905601A (Platinum) or 03C905601B (Iridium / Polo GTI motor?) and check that it is re-gapped from 0.8mm to 0.7mm. I am not experiencing mis-fires, however I am looking at this as a preventative measure.

[ope126]

Thanks for all the info in this thread. I will definitely look to get the Spark Plugs changed to 03C905601A (Platinum) or 03C905601B (Iridium / Polo GTI motor?) and check that it is re-gapped from 0.8mm to 0.7mm. I am not experiencing mis-fires, however I am looking at this as a preventative measure.

Just contacted VW Parts today and they have specified 03C905601B Spark Plugs against my VIN No. They also mentioned that the "B" superceeds the "A" and has nothing to do with Platinum / Iridium?

I will look to change these shortly...

[kazsiddique]

Hey i have the same issue currently on my 118tsi. wondering how u guys went about removing coil pack NO.1 i read that u need to get a coil pack removing tool? screw driver won't cut it??

anyone seen a DIY on these replacement?

kaz

[gavs]

Just contacted VW Parts today and they have specified 03C905601B Spark Plugs against my VIN No. They also mentioned that the "B" superceeds the "A" and has nothing to do with Platinum / Iridium?

I will look to change these shortly...

Just as a follow up to a quite old thread:

The update between the 03C905601A and 03C905601B is the length of the plug.

The issues you have all been describing have nothing to do with the spark plugs, it is the fault of the injectors.

After a considerable amount of time developing a stage 3 tuned Seat running the 1.4TSI engine, another forum member has been through several tear downs and rebuilds with this engine. The reason for the misfiring is because the spray pattern on the injector fouls the spark plug, the spark plug is getting doused in fuel prior to ignition. The reason RW1 has probably seen an improvement by re-gapping their own plugs is because of a shorter, less resistant path for the spark.

The Polo GTI went through an engine facelift which replaced many of the defective parts built into this engine including faulty pistons, leaking injectors, spark plugs that were too long, PCV that didn't really work, oil blow by just to name a few.

Maybe it might be worth those who are having the misfiring issues in their golf 118TSi's to change over to the updated spark plug and see if it has an effect....

[blower]

Just as a follow up to a quite old thread:
The update between the 03C905601A and 03C905601B is the length of the plug.

Not true.....the plugs are the same length (I have both here and have checked).
The only difference between the two is 'A' is platinum and 'B' is iridium.
Both plugs also have the same gap - officially 0.8mm, but they will vary from 0.7 to 0.8mm.

The issues in 2009 & 2010 models with the sparks were the plugs from factory were 101905626 and gapped at 0.9mm - way too big a gap that was prone to misfires. They were platinums and the same length as well.