General Scuttle Drain DIY fix

[tarquin1867]

Just dragged my ageing bones out to the car to finally change the pollen filter. I have taken the opportunity to take a couple of photos of how I have cured the "water in the footwell " problem. It is just a short length of LPG pipe I had over from my old caravan. it fits snugly over the spigot drain and reaches down to the flap valve taking all the water passed the pollen filter. As you may be able to see I used the top right clip on the pollen filter casing to thread a short length of copper wire and twist it up to give some support to the pipe. This has withstood several weeks of me unblocking the hole with an old meat skewer . ( this way of unblocking the hole has in the past resulted in the drain pipe being pushed off the spigot but not any more
By the way - the pollen filter was the original from new!!! and it was marked GM. Just another Vaux**** part found on the old girl.
And before you all get onto me about being a smelly old tw*t --- yes I am:yum: . But the intake behind the original filter is as clean as a new pin and there is absolutely no smell. No need for aerosols of expensive foam to do a cleaning out

 

[s130]

Least you have a top right clip.

Some numpty in the garage broke mine when it was being service by them during the warrant period. I only found out when I did the 4th year service myself!

Anyway some of the pollen filters I have since fitted test to be a little loose in the housing so I put some draught excluder sponge tape on the filter. This gives a nice snug fit and the clip becomes academic.

 

[tarquin1867]

Yes I was very careful in releasing the clips as I had used "search forum" and saw the one which said to watch out for them breaking. The filter I have put in was a good tight fit and had to be pushed in, not so tight as it was distorting the pleats but tighter than the one that came out. I bought it off E-Bay from a place in Mirfield west yorks and I rang them to check the one which it was coming up with on the screen was correct, the chap at the other end said there were several sizes on his screen for the Croma 05/--- only a few mls on some dimensions but enough to give them different part Nos on there system! This may have accounted for your "sloppy fit" in the past

 

[Doofer]

Mine said it was for a Corsa among lots of others. I think they're pretty bog-standard.

I got my latest from the local independent car parts shop. The previous one was from ebay, but I cringed when I saw the postman handing it to me holding it by its edge, inside a plastic bag. Sure enough, it was crushed to death inside the flimsy papery card box it was in. It tried all sorts of bending and stretching but once it's bent it's dead - there was a gap along one end. I left neutral feedback due to the seller's crappy non-packaging.

Don't use cleaner foam - I did recommend it previously but it's a very bad idea, at least in a Croma (or Vectra). The fan spins inside a housing that's basically shaped like a kitchen sink. Any liquid squirted in gathers inside it and runs directly into the bearings and brushes, which are in the equivalent of a plughole. It will smell lovely, then the fan starts making squealing noises, then it stops, then you buy a new one. I did spray some germ-killing Dettol room/fabric spray into the bit that's downstream from the fan while I had it out, and it's been fresh as a daisy ever since.

Oh, and don't leave it so long next time - but you're probably no worse than most. I change mine annually.

 

[Doofer]

I'm going to Tarquinise mine next week. I'll use my old silicone home brew siphon tube, I was due for a new one anyway* - the added bonus it it's clear so I will be able to see how much muck's lodged in it - hopefully none.

I guess the original tube may have started out smooth but has got old, wrinkled and rough like the rest of us over the years. It was always way too small though.

* To bottle my gallon of home-grown blackberry and apple wine, plus two gallons of conference pear and bramley apple, one gallon of banana and one gallon of orange. All bone dry, crystal clear and brain-meltingly strong. I'm just about to have a glass of last year's "Tilt", which is pineapple and grapefruit. All made from clearance fruit from Tesco, when it's 90% off just before they close. Chuck it in the juicer, add sugar and yeast and stand well back. Works out at about 30-40p per 750ml bottle normally, all in.

 

[s130]

I modified my tube/drain a long time ago and every car wash use a fine spray jet pointed directly at the drain hole to flush the bugger out.

However come the next service/pollen filter change I'm thinking about a more radical solution.

a) drill out drain hole to 5 or 10mm
b) hot glue 10 or 15mm U channel to "gutter" water away to a safe drain place.

The other possible alternative is to block the current drain hole and drill one or more drain holes on the other side of the car.

