2018 ND leaking again!

Technical Area Body, Interior & Styling
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  1. My model of MX-5 is: ND1
  2. I’m based near: Stirling
  3. I’m looking for technical help or recommendations on: water ingress

After an exceptionally heavy downpour, think biblical, I’ve just noticed my windows streaming up, again!

This happened a few months ago and I stripped the interior and checked the filters behind the seats but everything was fine and nothing obviously blocked.

The carpet is wet behind the driver’s seat (UK) up against the centre console. That, I believe, means that it’s probably coming in behind the passenger seat.

Is this something I’m just going to have to put up with? There’s not a problem with ordinary rain, just the real heavy cloud bursts. I’m loathed to stick my trombone cleaner down these silly plastic drains as I’m worried that I’ll do more harm than good.

The only thing i can think is that further down the drains there may be a slight blockage, or is it just the case that all our cars leak occasionally in very heavy rain as the drains can’t cope?

Beginning to think I’m just going to have to put a cover over it…

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Can’t see using the trombone cleaner causing any harm as long as you only use it in one direction. This means getting on the ground and pulling the cleaner though once it exits the car. If you pull it back from the position you put it in, it will probably foul on the one-way valves.
In early NC’s the entry hole was not covered with a grill. Then they added a grill. Now with the ND1 there is no grill again?

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Thanks Beryl.

I’ve owned an NA and an NB2, and cleaning their drains was very straightfoward, as you suggest. I’m not even sure that it’s possible to feed the trombone cleaner through the ND drains, hopefully someone can advise.

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I have an ND2 and removed all the trim behind the seats to get to the lower tube of the drain system.
This is behind an oval trim panel quite low down behind the seats.
There was no way the trombone cleaner wire was getting through that as the near 120° bend of the tube makes it nigh impossible.
I’ve read on here that there is a flap underneath the car that is a 1 way flap so you shouldn’t really go upwards through the drain hole.

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Thanks 787. So what did you do when you removed the panels? How did you clean the drain/remove any blockage?

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I managed to get the trombone cleaner as far as the bend in the tube, there was nothing on the brush (dirt,leaves etc) so I’ve left it there. The tube join is quite high up and I can’t see how to remove it so have left it .
There was a couple of drops of water on the floor in that area where you can see the tube but seeing as I had just hosed down the roof, I put it down to that.
To get the trombone wire to go down, I did the trick of fully unwinding the seatbelts to get access to the drain hole behind the seatbelt reel.
When I run the hose on the roof I do get clear runs of water just in front of the rear wheels, but cannot see how to remove that bended tube

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More info here

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Thanks 787, much appreciated.

These drains really are awful, whereas the NA and NB were straightforward. I removed those two panels last time but didn’t remove the drains.

I genuinely don’t think my drains are blocked, i actually think the rain rail behind the seats can’t cope with very heavy rain, causing it to occasionally overflow.

I don’t think there’s a solution and that it’s something im just going to have to live with.

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When my drain (driver side) was blocked I separated the two parts of the drain, in the hole behind the seats. It takes a few trim pieces removed to get there. Then you can run the trombone cleaner through both pieces easier. It is a lot of work but I prefer that rather than a lake in my foot well.

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If you have a compressor with a pistol attachment, would it be possible to use that to clear any blockage in the drain pipe?

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Thanks folks.

YoanH, I’ve take it apart before so that’s okay, it’s just handling the actual drainpipe i worry about.

I may separate the drain in the panels behind the seats, then try pouring some water on the hood and see if it reaches where I’ve separated the upper and lower parts. I can then rod downwards with the cleaner.

Did your trombone cleaner feed up and down from there okay?

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Good idea mxomatosis, but i have neither of those items unfortunately.

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To save repetition, have a look at this thread.

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Yes, the pipe without the rubber flap you can pull in both directions. For the other pipe that has the rubber flap only go in the direction of how the water would flow - aka down towards the ground.

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Cheers guys, much appreciated.

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There are filters on the ND which get clogged up with leaf debris, so don’t park under trees! When it happened to my 2021 car last year the dealer said bring it in and we’ll clean the drains under warranty (which they are not obliged to do, so that was good of them). They showed me photos they’d taken of the clogged filters.
It’s a pig of a job and it helps to be young and agile to do it (I’m neither) so I’ll get the dealer to do it every 2nd annual service.

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To stop leaves etc. getting into the car’s roof drains I would get a half cover. This stops all the debris getting into the roof drains when the car is parked. Mine is parked outside close to my house and the birds are constantly throwing moss etc. on to my car when looking for insects in the house gutters.

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18

Thanks Vinny1 and First_rider.

The thing is, my car has never been under trees. It was garaged until a couple of years ago and now lives on my drive with no trees nearby. My filters have been checked by me, twice, and are clear.

I’ve had an NA, an NB2 and now my ND1 and all three have leaked at some point. It was clogged drains in the NA and NB, but with my ND it appears to be that on two occasions, albeit in 3 years of sitting on the drive, the drains just haven’t coped with two truly biblical rain storms.

I now have a half cover, reinforced with fabsil gold, and this has kept the car, and roof, completely dry over the last few days when we’ve had very heavy rain.

I’ve copied a previous poster, and put pool noodles, cut horizontally through the middle to lower them slightly, across the roof and down the rear screen, this lifts the cover off touching surfaces and creates an air gap.

All now well, no water ingress, and now no stress during torrential downpours. None of this should longer be necessary in modern soft tops, yet here we are, the problems from days gone by still persists today, who’d have thought…

My cover was from UK Custom Covers. I’d recommend, albeit did need more weatherproofing, and a door tag for securing in one of the doors was missing. However, it’s a tight fit all round on the ND, and is still secured via three door tags, two boot tags, two door mirror straps, and the wipers. Cost about £70, but has done the job with the Fabsil sprayed/painted on.