Plenum drains blocked - a helpfull guide.

[WESTY73]

I always thought my B5 must have unusually good drainage in this area as there was never any visible water in the plenum area.......until I started having issues with intermittently working courtesy lights & decided to get the battery out for a proper look & of course found drain grommets full of evil sludge, guess any standing water was slowly leaking through the sludge between any rain & the times I looked!
I removed the grommet beneath the battery & accidentally pushed the one below the servo down thru the hole where it remains held by the brake pipe as its out of the way & virtually impossible to get back up through the hole without the hands of E.T
Anyway a couple of minor helpful points for complete novices like myself..
1. remove pollen filter top before trying to get battery out, it'll save time & swearing
2. before doing 1^^ remove or at least loosen the small plastic cover on the nearside bonnet hinge as it makes the pollen filter top easier to get off & on
& lastly a question... where do I seal the pollen filter housing? If it's where the top goes on the base, this seems almost impossible to get to the back of, or is it below the plastic box in which the filter sits? in which case the box has to be loosened from inside after taking out the filter, yes?

[Ross 1.8T]

Done mine today. Checked after last nights rain and found about 3 inches of water in the plenum. Its a very good guide but for those of us with B5s, its much easier.

There is no need to remove the battery tray as you can clean out the drain on that side through the hole in the bottom of the battery tray. Also, there is no need to completely remove the corrugated plastic cable duct. Loosening the two clips closest to the passenger side of the car and lifting the passenger side of this ducting up allows more than enough room to remove the battery.

I poked my finger through both drain tubes and they were both blocked solid. I must have had about a gallon of water in there and it came out pretty sharpish too.

Rover 75s suffer from exactly the same problem and the solution there is either to cut the bottom off of the drain tubes or remove them altogether. I've left mine in for the moment but if they block up again in a short space of time, I'll be removing them.

[bobman]

have you alo checked under your passenger side carpet to see if any of it has flooded the ccm

[Ross 1.8T]

have you alo checked under your passenger side carpet to see if any of it has flooded the ccm

I checked all the carpets and none are wet. I haven't noticed any water ingress at all and the car hasn't had any electrical gremlins so I'm hoping its ok. The water was nowhere near high enough to get into the pollen filter housing. My main concern was the ABS master cylinder. Do you think it'd be wise to check it out tomorrow?

[bobman]

never heard of any problems with the master cylinder because of the water,if you wanna check it for peace of mind then go for it, let us know if you find anythin ok

[Ross 1.8T]

never heard of any problems with the master cylinder because of the water,if you wanna check it for peace of mind then go for it, let us know if you find anythin ok

I'll have a look-see tomorrow and report back.

I've heard of ABS cylinders corroding due to immersion before, rare, but an expensive failure for the sake of 15 minutes of preventative maintenance.

[Gary]

never heard of any problems with the master cylinder because of the water,if you wanna check it for peace of mind then go for it, let us know if you find anythin ok

Bob, I think Ross probably means the brake servo as oppose to the master cylinder. When the water gets deep enough in the plenum it can be drawn into the servo by vacuum and it's at this point there can be a massive impact on braking efficiency The effect is a huge increase in effort to move the master cylinder piston, but the cause is water in the servo.

And it doesn't need to be deep to get in the pollen filter. I had an inch in my plenum chamber, but had water ingress into the car. It slooshes around well under normal driving

Gaz

[Ross 1.8T]

The brake servo was indeed the term I was looking for Gary. Getting confuddled with brakes, clutches, zeppelins and suchlike

[subly]

hi...just wanted to know if there is a whole in the boot area doing the same thing...as i hav a stench of bad sock smell in the boot area...
i have cleared the boot area. also valeted the carpet ...buit no joy...seems to go stronger wen the weather is warm...
n no...no socks in the boot either...lol

[mycarsavw]

Usually the foam gasket round the rear lights rots/breaks.

Have a look.

[subly]

will do...once the weather changes again...say prob next yr as brit summer is ova now...lol

[rod the cod]

hi all i went into car this morning and there was about 2 inches of water in driverside footwells.so i removed grommets in bulkhead they were full of poo. but then i noticed about 3 inch puddle between ecu box and inner wing . and a good trickle running inside of car next to were my feet would be . so i poked a heavy duty cable tie under ecu box and the puddle disapeared . then poped hosepipe in and washed loads of poo and twigs out all fine now.. now i just need to dry the car out.