At the moment the current drain hole (when not block) only drains water into the lower scuttle area to be drained out behind the battery. Subject to a more detail inspection any top side drain hole will do the same job as long as it can't drain/drip into the pollen filter/air intake assembly.

Why on earth Fiat/GM designed a 2mm diameter drain hole is totally beyond me. In day of past Fiat would have never done such a dumb design so I can only conclude it is another poor GM design to add to the already poor GM designs that account for 95% plus of the Cromas issues.

 

[Doofer]

There are three possible reasons I can think of why it's so tiny:

1. Designed by idiots
2. To make it discreet and not ruin the look
3. Perhaps there's a risk of it making a humming noise if the hole's too big

I'm wondering if the whole concept's a load of rubbish though - I had a look at my neighbour's small vauxhall and it didn't have anything similar. I think they just design the whole thing to guide the water to somewhere harmless, instead of making a puddle that then needs taking away.

I've got a tyre pump that also comes with a variety of hose adaptors for air beds etc. I was wondering about using one of these as a nozzle glued to the underside of it, with a bigger hole drilled and a length of hosepipe or similar.

I couldn't care less if it's more visible, but I wouldn't want a humming noise. I think it's probably ABS plastic, which can shrug off some types of glue.

 

[tarquin1867]

There was some thought at the design stage because the hole is just at the right place for draining the "trough" when the car is parked at the side of the road, they have allowed for the road camber!
How much testing was done in our "salty" winters (or under trees:yuck I dont know. One thing that stands out is that the cover you have to remove to get at the pollen filter only has a foam gasket to make a seal .
This is worst than useless to keep water in the "Trough" and it can get underneath and probably catch on the lip at the bottom of the pollen filter.
I finished up with a passenger footwell awash due to the original tube being too short and developing a bend pointing towards the pollen filter. My assiduous cleaning only served to put more water onto the filter.
There are two lower flap valves i n the base of the scuttle steel bodywork to get rid of the water make sure you clean these out every time you change the pollen filter, you know it makes sense

 

[Doofer]

There are two lower flap valves i n the base of the scuttle steel bodywork to get rid of the water make sure you clean these out every time you change the pollen filter, you know it makes sense

Tell me more, please. It's a whole new area for me.

I'm wondering whether the original tube is even big enough, even if not blocked. If the car's parked and heavy rain's running down the windscreen then I don't think it would even be capable of shifting the water fast enough. My house is obviously bigger than a car windscreen, but it has a 75mm downpipe, not 3mm.

 

[tarquin1867]

Tell me more, please. It's a whole new area for me.

I'm wondering whether the original tube is even big enough, even if not blocked. If the car's parked and heavy rain's running down the windscreen then I don't think it would even be capable of shifting the water fast enough. My house is obviously bigger than a car windscreen, but it has a 75mm downpipe, not 3mm.

The steelwork at the back of the engine bay forms a box which is covered by the scuttle . Inside this box are the wiper motor and linkages , pollen filter and heater air intake and a sensor for the aircon. if there was no way out for the water we would all get our feet wet!!
In the base of this box are two rubber "flap" valves to release any water which collects to the underside of the car.
Best way to describe them is they are like balloon mouth piece cut off parallel so that the end closes up to a slit while the open end has a double ring which allows it to sit firmly in the hole in the steelwork, which is shaped like a running track. The first time I looked at these both were totally blocked with a foul mixture of sycamore spinners and leaf sepals all bound together with honeydew which is from the greenfly infesting the now -thankfully- gone tree. Had to unblock it with a screwdriver, it was a miracle any water was escaping.
Failing to clean these when you take the scuttle cover off is planning to get a flood!!!

 

[BrianMcL]

Finally took advantage of some dry weather today to have a look at mine and surprise, surprise it was blocked solid. i cleared out the drain hole itself with a long straightened out paperclip and then used the same paperclip to poke both ends of the pipe.

In all the times I've been under the bonnet and changed the pollen filter I'd never even noticed either the drain hole or the pipe.

The hole itself looks a bit too small to stay clear but I really don't understand why the drain tube is so short.

I'm going to get a 50cm length of pipe with a 5mm hole (so that it fits tight onto the existing hole and is long enough to reach through the body to the drain below) tomorrow and that will tick that one off.

