when driving through the rain on monday i had a few drips on my passenger side matt, in the far left corner.

 

It is not the heater matrix as the drips were pure rain water and the problem hasnt happened before or since. Only when driving through heavy rain.

Just a thought make sure the well under the windscreen wipers is not blocked up, i has that problem with an audi a4 however i had it parked under a tree and the leaves had blocked it, but it could be that. Just take the plastic cover off and make sure the water is not being kept in there (make sure it is draining away ok).

could be drain tube from targa channel; that runs down the A pillar and exits below floor; sometimes splits and you get water inside in extreme conditions.

I had this on drivers side, unfortunately just above fuse box, so had some shorting probs.

this is still happening to me. It seems to be kicking up from the road rather than rain from above and it is getting through to where the ecu sits and caused it to have a funny turn where it was running rough. Dried it out throughly with the missus hairdryer on the cool setting as is fine now (in fact it seems to be performing better than ever before, crud building up on ECU circuit boards over a number of years causes a slight drop in performance??).

 

Any idea how water could be getting through to this area?

Result then!

result and i recomend everyone to have a clean of their ECU and see if it makes a difference, 30 mins job at most.

 

problem is still the water getting in somehow. Cant be good and could cause interior rust not to mention all the elecs round that area.

 

I have tried to waterproof the ecu a bit better by wrapping and taping it up in a tesco bag to stop the water penetrating it (heat build up shouldnt be too excessive and there are ways the heat can escape).

 

where is the water coming from and how can i stop it getting in?????

my bet is still the drain tube from the Targa, pour some water down the hole and see where it comes out or dare I say heater matrix?

Targe Drain Tube or if you have got a boost controler or the car has had one, then the most comon thing is to route the wiring from the ECU harness straight through the Aircon Drain plug vent Grommit into the engine bay. This can dislodge the Aircon drain pipe and it drips onto the ECU. See pic.

 

 

However if the carpet is getting really wet it is most likely to be either the matrix or the Targa Drain cock. You would be suprised howmuch water comes in from a leaking drain cock.

 

The drain runs down the windsreen pillar and down to about the level of the top door hing but about 4" further forward behind the wing. If you open the door and look down there you'll see the rubber out flow. Again sometimes used for passing wires through. The out flow end should point down then the bit that meets the car body acts like a grommit and passes ito the cat forming a seal. Inside the car it then has a 90 bend pointing up and the drain pipe fits into it. If the pipe has come out and the cock is turned. The rain will pi55 in.

thanks mate. A lot to take in there.

 

I found water droplets around the bar that sits above the ECU where there is the patch of rust shown in your picture.

 

Pretty hopefully it is not heater matrix as this incident only happens in really really bad weather.

 

The car does have a boost controller but not installed by myself so dont know the routing through the firewall but thought it went through the other side where the bonnet release cable is.

 

is the air con grommet in the picture as the large looking hole to the right and up of the ECU mounting?

 

I guess my problem is more likely to be the drain cock in that case as the water seemed to be coming more from the left (door side) when it was dripping on the mat.

 

How do i diagnose and fix this? It probably says it all in your post but i am having trouble to picture it without the car infront of me.

 

many thanks for your help.

make sure the air con drain pipe is actually located out of the car which is right near the ECU ;)

 

Vijay

is the air con grommet in the picture as the large looking hole to the right and up of the ECU mounting?

 

No the big hole is where the EFI harness from the ECU goes through the fire wall. The Aircon drian caused the rust on the ECU frame. If you look there is a lable just above the rust and a black grommit just above that. THe Aircon drain should go through that and the grommit has a rubber hose that hangs down the other side of the fire wall.

 

I guess my problem is more likely to be the drain cock in that case as the water seemed to be coming more from the left (door side) when it was dripping on the mat.

 

How do i diagnose and fix this? It probably says it all in your post but i am having trouble to picture it without the car infront of me.

 

many thanks for your help.

 

To sort this you need to remove the glove box, the end cover beneith the dash by the door. The glovebox frame, the ECU cover pannel and the kick plate. You'll then see a white plastic electric plug holder bracket. Unplug the cables and remove the holder. Then remove the rubber that is stuck over the monocock caverty. Whilst you are looking up into the caverty get someone to tip water into the channel at the front of the targa. You'll see the dribble and locate the end of the pipe. Close by you'll see the black rubber 90 elbow the pipe must fit into. Dry the pipe and wait for it to stop dripping. the use a little super glue to ensure it doesn't come out again..

 

Take you about and hour and a half to do job and reinstall.

this is still happening to me. It seems to be kicking up from the road rather than rain from above and it is getting through to where the ecu sits and caused it to have a funny turn where it was running rough. Dried it out throughly with the missus hairdryer on the cool setting as is fine now (in fact it seems to be performing better than ever before, crud building up on ECU circuit boards over a number of years causes a slight drop in performance??).

 

Any idea how water could be getting through to this area?

I`m pretty sure from under sealing mine that there are some rubber grommets in that area have alook behind under and around the splashguard area of the wheel well

Other thing to watch out for is the original seam sealer drying out between the panels, I found a couple of gaps in the sealer when I removed the front wings, right at the base of the pillars, this would likely let water track down the inside of the panels. not sure whether the water would get in to the cabin, but its either that or down into the sills.

thanks for all your help guys. I will try and few of these things and report back.