Airbox engine cover flap valve (engine pinking when hot)

Chat about your 9n Polo (inc GT and Fun)
littlepolo
Silver Member
Posts: 370
Joined: Thu Jul 21, 2011 9:47 pm

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
Bling Bling Diamond Member
Posts: 4113
Joined: Sat Dec 30, 2006 9:12 pm
Drives: B8 S4 & 6R/6C1 1.2TSI 110
Location: Mid Lothian

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
Silver Member
Posts: 268
Joined: Sat Feb 13, 2016 7:56 am
Drives: 02 1.4s 16v
Location: perth

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
Bling Bling Diamond Member
Posts: 4113
Joined: Sat Dec 30, 2006 9:12 pm
Drives: B8 S4 & 6R/6C1 1.2TSI 110
Location: Mid Lothian

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
Silver Member
Posts: 268
Joined: Sat Feb 13, 2016 7:56 am
Drives: 02 1.4s 16v
Location: perth

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
Silver Member
Posts: 268
Joined: Sat Feb 13, 2016 7:56 am
Drives: 02 1.4s 16v
Location: perth

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
Bling Bling Diamond Member
Posts: 4113
Joined: Sat Dec 30, 2006 9:12 pm
Drives: B8 S4 & 6R/6C1 1.2TSI 110
Location: Mid Lothian

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
Silver Member
Posts: 370
Joined: Thu Jul 21, 2011 9:47 pm

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
Bling Bling Diamond Member
Posts: 4113
Joined: Sat Dec 30, 2006 9:12 pm
Drives: B8 S4 & 6R/6C1 1.2TSI 110
Location: Mid Lothian

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
Silver Member
Posts: 268
Joined: Sat Feb 13, 2016 7:56 am
Drives: 02 1.4s 16v
Location: perth

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

bvs
Silver Member
Posts: 268
Joined: Sat Feb 13, 2016 7:56 am
Drives: 02 1.4s 16v
Location: perth

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

Post by bvs » Mon Feb 25, 2019 5:19 pm

I contacted Wino (Pete) on briskoda and he supplied details about the Volvo part he used to fix the Air Flap capsule.
The capsule part number is Wahler 1266826
But he also said that he would not bother doing it again and the alternative is to push the capsule right 'in' with a screwdriver and then fit a woodscrew down behind it to lock it on the cold air setting.
Another couple of guys have also used their car in sub zero temps and not had a problem,although obviously that is not an exhaustive study of the problem,on aircraft engines one can get venturi icing in fairly warm/humid conditions.But anyway I decided to go the woodscrew route (as in it doesnae cost anything LOL).
This is the pic that Wino supplied.It shows the screw fitted just aft of the capsule and thereby locking it forward into the 'cold' air position for the flap
Air Intake Flap fix.JPG

littlepolo
Silver Member
Posts: 370
Joined: Thu Jul 21, 2011 9:47 pm

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

Post by littlepolo » Tue Feb 26, 2019 9:11 am

That assembly looks different to my BBY.

RUM4MO
Bling Bling Diamond Member
Posts: 4113
Joined: Sat Dec 30, 2006 9:12 pm
Drives: B8 S4 & 6R/6C1 1.2TSI 110
Location: Mid Lothian

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

Post by RUM4MO » Tue Feb 26, 2019 10:04 am

littlepolo wrote:
Tue Feb 26, 2019 9:11 am
That assembly looks different to my BBY.
That picture I think, was taken after the housing was removed from inside the air filter, maybe only early cars had a group of maybe security Torx headed screws fixing that inner cover on to the inside of the top part of the air cleaner, I think that within that thread in Briskoda, someone posted that their air cleaner looked different or had no screws - but the inner mechanism cover was bonded to the inside of the top cover. If that helps at all, if I'm right and it is Torx security screws that were used to secure this small inner cover, then that is exactly what car makers tend to do to minimise the chances of the owner etc removing something that should not need removing, ie not a servicable part in their minds - which is true as VW Group require you to replace the complete air cleaner to fix this issue - which is what lead "wino" on Briskoda to resort to sourcing a suitable part elsewhere, he like lots of us likes to solve problems in an economic and "less waste" way!

bvs
Silver Member
Posts: 268
Joined: Sat Feb 13, 2016 7:56 am
Drives: 02 1.4s 16v
Location: perth

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

Post by bvs » Tue Feb 26, 2019 11:18 am

littlepolo wrote:
Tue Feb 26, 2019 9:11 am
That assembly looks different to my BBY.
Sorry LP - yes this pic was taken on the inside of an engine cover of a different engine code - with the air filter cover + filter removed (Fabia 1.2 I think).
It is very similar though to the AUB engine cover/air flap design,the only real difference on our engine is that there is a vertical support on the underside of the capsule housing.On ours I enlisted the help of the boss - she held the capsule right forward (away from us) with a screwdriver (strong spring to overcome) and there was just room to drill through behind the capsule and then fit a screw to 'trap' the capsule full forward (ie towards the front of the car).
I will try the car out tomorrow and report back here :)
Last edited by bvs on Tue Feb 26, 2019 11:21 am, edited 1 time in total.

bvs
Silver Member
Posts: 268
Joined: Sat Feb 13, 2016 7:56 am
Drives: 02 1.4s 16v
Location: perth

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

Post by bvs » Tue Feb 26, 2019 11:21 am

Just to clarify that we only had to remove the (11 ?) normal cross head air filter access screws,no need to touch the torx type screws attaching the air intake 'trumpet/duct' to the front edge of the engine cover.

Post Reply