[madrob6]

err, under the ECU box is a gaping hole leading through to all the electrics behind the dash, I wouldn't recommend poking things down there.

[rapidresto]

Just unblocked mine using this guide this morning

Fantastic guide, saved loads of head scratching time! Thank you!

[rod the cod]

err, under the ECU box is a gaping hole leading through to all the electrics behind the dash, I wouldn't recommend poking things down there.

(ERR) there is a channel under ecu box which blocks up which i cleared with a flimsy plastic cable tie.

[marc]

My B5.5 has been smelling of damp for a while and this weekend cleaning out the interior I noticed the carpet in the rear passenger footwell (N/S/R) was saturated. Will have to attempt this tonight or tommorrow as going to France on Saturday for 2 weeks. I hope cleaning the drains will solve this issue. Thanks again for the guide, much appreciated.

EDIT: got the car back last night (Thursday) after it being off the road since I posted above.

I had a quick look at doing this but couldn't remove these clips ? Is there a technique, I couldn't get any movement from them at all?


On the plus side I took out a couple of jam jars worth of leaf mulch from around the pollen filter housing and near the ECU box.

[Jk*]

Just went out to my car and found about 2 inches of what up by the battery. That could be the reason why my central locking isnt working.

I need to wait for the weather to clear up so that i can get them drains cleared!

[Gary]

I had a quick look at doing this but couldn't remove these clips ? Is there a technique, I couldn't get any movement from them at all?

Marc, if you kinda roll the conduit over the top of the firewall edge, you'll see the clips start to slide forward and off the lip as they lift. I'm not sure how strong they are, so what you're trying to do is roll the conduit over just enough for the clip to slide off.

If I were to do it again though, I'd have a bloody good go at reaching the one under the battery tray just by releasing the battery clamp and then getting my hand under it and through the hole in the middle of the battery tray first!

Gaz

[hath]

Just went out to my car and found about 2 inches of what up by the battery. That could be the reason why my central locking isnt working.

I need to wait for the weather to clear up so that i can get them drains cleared!

convenicence t placed under the carpet in a plastic box on the passenger side where u put your feet.. check there get the carpet up a bit slide hte box out.. i have modis at work i can borrow one saturday and come on down chap...>?

[Jk*]

Well after an hour in the pouring rain i have finished cleaning out my Plenum Drains. Needless to say i got very wet, but i couldnt the thought of things getting ruined.

Hardest part was actually get to the drains- im only a small person, so i had to use a screwdriver to poke though the drains to clear them. Oh and those little silver clips didnt come off for me, but i managed to get them off and back on with a bit of encouragement! Was nice to have them all done though but will check again tomorrow especially with the amount of rainfall were having @ the moment.

Also had the Passat on VAGCOM today to and all codes cleared except the c/l has an intermittent problem. A job for another day i guess.

[kirade]

did mine today, the one under the battery was clear, but the one under the brake servo did have some lifeforms in it, and yes mild satisfaction from clearing the bunged up drainage hole

[Jk*]

did mine today, the one under the battery was clear, but the one under the brake servo did have some lifeforms in it, and yes mild satisfaction from clearing the bunged up drainage hole

Sicko!

[Andy N.I]

well well well after the lovely weather we have been having over the last week (NOT), last night i went out to the car a tdi 130 and started it up the outside temp gauge read 0.3 degrees but after a few seconds it started climbing, also when i locked the car i didint get the usual alarm armed flash of the indicators even thought the indicators do work, im puzzelled as to what i need to start looking at except the usual drain problem. I just hop i can get this fixed before it c`auses any serious damage to any of the ecu's

Can anyone point me in the right direction.

Cheers guys
Andy

[Ste_Nova]

cleared mine at the weekend for the 2nd time since the car was new... this time i've removed the gromets completly

[jam69]

I have a similar problem to some of the above, including the sweaty sock smell (from the car not me!). The N/S/R footwell has started to become damp towards the rear edge nearest the seat, all other area's and footwells are fine.

I had a quick look in the scuttle area earlier and it looks dry as a bone, not even the slightest hint of water around the battery. Mine is 2003 B5.5 with a full cover over the scuttle area and an access hatch for the battey terminals (where I just looked through), is it likely to have the drain holes blocked or does the full cover prevent this ?

Is there any other common area for water to get into the passenger side rear footwell ? The inner sill is dry so it's unlikely to be coming in through the door seal or door trim membraine, it just seams to be isolated to the rear area of the footwell.