Gremlins of some description

[ConnorMk6GTI]

Hi guys,
So I've been having these issues for a while now, I will try and condense the prolonged adventure as best I can and hopefully someone can give me some advice from personal experience.

First of all -
- I have an extended warranty so, so far the services have been done at Volkswagen (yes I know) and all within spec to what they want to keep everyone happy.
- I always run BP 98 fuel
- fairly stock, except it has an APR Carbonio carbon fibre intake surround with a pod filter
- pretty positive it has a tune (I'm working on getting the exact details) but I think it has a Stage 1+ (the + being for the intake)

About 4 months or so ago it was very, let's some rough and lumpy on idle, engine was shaking a fair amount and the rev gauge was up and down over a difference of about 200rpm or so.
At first I though engine mounts - apparently not and have had them checked as recently as of Monday - and they are fine.
Coilpacks was VW suggestion - apparently they were fine.
They said "carbon build up" so on so forth, obviously I spat the dummy, went up the chain and even the service manager said no that's not the case. They had a look with a camera etc and there may be a small amount but nothing significant.

To make a log story as short as I can (as I have been to VW so many times the last few months I actually lost track, and dont even get me started on the original guy I was dealing with. I'm now dealing with the service manager only and he is great

THE MAIN POINTS OF INFO:
(This is somewhat intermittent aswell, sometimes it's perfectly fine and other times it has issues and throws an engine light, other times it reports a fault but no engine light, the light also goes away after a while sometimes without clearing it)
So,
- it can be rough on idle and that's all I can really tell
- it keeps reporting
1. Miss on idle - had that code twice
2.rich above idle - had that code once and that didnt throw the light
3.rich in idle - throws that code alot
4. Mass airflow sensor/meter thing (the one behind the intake filter) now that was changed a couple of months ago along with the remaining stock intake pipe into the throttle body - all under warranty
Although it keeps throwing that code and rich on idle on a somewhat regular basis.
Sometimes twice a week, other times it goes a couple of weeks or more with no issues what so ever - apart from the odd slight bumpy feeling when stopped at a set of lights or on start up (whether it be a cold or hot start)

The engine light flashed at me yesterday, which even had VW confused. They looked again today and it threw
Rich on idle
Air flow sensor
And a miss on idle
They cleared it and told me to investigate my tune, so I've done some stops and phone calls today.
I'm currently thinking and hoping it could simply be the plugs (got some feeler gauges and a compression tester today) so I'm looking at them tonight.
Specifications from autobarns system say they are a 0.8mm gap - where as an APR tuner said if they tune it they usually run 0.55mm of gap plugs.
So I will see what hat brings up and I'm planning to run some octane booster through it when I fill up on Wednesday.

Sorry for the massive essay but these gremlins seriously have me and now VW confused.
I was wondering (if you have made it this far) if anyone else has had a similar issue and finally found something so simple that was the cause and the eventual fix.

Any thoughts or help is greatly appreciated as I'm almost to the point of having to spend $100 or so to have it diagnosed by a tuner and see if that shows something, but I'm thinking it may not show anymore than the codes I have been informed of so far.

Again sorry for the massive write up and thank you for reading and thank you more so for any help that you may be able to offer

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[h100vw]

Probably drawing in air after the MAF. If you have the stock intake. Refit it as a test.

[ConnorMk6GTI]

Unfortunately I do not have the factory intake :/

The pipe circled in red is what was replaced at the same time as the MAF I believe. Orignally they thought it may have had a slight crack and was leaking, but when it was pulled off they didnt see any cracks, replaced under warranty anyway because well why not.
I could find the part number possibly if I found the paperwork which is currently buried.
The pipe circled in blue - I'm thinking that wasnt replaced. (Sorry for the dodgey circles, my S pen and screen protector dont get along)
The spring clamps still seem quite tight. Taking these photos earlier I'm thinking I should invest in some quality hose clamps aswell though.


But unfortunately I have no way to fit the stock intake and test it.

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[h100vw]

It would be easy to visually check those 2 pipes. Although without vcds to take some logs you'll not get too far.
Measuring block 032 shows fuel trims. A definitive indicator of air leaks.

[ConnorMk6GTI]

Yes having VCDS would be a huge benefit, unfortunately I do not have access to one currently although I plan to buy one in the near future.

I pulled the spark plugs out today
Vw seems to reccomend gaps of 0.8mm and the local guy that does APR tunes said they generally use gaps of 0.55mm with the tune that I most likely have.
I could only fit the 0.75mm feeler guage in, but I'm thinking they are OEM replacement plugs with alot of build up.
I'll post some photos and let you all have a glance.
I'll be getting new plugs early in the week.
Then go from there

The first three plugs (pictures) are from cylinders 1,2,3 (that's from the cam gear side of the motor in order - not actual piston order) I tried finding the actual numbers for the pistons but I could not. I'm guessing from memory it will go 1,3,2,4 from cam gear onwards, but I could be wrong.
The last 3 photos are all from piston 4 ( the one closest to the passenger side of the vehicle)
I have 150psi compression on all cylinders.

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[manol]

Can't you give your local APR dealer (whoever that is), your VIN and they can see if your car 100% has a tune or not? And if it is tuned, get them to put the car back to stock and see if the issues still occur.

[ConnorMk6GTI]

I have called the local guys, they can search the VIN and see what has been done if and only if they have done the work. Which they have not. I may find out some more info next week and then being able to find who did the tune and then go from there.
Otherwise its $120 just to scan it and see what's been done. And right now I'd rather spend that on new plugs. And to be completely honest I really dont want to go back to a stock tune. I want more power out of it as it is. If that's what has to be done eventually then I guess I will have to, and then more than likely go to a new tuner I found and load up a stage 2 tune. Which apparently their stage 2 tune (with no other mods - I have atleast an intake so I should get some more power) will give me the same power that APR thinks I should have with a stage 1+ tune. So that has me a little confused but I havnt done a whole lot of research into that question as of yet.

