A Long Night of rain - Mk1 Mx5 leaking

Technical Area Body, Interior & Styling
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Hi guys I’ve got a 1992 1.6 Eunos Roadster.

As people in the South East will know there’s been a significant amount of rain come down over the last few weeks. I have been using my Mx-5 a few times a week and over the last few days I’ve noticed there’s a significant amount of condensation within the car (on the inside of the windows, a couple of drips on the centre console and on the inside of the drivers door (especially right at the front by the steering column)).

Having had a prod around what I’ve found is that the driver’s side footwell is very wet, there was what was starting to become a puddle in the footwell, the drivers foot mat was soaked through and the carpet underneath was very wet too. I have removed the mat and hung it up to dry, as well as dried the carpet as much as possible with a towel, but I’m wondering what will have caused water to come up there? its not in the passenger side really (maybe a bit of moisture) - is it a drain hole that’s clogged up or a leak in the roof somewhere? Any thoughts appreciated…

Also, not sure if its related or not, but I’m sure its only come around as winter and rain has started, but there is now a continuous white mark across the very front of my soft top (I will try to attach a photo), and I have no idea what this is or how I can remove it?

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Lastly, another thing I noticed was the door lock from the outside on the passenger side is really stiff now, I wouldn’t want to try and lock it now from the outside because I worry I would snap the key, any suggestions of a way to loosen it up.

Sorry its such a long post, anyone who has got this far, thank you and any recommendations or thoughts would be very much appreciated.

Nathan.

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On an NC it would be a failed gasket that seals the inserts that the scuttle cover screws into.
On yours I would personally be looking for blocked scuttle drains where the heater draws in fresh air.
If the drains get blocked with debris, water can’t drain away and flows into the car through the heater.
Happens to the wife’s Panda frequently.
For the lock, any spray lubricant, preferably with a straw.
Another way is to oil the key and keep easing it in and out with more oil and then turning it gently with more oil to free it up and lubricate it

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There is a little rubber cup and the top of the A post, this is designed to catch any water the makes its way past the roof/door/A post joint and channel it down though the rubber seal on the A post to the bottom of the door. Pour a small amount of water in and check that it drains out.

The white mark just looks like sun fading from having the roof folded with no tonneau cover fitted.

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The A-piller drain was enlarged on the Mk2, so Mazda found it was clearly inadequate for the job. The drain tube is flattened with the door is shut; a dumb design.

But given the amount of fading on that roof, I would not be surprised, if it is a vinyl roof, its shrunk over the doors. ie. the roof is getting to the end of its life. If a cloth roof, the rubber layer is rotting, and the hood needs reproofing The end of the

For the door lock, don’t use WD40. Shoving lubricant into the lock only lubricates the brass leaves on the barrel. The end of the lock barrel has a cam, that actuates a rod when turned, to lock/unlock the door. I have seen this wear, with the result of the lock barel being scrap.

Its possible that you need to lubricate the rest of the mechanism. Take off the door card to investigate.

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Agreed.

After a few days WD40 turns to a gluey stiff wax that is difficult to shift!
It isn’t a lubricant, especially not on delicate stuff.

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Okay, can you recommend a good alternative as I don’t really have a clue?

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is it your opinion too that the sun fading means its time to go for the hood - and that its likely shrunk to cause the leak?

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Okay thanks or that, will have a more in depth look

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Almost anything is better!

WD40 is designed to stick very well and provide a protective water-proof film, it was brilliant in the 1960s on old fashioned Mini distributors and spark leads.

Once the dreaded WD40 has set in such a confined space as a lock barrel you’ll then need lots of plus gas or brake cleaner or isopropyl to dissolve and rinse it out; it all become very messy, and if you use plus gas then that also needs to be rinsed out. In some past cases when I was presented with a lock gummed solid with repeated winter morning doses of WD40 it was quicker and easier to simply replace the barrel.

