Bought my MX5 Mk2 in April, it’s weathered some heavy rains but there were no water problems until this month. After a particularly rainy night, I found that the carpet behind and under the passenger seat were wet. Nowhere else. This was a couple of weeks ago, I figured it was a blocked drain, so I cleaned the roof drainholes with a trombone cleaner. A little bit of dirt came out, but it didn’t look like enough to be completely blocking the drainhole. Unfortunately, I have no means to take out the seat, so I just left the top off in the sun, which dried out the carpet behind the seat. I also lifted the behind-seat carpet so soundproofing could dry out. The carpet underneath the seat dried too, but I couldn’t properly get under it - I dried the best I could using towels but there was still some water underneath the carpet, and the soundproofing was soaked. Since then, I’ve consistently been getting water ONLY underneath the carpet under passenger seat. Behind the seat (including under the carpet) is dry, and the carpet under the seat is dry, it’s just that when I shove my hand under the carpet I can feel the damp. I can also feel the wet squish of soundproofing in the footwell area. But, as I say, the carpet is not wet on the outside. I am at my wits’ end -I don’t understand where the water is coming from. I’ve tried looking everywhere for answers, but people tend to have a wet carpet problem, not a wet under carpet. Can anyone help please? Thanks!
A couple of years ago my BM 840 had saturated carpets - no sign of where the water was coming from.
Turned out the screen was leaking - the water ran down behind the dashboard, down the firewall behind the carpet, out of sight, and collected in the footwell.
Sound deadening material beneath the carpet was saturated but carpet upper surface was dry!
I’d be pulling up the carpets and looking for water marks…
(In the BM there’s a computer for the antilock brakes down there - it was just a rusty mess by the time I realised - a few hundred quid out the window…)
I had this problem once in our Mk2.5. It was probably after about 8 years, and passenger side only. Took the seat out and got all the carpet up, (soundproofing soaked). Got it dry then put everything back. Could not see any obvious reasons for the leak. I cleaned out the drain holes but nothing obvious. Never happened again? (recently just sold at 17 years old). We did eventually replace replace the hood, but I am sure that was much later? Perhaps we left the widow down a little?..never really found out…
On the plus side it is very easy to remove the seats (4 bolts and the heated seat connector)…
I had a leaky rain rail on a Mk1, same on the Mk2’s the leak could be running under rear deck carpet and down into the footwell. I would be peeling back that carpet behind the seats on the rear deck and having a look see.
To the original poster, you need a loan of a 14mm socket, a socket extension and a long socket bar to lossen the bolts the first time. Put a touch, no a lot of grease on the threads and after that a 14mm ring spanner will do the job like this, not what is called a combination spanner.
Thanks - taking the seat out and drying it all out would be ideal… However, I don’t gave a garage, not even a driveway - I park my car on a side street where I need to walk for 5 minutes to even get to my car… So taking out the seat is kind of hard. I actually asked at my local garage if they would take the seat out and they flat out refused looking into garages specialising in mX5s now.
Thanks - I did peel the rear deck carpet back, it’s dry under but will maybe sit in the car while it’s raining/ after pouring some water to see if the water’s coming through there…
You need to get the passenger side carpet up as soon as possible and dry everything out.
The sill protector need to be manhandled(ripped up) to be removed and then the carpet will fold back sufficiently without removing the seat.
Get the protector plate off - three 10mm fixings at the top and two security fixings at the base - these will need to be shocked loose with an old screwdriver or chisel and hammer.
Do not leave this and expect the water to evaporate or drain away - it will sit in the soundproofing held in by the superior carpet. The damp will rot your ecu and cause you a non start and expense.
Please get this sorted today.
I sell the ecu/immobiliser kits to replace water damaged, etc and it has been quite busy over the last 6 years or so - Much as I would like to take your money and help you should the worst have happened, it would be far better avoided.
Water ingress in the MK2 is most often the drains from the roof behind the seats. Perhaps something has dropped into the tube and seriously limited its water evacuation potential. As you already no doubt know the best way to test these is volume test with a funnel and watering can. Water should pour from the tubes at a healthy rate. If it is looking a bit lacklustre there will be a partial blockage.
Hi, thanks for advice. This does seem pretty urgent. The first leak happened just over two weeks ago, so I’m hoping it’s not too late! I just arranged to use someone’s driveway, so will take the seat out this Sunday. Is it likely that there will be water under the ECU protector plate?
It depends how much water has got into the car but with road camber and vehicle parked facing downhill, the water will flow through bulkheads into the passenger footwell.
I would not start the car as if there is sufficient water you could cause a short on the ECU PCB.
The immediate concern is preserving the ecu, so do not initially worry about the seat, just lift the footwell carpet as described, remove the cover plate and dry out that ecu. With the carpet lifted, the carpet and sound proofing will quickly dry out.
The ECU has 4 bolts that secure a mild steel backplate and a similar fifth bolt that holds the PCB in place in the ECU case. Check the ECU pins where the three plugs connect - these should all look shiny with no corrosion or milky appearance.
Just thought I’d write an update. I managed to get the seat out and lift the carpet. As I had suspected, the soundproofing was all soaked and holding a lot water. Thankfully, the ECU (and area around it) was completely dry, there just wasn’t enough water to reach it. I poured quite a bit of water on the car to see if I could spot water collecting anywhere, but there was nothing (apart from a couple of drops by the window). I ripped the soundproofing from the carpet (it was barely holding on anyways) wrung it out and dried it out, then put it back in. For the moment, I’m keeping my car under a waterproof cover when I’m not driving it, as I’m traveling in september and don’t really have time to deal with this again. I’m hoping it might have been a one time thing - the drain tube must have been a little blocked up and couldn’t handle the volume of water going through it in the very heavy rain, and water backed up into the interior. The real test will be after I come back in October!
looking into garages specialising in mX5s now.