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[h100vw]

Software won't fix a hardware problem. Save yourself some money in the long run. Hunt down a secondhand vcds lead or try obd11. It will pay for itself quickly.

[ConnorMk6GTI]

Software won't fix a hardware problem. Save yourself some money in the long run. Hunt down a secondhand vcds lead or try obd11. It will pay for itself quickly.

"Software wont fix a hardware problem."
Pretty much what the guy that does the APR tunes said. Basically it won't be the tune, so that's a good thing

I've been really considering the OBD11, I've heard pretty much only good things about it. As I want/need new headlights soon. Mine have gone very yellow with lots of pitting and some long cracks (the headlight is still sealed, although I did get some moisture in it the other week when we had really bad weather). I'm thinking about the U shaped DRL ones with sequential indicators and projector lenses (which will require coding) I eventually want sequential signal mirrors and taillights too. So the OBD11 was very tempting. I've done a fair amount of research but still cant quite figure out how the Tokens will work in the long run, and I'm pretty sure you can only use it one vehicle, (I have a friend with a mk6 aswell and he knows more people with golfs) so I was thinking about the VCDS cable which you can use on more vehicles, although the long coding on that seems a bit more difficult. Still in the research phase on that one. But one of them is definately on the list to buy very soon.

So first is new plugs, and see how that goes. Then if the codes keep popping up I was thinking about a way to test my PCV. Vw said just keep driving until a hard code pops up. Which if I had OBD11 or VCDS would be fine. But until then I will keep having to go to VW to get the codes checked and cleared to make sure it's not a bad code in the meantime -.-

If anyone has a second hand VCDS please let me know

MY12.5 Golf GTI - limited mods

[maltbbe]

Take this advice with a grain of salt - but you could try hunting for a ‘cloned’ fake VCDS cable on eBay? It’s kind of discouraged on most forums because it takes money away from the people at Ross-Tech who work hard to put the software together - but they’re so cheap it’s hard to see how it’s not worth a shot. I bought a fake ‘Hex-Can’ cable for $30 which came with some cracked VCDS software, and it’s never failed me for everything from logging to long coding. (PM me if you want more info on what I bought &#128077

I haven't tried an OBD11 system, but there's so much support out there for the VCDS software that I reckon a Ross-Tech cable is an essential tool for anyone who owns an old VW. Just a shame they're so expensive!

[Lucas_R]

On the Mk6 GTI, the hard black plastic pipe that runs along the back of the engine bay (the straight piece you have highlighted in blue in your image above) has a connection underneath it for a PCV pipe. I know on a lot of the aftermarket pipes this is known to leak which could cause the symptoms you are having. It might be worth checking this connection is not leaking on your car (or even put some silicone sealant around the connection).

[ConnorMk6GTI]

A Ross-Tech VCDS cable is definately on my Christmas list, and at this stage unfortunately it will more than likely be Christmas before I'll be able to splurge that much on myself/car. But they are definately worth it from what I have heard and read.
Which is why I have been considering some of those cheap dongles off Ebay or an OBDEleven. Fairly inexpensive but will get the job done for the meantime and hopefully keep me out of trouble.
I've managed to narrow down my spark plug options, I'm planning to get some NGK iridium's with the standard 0.8mm gap (the APR guy says they usually gap them at 0.55mm but that's usually for cars running stage 2 with 25psi+ boost. Which I'm pretty sure I'm not running. A friend with a mk6 golf is getting new gauges in the next couple of weeks so I plan to borrow his old one to see just how much boost I am running. But standard gapped plugs should do me and the car a world of good.

As for that pipe circled in blue. I'm fairly certain that it is the original OEM one from factory. I could be wrong how ever I shall try to investigate that when I change my plugs over this week/weekend. I am also thinking my PCV may be on it's way out.
'Apparently' there is not suppose to be any air escaping out the top of the PCV (according to the APR guy) I am yet to ask VW this question, probably a job for tomorrow. Only a very slight amount of air but it does seem strange. Next on my to do list is watch some videos and do some research into checking the PCV is working correctly, and if not hopefully that is covered by my warranty
Please keep in mind that before purchasing my lovely Euro beast, I drove predominantly Jap, so similar workings but there is definitely a difference in machines and their temperamental issues. I seem to be learning all over again. Which I must say I am actually enjoying

MY12.5 Golf GTI - limited mods

[Boordy_23]

I had a scary experience where the mechanic didn't fully engage the spring clip on the hose from the intake manifold to the PCV and it popped off when I gave it some gas. Car started to idle extremely rough, threw engine light and would try to stall on me (DSG model) - when all along it was just the unmetered air.

Have a check for any sort of leak in this area if you haven't already.

Cheers

[maltbbe]

^^ I had a similar experience to this when a plug from my catch can system (on my Mk5) sprung off the intake manifold - which I had originally installed because my PCV valve failed. Since then I've seen a lot of these posts and always assumed it could have something to do with the PCV valve or piping leaking... All the plastic pipes and clips on these systems are pretty rubbish - I've ended up replacing almost all the vacuum lines on the cold side of my engine with a mix of fuel lines with AN fittings, and garden hose with metal clamps. Seems to work alright!

[maltbbe]

On that thought - in the photos on the previous page: what's going on with the rubber hose connected to your intake manifold (the one that runs under the engine cover)? If that hose doesn't have a good seal, it's going to throw all your boost readings off, and could make it run really rough (ask me how I know...)