Maybe my windscreen won't steam up so much now - it mists up whenever I turn the aircon off so there's clearly moisture somewhere.

 

[tarquin1867]

Finally took advantage of some dry weather today to have a look at mine and surprise, surprise it was blocked solid. i cleared out the drain hole itself with a long straightened out paperclip and then used the same paperclip to poke both ends of the pipe.

In all the times I've been under the bonnet and changed the pollen filter I'd never even noticed either the drain hole or the pipe.

The hole itself looks a bit too small to stay clear but I really don't understand why the drain tube is so short.
Did you poke out the "flap" valves while you were at it?

I'm going to get a 50cm length of pipe with a 5mm hole (so that it fits tight onto the existing hole and is long enough to reach through the body to the drain below) tomorrow and that will tick that one off.

Maybe my windscreen won't steam up so much now - it mists up whenever I turn the aircon off so there's clearly moisture somewhere.

Did you clean out flap valves while you were peering into the abyss that is the scuttle?

 

[BrianMcL]

Hi Tarquin,
I'm not sure what you mean.

There's a rounded off retangular hole in the bottom of bit where the pollen filter and drain tube live. Should there be something in the hole?

 

[tarquin1867]

Hi Tarquin,
I'm not sure what you mean.

There's a rounded off retangular hole in the bottom of bit where the pollen filter and drain tube live. Should there be something in the hole?

Yes , its hard to describe but- there are two of these holes to allow for R/L hand drive bodies.
There should be, what I have previously described as the straight bit for blowing up a balloon with a lip on the end to keep it in place.
The bottom of this is made to close together to keep anything from the underneath of the car out(exhaust gasses and spray) but allows water from the drain /air inlets to drain below.
My mind is racing now, was it you who had the exhaust smell in the cabin on start up? The vacant hole is almost directly above the flexi part of the exhaust.
Have a look at the other side under the scuttle you may be able to see if there is a flap valve on the drivers side which will give you an idea.
Its very strange that you have at least one missing , the top of mine took some getting out to clean as the top lip fits in the hole like a rubber grommet does in an steel electric box . Does this all make sense.
I reckon someone must have taken it out to clean and not put it back properly,(or at all). It may be that if it was put back "loose" it could still be lurking somewhere in the dark recesses of the area under/ around the pollen filter as it would be easy for it to bounce out upwards but it would be very hard for it to have gone the other way and been lost under the car while traveling .
:idea:

 

[Doofer]

I did notice the steaming up in mine for a month or two before the blower fan packed in, so you should notice a huge improvement now you're sorting it, perhaps after a week of drying out.

 

[BrianMcL]

I haven't noticed any exhaust fumes but I'll try and get a picture of the hole so you can see what I'm talking about (in case it's nonsense).

 

[BrianMcL]

If the weather's decent this weekend I might try having a look around the blower unit in case I can see any moisture.

 

[tarquin1867]

Brian- I will take a photo of mine today if I can so you can compare . As you can see from the original post I am no Patrick Lichfield so they will probably be upside down!!
When you stand back and wonder at which frenetic Italian designed that! as I did , you have to think about what has to happen in this scuttle area. Intake air / get rid of water, simple. The flap valve solution is a pretty simple way of allowing this without allowing "stuff" from the under the car to access the inside of the car. It is probably a cheap way as well, but I will bet a bee to a bulls foot if you had to get one from a dealer it would be ~ £20:slayer:

 

[tarquin1867]

Well here goes- got a photo with some of the c**p showing what will happen if you park under a tree.
The rubber flap valve can be seen,just under the bottom of the pollen filter with the red drain pipe going down into it. At least you can see one end of it under the mound of decaying rubbish.

My other post was wrong :bang: there is only one flap valve, on the passenger side , the scuttle is shallower on the drivers side to allow for the master cylinder and steering column etc:doh:.

 

[tarquin1867]

Just noticed that the red pipe is a bit too longand it is holding the bottom o the flap valve open. the grey bit at the bottom of the pipe is the road surface under the car!!! I will shorten it a bit so its just in the top where there is more room and it will still direct the water past the lip on the bottom of the pollen filter frame. This is where the short original tube was directing the water before the fix.