Airbox engine cover flap valve (engine pinking when hot)

Chat about your 9n Polo (inc GT and Fun)
littlepolo
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Re: Airbox engine cover flap valve (engine pinking when hot)

Post by littlepolo » Fri Sep 28, 2012 9:43 am

The No.4 cyl coil that I removed was made in Italy (and dated 2008). The others, and the one I replaced it with are made in Turkey. So I think No. 4 must have been an older coil, and the others possibly replaced earlier. I'll post the codes/details shortly.

I did detect a slight low-level juddering/misfire even after replacing the coil. But after replacing the plugs with new NGK Iridiums, that seems to have gone. The plug gaps had opened up slightly (I'll check them with feeler gauges later - I think its supposed to be 0.9mm, but looks over 1mm), and there was a conical build up of deposits around the electrode. With older plugs a wire brush would have cleaned up such deposits, but not sure about these newer types. Anyway, after nearly 4 years/30,000 miles I think they were due to be replaced. Now running nicely, and with a tank of BP Ultimate I'm setting off for a 400 mile round trip at the weekend.

Old coil:

VW AG 036 905 715G, EE1 S3, ELDOR 7829200, Italy e13 02XXXX, 046F511542/08 0

New coil

VW AG 036 905 715G, EDT S3, ELDOR 78292006, Turkey e13 SKE, 118F51528/12 0

RUM4MO
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Re: Airbox engine cover flap valve (engine pinking when hot)

Post by RUM4MO » Sat Sep 29, 2012 9:17 pm

Hum, historically, these companies move to cheaper places for obvious reasons - and that has caused reliability problems in the past! I hope someone has kept an eye on build quality this time.

Re cleaning plugs, yes that seems to be a "no no" nowadays - at least if using a wire brush, seems that was always not on unless you used a brass brush - I never noticed any problems when I used to use a wire brush years ago.

One thing to watch, maybe get back on to low octane fuel before your next MOT, my wife's car had really good results again this year, expect for the CO level at tick over - that was up to 0.20 from something really low for the past few years - I hope that its down to running fuel that is too high an octane rating and energy rating for the car to optimise the timing on. I seem to remember that your car, at its last MOT was almost on the limit at tick over.

bvs
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Re: Airbox engine cover flap valve (engine pinking when hot)

Post by bvs » Sun Jan 13, 2019 2:13 pm

Sorry to resurrect an old thread but did anybody actually change/fix anything viv a vis the Airbox Warm Air Flap ?
I have gradually improved the power and engine power delivery characteristics on our 1.4 16v manual by doing quite a lot of work over the last 4 years but she still seems to run much nicer in cold weather (yeah I know almost all petrol engines do,but the difference on our Polo is quite marked) and so I got to wondering about the intake/induction air temps.
I came across 2 different forum threads about the Air Box Flap - including this one.
Obviously I am not going to be dismantling anything at this time of year but will deffo have a look in the spring.
Of course in older cars we just used to manually turn the air intake 'trumpet' away from the exhaust manifold for 'cold' air in the summer.

RUM4MO
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Re: Airbox engine cover flap valve (engine pinking when hot)

Post by RUM4MO » Sun Jan 13, 2019 5:11 pm

Was there not a thread or a posting in a thread that suggested buying the thermal capsule from an older Volvo and replacing the one fitted and maybe seized, with that one?

bvs
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Re: Airbox engine cover flap valve (engine pinking when hot)

Post by bvs » Sun Jan 13, 2019 5:20 pm

I have not seen that one Rum - as I posted above - I am merely trying to plan ahead for the spring :)

bvs
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Re: Airbox engine cover flap valve (engine pinking when hot)

Post by bvs » Sun Jan 13, 2019 5:28 pm

This is an interesting little post from sepulchrave on Briskoda
After dismantling the airbox I looked at the problem and scratched my head for a few minutes before I figured out that the small brass canister which controls the flap could be removed and flipped round, so I did this and now my flap too is locked into cold air feed mode.

I haven't had the problems with MAP codes and EPC light that you have, but I have had problems with erratic idle, stalling in town and rough starting when hot which quietens down once at cruising speeds out of town. The car has always started and run perfectly from cold.

RUM4MO
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Re: Airbox engine cover flap valve (engine pinking when hot)

Post by RUM4MO » Sun Jan 13, 2019 5:33 pm

I think that essentially, the air inlet assembly from a 19?? Volvo ???, had a thermal device in it same as Polo, but on the 19?? Volvo ???, you could buy a new thermal device, and it was possible to remove the one fitted to a 9N Polo and replace it with the item sold for fitting to a 19?? Volvo ???.

Just a pity that I could not give better, more complete details of what age and model of Volvo as it seemed that aftermarket parts were still available at least a few years ago. One thing that I never did with my wife's previous 2002 9N Polo 1.4 16V was to examine the cold air flap and check its operation after cleaning things up, by using a freezer spray on the capsule.

Edit:- it could well have been in the Skoda car forum that I read about the alternative source for a replacement capsule.

littlepolo
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Re: Airbox engine cover flap valve (engine pinking when hot)

Post by littlepolo » Sun Jan 13, 2019 6:42 pm

It might seem that I start various jobs and take a long time to get around to completing all of them. But this has to be my record. In tidying the shed just before winter I found the airbox flap valve and started to wonder if putting it back might help improve running (particularly in summer). I think a piece was missing/broken and the job fell to the bottom of the list.

I can't say this posting has encouraged me to do it, but it has reminded me to investigate and fix.

RUM4MO
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Re: Airbox engine cover flap valve (engine pinking when hot)

Post by RUM4MO » Sun Jan 13, 2019 7:15 pm

littlepolo, does the idea of it being possible to get a replacement capsule that fits a Volvo ring any bells to you?

My wife used to start "job" lists for me, but I think that maybe she gave that idea up many years ago - now, should I try to see if I can free up the turntable motor in the microwave oven - maybe, some time.

bvs
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Re: Airbox engine cover flap valve (engine pinking when hot)

Post by bvs » Sun Jan 13, 2019 7:50 pm

RUM4MO wrote:
Sun Jan 13, 2019 5:33 pm
It could well have been in the Skoda car forum that I read about the alternative source for a replacement capsule.
Could well be - I will investigate when I get the time.

rgds baz

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