Airbox engine cover flap valve (engine pinking when hot)

[RUM4MO]

Any progress on this issue?

I asked the question about software updates on another VAG forum and it seems that there are quite a few updates around though their individual purpose does not seem to be generally documented.

[littlepolo]

I'm still trying to get connected to the ECU. I'm almost set up. Not sure what I'll be able to see,
but presumably more than the ECU code reader shows me (no codes at present). Of course, now
the weather is cooler, pinking is less of an issue.

I'll report back in a week or two.

If an update were needed, I'd be happy to know that. The engine is shared across Audi/VW/Skoda
so you'd think something concrete would show up?

[RUM4MO]

Even as the weather gets colder, I'm still getting some pinking though if I back off then plant the pedal it disappears until the same conditions are met again.

[littlepolo]

I'm having difficulty finding out which scan tool interface I need. I had an ELM323 interface (has a kind of D shaped plug) that looks like the code reader I keep in the car. But the lug/shape of the plug is slightly off. It will fit, with a shove. I saw some info for ELM323 which says it doesn't work with VW. Any idea which interface I need? I found this on Amazon (cheap enough, but looks very like the ELM323 I have, in terms of shape...):

http://www.amazon.co.uk/OBD2-OBD-II-Cab ... B001C1MNTM

Why would the ELM323 (with software) not work? It seems the Polo (and variants) use ISO protocols....

I think the brake servo is not an issue (re. earlier comment).

As for oil consumption, it seems to vary. In general, it seems more like 1L over 1000-1500 miles. The plugs are light brown, about right, I'd say. But the exhaust can be very slightly sooty. We do a a mix of short journeys, and some 200 mile round trips. In other cars I used to own, the exhaust tail pipe would often be light coloured after a long blast on the motorway - but not the Polo. I cannot see where the oil is going, it seems not to be getting burnt - else the plugs would show it?

[RUM4MO]

There is a shareware version of VCDS, maybe have a look the official rosstec website. On some other VAG forums, seatcupra.net and/or briskoda.net , there has been guidance as to which cheap interface lead can be trusted to be used with this program - I have the full version of VCDS.

If you look in these forums you should find which lead works best, I'll try to look back and see what has been reported in recent weeks.

I do think that the oil is being burned in the cylinders, and yes these newer VAG cars do tend to have slightly sooty exhausts - and like wise, I would suspect, carbonised cylinder head internals. Wife's car is still pinking now and again even when cold and temperatures outside are 8C for instance.

[littlepolo]

Thanks. Forgot to add that its still pinking with this mild weather.

[littlepolo]

I got hold of an OBD II interface that fits, just trying to get it configured to communicate with the ECU from my laptop.

Meanwhile, I found a fairly recent thread concerning an AUDI 1.4 BBY engine, and ECU updates. However, no mention
is made of any pinking problems.

http://www.a2oc.net/forum/showthread.ph ... are-Update

According to that like, the latest soft/firmware is 4MV5949, and the version before that was 5921.

There is a ref. to a German thread:

http://www.a2-freun.de/forum/showthread.php?t=28654

which I'm trying to translate on Google....

[RUM4MO]

Good, at least some progress, sorry for not picking this up sooner. I've ran a full tank of ESSO (normal grade) with a dose of Redex in and it was still pinking while using that tank of dosed fuel. There is some "special" Redex out there but it costs quite a bit. Other ideas/reasons - maybe some cracked crankcase breathing pipes, or gummed up pipes, or gummed up throttle body. I have never, in the 78,000+miles checked or cleaned the throttle body or EGR assembly and pipes. Plugs are correct and still quite new - although as I've said before, this problem was existed for three sets of plugs and two front Lambda probes. Wife just backs off a bit but I tend to back off a bit and then press downa bit more, that usually chases it away for a few miles, but there again I have a manual gearbox and can do that without prompting a change down. I keep meaning to fit VCDS and have a look at some field values when it does this - wife driving of course!

[RUM4MO]

I think that you asked about suitable diagnostic leads that could be cheaply bought for use with VCDS-LITE, well I see that Gendan sell a lead at a reduced price of under £20 delivered (www.gendan.co.uk) - they are a trustworthy company, I bought their VAG scan tool (under £40) a few years ago.

[littlepolo]

Hello, I purchased an ODB interface off Amazon, but could not get it to work on my laptop.
I've just returned it. I'm not sure that would give me an indication of the solution, and I'm
thinking to find an independent VW/Audi garage in the new year and have them do a diagnostic
scan. If it needs a new sensor of some sort, at 50-100 Pounds, or an ECU flash for similar money,
I'd be delighted.

[Dub_Dan]

im not being funny mate why not take it to a vw specialist or local garage if its just for diagnostics youll save some money too!

[littlepolo]

I'm less concerned about spending fifty quid, or whatever, on a good diagnostics, but the potential problem where the garage says 'let's change the sensor' then it doesn't solve the problem, then swap something else, e.g. O2 sensor, throttle body, etc. It sounds like it should be a known problem as other drivers (Audi 1.4 BBY, etc.) have it too. But not a word anywhere on the Internet/Google. Incidentally, only 50K on my Polo, and I've cleaned the throttle body (very slightly gummy) - but not replaced it, or had it re-calibrated. Thanks.

[RUM4MO]

One thing I forgot to add, I've started selecting "instananteous fuel consumption" when I get pinking, and, what I've found at each of the times that I've done this, is that the instantaneous MPG remains at 37>39MPG when pinking is taking place, but when it disappears by releasing and pressing the accelerator further down, the instantaneous MPG does a step change down to 30>31MPG. When covering the same route when pinking does not appear, the instananeous MPG drops gradually from 37>MPG down to 30>31MPG.

[littlepolo]

I do not have the 'computer' display on my Polo. That definitely sounds like its running lean, hence the higher MPG.
Flooring it, changes the revs and fueling - probably coming off lean, and letting more fuel through for the power
demand. That makes it seem more like a mapping / flat spot problem, as we alluded to earlier?

[RUM4MO]

Yes, that was what I was thinking, though you kind of only see what you want to? Either way I think that I need to get going and use the functions on VCDS to do things like check the throttle pedal position sensor - I'd guess that its a resistive strip (potentiometer) - for "dirty" or "non-linear" sections - but maybe even that only happens now and again. Also clean the throttle body, check its movement and check the EGR valve. But the weather is a bit cold and I've never had to take bits of this engine before (except coils, plugs and filter).