However, for sticky locks I normally use Servisol Super 10 Contact Cleaner, mainly because the mechanism in a small lock uses very similar metals to switch contacts (which tarnish/corrode in similar fashion), and best of all this particular contact cleaner leaves a very thin permanent lubricating film. Unfortunately it cannot prevent an old lock with a broken shutter from filling with water and freezing solid, here a new barrel is needed.

This illustrates one of the arguments for having remote-control push-button central locking! (But NOT modern insecure walk-up proximity un-locking!)

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Hi Rich, thanks for your advice I purchased some of the Servisol Super 10. In terms of application, I put the key slightly in (to move the shutter across) and then sprayed into the key hole. I then left it for 24 hours or so before trying with the key and it still feels very stiff, in fact I might argue it was harder to get the key actually into the hole this morning than it was previously, have I applied it wrong or should I try another layer?

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Not 24 hours!

It’s best to give it about ten to fifteen seconds, then gently, gently exercise it with the key to work the solution around and penetrate to the jammed bits. Then a minute or two later repeat this, and maybe a couple of times again especially if you can feel positive progress each time. Be sparing and patient with each application. The chemistry can take anything from a few seconds to a few minutes depending on the degree of contamination.

The idea is to a) release the crud, b) wash it away. This is unlikely to happen in one go, hence a couple of tries or more.

If it stiffens up after becoming free, that’s because some of the sediment remains trapped somewhere and once the carrier has gone it will set again. A thorough rinse with Isopropyl immediately, before the Servisol carrier evaporates, will help rinse out sediment, and the great advantage of the Isopropyl is that it all evaporates afterwards. I would then finish off with just a final light touch of Servisol to protect the lock once it is properly free.

However, if there is mechanical damage or it is badly worn, as saz9961 mentioned, then a couple of squirts are not the answer. And by now damage is quite possibly the problem, hence why we often just replaced an aged lock, or swapped it with the one from the passenger door where possible!

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Okay will have another try

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Is the key original? Possible that a badly cut key is stiff to turn.

The lock barrel is fitted with sprung brass leaves, which are matched to the key. When the key is inserted, the leaves, or wafers (its called a wafer lock) will retract, allowing the lock barrel to turn in the lock cylinder and allow you to lock/unlock. The lock cylinder itself (well that’s what I call it) doesn’t need lubricating. If the key hasn’t been cut well, its possible that not all the leaves/wafers retract, and the stiffness is the leaf catching on the lock cylinder.

If you take apart the lock, with the lock inserted into the barrel, you can take a file to the offending leaves (if this is the issue), or even just pull out the leaf (you can also transfer leaves, in order, to a used lock, to reset it to take the original key).

Basic steps to remove the door lock, but not to remove the lock barrel:

And also here:

https://www.miata.net/garage/lock_core.html

Assembled lock cylinder (I may have the incorrect terminology)

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NA MX5 lock barrel and dissambled. Note, each eafer also has a tiny spring

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From: Blog George Timmermans - George timmermans

If you do this, work on a sheet of white paper. Its easy to lose parts

Other useful photos

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This shows the little sprung flap removed. The flap is essential to stopping ■■■■ getting into the lock. The spring can break, but in other locks, I have seen the casting of the cylinder broken, rpbably by someone trying to force a lock.

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Lock barrels. The cap at the end can wear, rendering the locks useless (the lock turns, but doesn’t lock, unlock reliably)

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So when you remove a lock cylinder from a door handle (see the MazdaMender video), the lock is attached to an arm. To strip it all down, you need to pop off the circlip (I pryed it off with a screwdriver)

You also see on the arm a little lump of metal that can wear away.

2 Likes
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The key is not original, but the problem has worsened over time, also having lubricated it up I could get it to at least turn about 2/3 times the key was inserted, when the lock did turn, it sounded and felt almost gritty (that kind of sandy sound), which leads me to believe it might be just dirt that needs removing.

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Keys do wear. It might be dirt, might be bits of metal. If there is dirt, try compressed air. If that doesn’t work, strip down the lock.

2 Likes
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Late to the party lol
M-m