GT water damage from blocked plenum chamber

GT water damage from blocked plenum chamber

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Hugokirby

Original Poster:

3 posts

132 months

Sunday 30th October 2011
quotequote all
Anyone else had this problem?

My last service (7th annual) they told me I had water under the carpets as a result of the plenum chamber for air con getting blocked with leaves etc and overflowing/leaking into footwell

To fix it they had to dismantle the whole dashboard - £5,000 bill - and then said no longterm issue (see below)

They told me horror stories of similar problems with GT where whole wiring loom had been destroyed and car written off - I got the impression that this was starting to be a regular issue which "no one had known about before" - but seems odd that it's never been checked in the last 7 years?


CONTI T

104 posts

152 months

Sunday 30th October 2011
quotequote all
that is a naughty problem for such a proper car, and yes you would think the price off servicing they could poke out the drain tubes for us...........

AyBee

10,075 posts

184 months

Sunday 30th October 2011
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So £5k bill for you, or wait for something bad to happen and the insurance co. write it off?

R2D3

43 posts

169 months

Thursday 3rd November 2011
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This is without question the Achilles heel of the GT. It is not a matter of if you get the problem but when.
It is all down to very poor design.
The drain for the scuttle area is small and inacessable. It is located unber the plenum chamber and exits over the gaerbox. Almost impossible to see and access.
If leaves and debris are allowed to collect you WILL have a problem. Preventitive maintenance is the key here.I have made a long thin attachment for my vacuum to get into the nicks to remve the debris.
If you see any accumulation of water in the fuse box area under the bonnet--DO something!
I have also found that the lid of the fuse box can distort: its clips will not hold it in place and the seal on its inner surface will fail. For £18.75 + VAT its a no brainer for peace of mind.
Hope this saves someone 5K

Barge Owner

5 posts

126 months

Monday 3rd December 2012
quotequote all
which side of your cockpit filled up? (I've actually had both sides fill up now) Passenger side due to blocked drain, and now the drivers side filled with water.
I have the seat out myself and the carpet is out and drying.
I have to say I have a fantastic garage that helps me out Bowlee Ryan in Kersley off the A666/Stonclough Road.

Barge Owner

5 posts

126 months

Monday 3rd December 2012
quotequote all
which side of your cockpit filled up? (I've actually had both sides fill up now) Passenger side due to blocked drain, and now the drivers side filled with water.
I have the seat out myself and the carpet is out and drying.
I have to say I have a fantastic garage that helps me out Bowlee Ryan in Kersley off the A666/Stonclough Road.

MULLINER

90 posts

175 months

Monday 3rd December 2012
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This is a very common issue on GT as the drain hole is located above the gear box so not easy to clean out. Best advice is to check the compartments in the engine bay and if there is water there immediately dry it out ( wet and dry hoover is good for this ) and coat the interior with some WD40 to prevent damp and corrosion on the ECUs etc which are located in there. and there is no easy DIY way to put a new or alternative drain hole in.

Mulsanneman

6 posts

167 months

Tuesday 4th December 2012
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This is a well known problem. The drain holes in the fuel filler cap well, and the rear spoiler well are also prone to blockage. The advice I have received is to make sure that you have a small bore pipe (old bit of brake pipe) that you can attach to a compressed air supply. Poke this down the drain holes mentioned above, and also take the plastic cover off the front scuttle, and give that area a thorough blasting in the hope that you will get some air down the drain hole below the plenum and unblock it. It is obviously better if you can prevent spiders and vegetation from getting down the drain holes in the first place, so accommodating the car in a garage is also a good idea. Keep a couple of newspapers handy, so that if you spot water in the passenger foot well you can take up the carpet and soak it up.
Good luck,
David.

will_wonka

52 posts

173 months

Tuesday 7th April 2015
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I know this is resurrecting an old thread - but having just got hold of a v low miles GT, I am {probably} being completely OTT in my research and ultimately I ended up here (haven't been on for a while)........

There is mention of the drains for the spoiler area - mine has the water issue which I noticed when I washed at the weekend, it was like floodmybootageddon when I finished and opted to open the boot - water went everywhere !!

I'm guessing the drains are the 2 holes on the bottom of the boot panel?? effectively 2 open rubber grommets (one each side) and one blanked off in the centre.

If they are, I got hold of some strimmer cable (thickish) and went through about 5m in length but could not see where the end was coming out - if anyone has any experience could you advise please smile

I did the filler cap one, but once again could not see where it was coming out - it just ate the strimmer wire by about 3m when I stopped.

Hugokirby

Original Poster:

3 posts

132 months

Tuesday 7th April 2015
quotequote all
HI. Mt post was about the front plenum chamber in front of the dashboard, not the boot (which can be interesting! but not so much of an issue when you know about it)

There's a drain plus somewhere under the dashboard (the service guys know where it is) and it gets blocked with leaves etc. They are supposed to check it every service but I suspect they can't be bothered sometimes as it is tricky to get at.

will_wonka

52 posts

173 months

Tuesday 7th April 2015
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Hugokirby said:
HI. Mt post was about the front plenum chamber in front of the dashboard, not the boot (which can be interesting! but not so much of an issue when you know about it)

There's a drain plus somewhere under the dashboard (the service guys know where it is) and it gets blocked with leaves etc. They are supposed to check it every service but I suspect they can't be bothered sometimes as it is tricky to get at.
Hey! Yes sorry - I saw that but as the guy above me had stated "known issues" which included the boot, I though it apt to see if anyone could tell me exactly where these are.

interesting about the drain plus under the dashboard though - wtf, really? Maybe my investment was not so canny after all. Its done 31k miles (2004 car) with FSH - new gearbox supplied by Bentley at 28k!!!

Any help on the above appreciated.

WelshBentleyBoy

338 posts

181 months

Tuesday 7th April 2015
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It will not help you at all but I had a Ferrari 456 where the aircon would dump half a cup full of cold water over your left foot when you cornered sharply. The answer was poking a wire up some orifice every couple of thousand miles. (Sounds like a visit to a urology department) It did the trick however
Paul

will_wonka

52 posts

173 months

Tuesday 7th April 2015
quotequote all
I'm all for poking orifices if they are (a) appropriate and (b) beneficial to my cause wink

The Benters is like a riddle for seemingly everything, you know the Germans were involved in the engineering for sure frown

Jmorrb

4 posts

90 months

Tuesday 14th April 2015
quotequote all
The two holes in the bottom of the boot lid are the aerofoil/boot drains they block up with crap

Your best bet is to get an airline and blowgun and blow them out allthough it won't always work sometimes you have to take the panel off and clean them out

The drains underneath the scuttle panel which causes the most damage.can be prevented the best thing is to remove them completely because the design is so stupid.if you get a piece of rod(I use welding wire) bend the end into a hook and feed it under the HVAC unit and pop them out or push through

The first one you do is quite awkward but it's worth the struggle

I do them on every service I do now