Plenum Bung Removal !

Thanks for the guide - I'll give it a go when I get some time off.

So what year/models seem to suffer from this?

Yep it affects all years and models. It's also found on Passats/A4s we're sharing the platform with as well.

Thanks for this guide, had water investigation done 3 years ago but they only found bung under the servo, which when cleared, allowed the water to drain. Just had battery changed and plate was removed to reveal this bung, totally blocked with gunge. All clear now but will continue watching for the dreaded water build up....Julian

Is there any risk of disconnecting the battery, regarding radio key / locking the code etc? Im sure Ive read somewhere this doesn't apply to the Exeo stereo system, but thought Id ask

quiggs2001 said:

Is there any risk of disconnecting the battery, regarding radio key / locking the code etc? Im sure Ive read somewhere this doesn't apply to the Exeo stereo system, but thought Id ask

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Hi, there is no problem with the radio code but I was left with the TPMS and the Traction Control light on the dash. Tried turning the steering back and forward but no joy, but drove car a quarter of a mile and two roundabouts and lights were extinguished. You will also have to reset the key fob for the central locking, instructions in the handbook....Julian

julianat57 said:

Hi, there is no problem with the radio code but I was left with the TPMS and the Traction Control light on the dash. Tried turning the steering back and forward but no joy, but drove car a quarter of a mile and two roundabouts and lights were extinguished. You will also have to reset the key fob for the central locking, instructions in the handbook....Julian

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I had this exact fault also. TPMS and traction control lights. I Googled the fault and everything Seat related suggested a long press of the (tyre and exclamation mark) button by the handbrake would reset it. It did but only for a couple of seconds then the lights came straight back on again. Eventually I started the engine and drove just a few feet back then pulled forwards again. Lights went off and no trouble since.

Unfortunately I didn't manage to remove the battery at all to investigate the bung. Had the car for less then a year but after reading all the comments about the plenum bung I decided to check it out. Got the wires off OK but the battery just wouldn't move. Like it was stuck or clamped down but I couldn't see any clamps. Am I missing something glaringly obvious? Cheers.

Big Vinny said:

There is a clamp at the front of the battery base (engine side). It's a bit tricky to get to, it requires a socket with an extension slid in between the battery and the partition piece.

Don't worry about any dashboard lights they turn themselves off after a few hundred yards drive. My key did not need recalibration.

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Thanks Vinny. I'll have another look at weekend.

caldi said:

If I recall correctly its a hex key you need not a socket (or maybe a hex bolt with a hex socket in it)

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It was just a socket when I did mine.

Found it thanks. Will need a hex key on mine.

Just bought my exeo, 12plate facelift. Wondering whether to get this mod done or not and maybe just monitor the situation...oh and not park under any trees lol

I finally got around to this job today (2012 facelift ST 143) and can only add my experience to what has already been said.

Before removal. Everything looked pretty sanitary from on top.



Tools needed were a 10mm, 13mm and a very long 1/4" extension bar (bigger bars wouldn't fit between the bulkhead and the battery to reach the clamp) with a hex socket.



The clamp bolt was located using this bracket and had a circlip around the threads (presumably to keep it all together)



The battery was an extremely tight fit past the plastic scuttle panel but after a fight it eventually came out. 13mm to remove the battery support.



Lo and behold a well and truly blocked plenum bung.





I opted for a compromise on the bung modification. Chopped off half the length which opened it up nicely but still gave any water a direction to flow.





Cleaned everything up and put it all back together. Note that there was not a leaf in sight before of after.



There were a couple of warning lights after reconnecting the battery which went off after driving for a few seconds and I had to reset the remote key fob for the central locking to work again. (Instructions for this are in the owners manual). The clock and date needed resetting too.

Hope this helps.

Just done this on my facelift 143 eco.
Tools required are a 10mm spanner for battery terminals and a long 6mm allen key for battery clamp.
Removing cables was simply enough, REMEMBER TO REMOVE -VE CABLE FIRST
and separate bolted on wires on +ve terminal
Bitch of a job to get to battery clamp, remove rubber seal strip to allow foam covered hoses to be moved out of the way, then wedge a strip of wood about 20mm thick between bulkhead and battery, to push brake lines and thick earth cable against bulkhead to allow allen key into clamp bolt.
Clamp is a 2 part affair with a circlip on bolt threads and a built-in plastic strip to pull it out, if the circlip comes off then you will need to make sure both parts come out and retrieve circlip, refit it to make re-assembly easier
Then pull the battery forwards 10mm to clear the rear lip, and lift the battery out carefully as the foam covered hoses will get in the way, a second person is useful to help here as its heavy
Lastly, use all your keys to open and start the car to re-code the system, drive forwards and back a few yards to re-calibrate the ABS tyre pressure sensors and reset the clock

So I just bought an exeo and looking around it today I found the battery was sat in an inch or so of water. I assume this will be the culprit. There must be 6" of water in places under there.


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caldi said:

Why mess with the battery tray or cutting the bung? there is a large oval grommet that can be removed without taking the tray out, leaves a bigger hole for the leaves to block, if you just cut the duckbill valve it will block again (I talk from experience)

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Caldi, what's the deal with your fix? Seems easier for someone not mechanically minded like me!


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