Blimey… ! Having just bought a MK 2.5 late 2004 and crawling all over it looking for the dreaded rust, that I knew was a problem on these, I was as happy as could be that MINE was all good… Having said that and from what I read here there may be places I missed or couldn’t see… Does anyone know an MX5 expert/ mechanic in or around Bishop’s Stortford, hertfordshire area who would be able to give the whole car a once over before its 6 month warranty expires in July 2016.
Thanks
Rob
Maroon Mica
Don’t get too worried. I had the same worries when I first read this thread but after checking I found very little surface only rust on my front chasis rails.
Start off under the bonnet by feeling underneath and at the side of each side rail with your fingers. (Engine off of course) That will give you a quick indication of any serious rust/bubbling on the rails. If you are still unsure, put the car on ramps at the front and remove the under shield, you can then see clearly for any serious rust. There are a couple of drain holes on the bottom of the rails, put you finger in and feel around. You can shoot some Waxoil/Dinitrol into these holes
Some people have also removed the front bumper and looked into the end of the rails, this is also a good way of Waxoiling the rails if they are fairly rust free.
Fingers crossed yours is OK too.
Do forum regulars and 2.5 owners have a feel for how prolific this is?
Are all cars affected, between what ages, does it depend on mileage?
Are there lots of owners with no rust at all? Or are they blissfully unaware?
Thanks
Hi.
I’m the owner of the Crystal Blue Sport which, unfortunately, featured heavily in this thread.
The tsunami of experiences & activity surrounding the subject has tailed off principally through general public awareness and pragmatic acceptance.
I’ll try and summarise where these cars are today as best I can, and to my best knowledge from several years of experience.
There are many good solid examples around relatively unaffected, and some not affected at all.
Mileage is of no importance. It never seems to have a bearing on good or bad cars.
It seems also Mk2.5’s have a worse name, but Mk2’s are fundamentally the same tubs, and are equally prone.
No singular production run or year has ever been discovered.
There is no scientific or statistical evidence to suggest why this is so in terms of geography, usage, ownership care, overnight storage, attention to maintainance, coastal exposures or any other parameters.
There will be examples in daily use with serious issues of which the owners either do not care, or are technically oblivious/ignorant.
There will be many examples in daily use which range from financially & structurally terminal, to beginning to rot, or which are easily and cheaply sorted with minor fettling.
The difficulty in purchasing a good one, is the required inspection & assurances which ideally require ramping, dropping the engine drip tray out, and trying to figure if rear arch/sill bubbling is minor or well advanced. They rot inside-out and we only see the tip of the icebergs. Usually by the time it’s obvious, it’s expensive.
I would safely wager that 80% or more have issues on the way. Some will be beyond help. Some will only need minor fixing.
Good,solid rot free cars are out there. They are no longer in abundance. Expect to be disappointed going to see a few so called pristine cars.
There are also structural death traps, accidents waiting to happen as ours was 3 years back, passing MOT’s on a monthly basis through ignorance or worse.
However, I may leave it at that since I’ve been told (amongst others) in the past…to “wind my neck in” by a certain “officer” of this esteemed Owners Club.
( I thought about having a “wee chat” with him at the recent Braemar Gathering face to face…then decided what the hell good would it do!
)
At any rate, as medium to long term time passes, the only one we will likely see have either been fettled, or like mine rebuilt to above original quality, or are heated garage queens dripping with Dinitrol etc.
The sooner all the bad ones are gone the better frankly for all involved.
If you are prepared to invest & fix up properly, there can be rewards.
Mine passed it’s MOT yesterday…with no advisories bar a mention the handbrake could do with a click or two dialled up.
All fixed up & rot free for roughly the same as 6 months depreciation on an ND…
Thanks for the detailed reply. I’ve got a couple to look at and will be homing in on rails, sills and arches.
Morgan.
This is a very interesting thread but I try not to read it too much, it makes me question my ownership of the little girl sometimes.
My chassis rails were given the all clear by Rustbuster and I like to have a look around with my inspection camera.
Well this thread is still going strong! I resolved my issues with this little baby below, going on for 3 years almost and it’s been poetry in motion!.…
Having had a great little Mk1 Mx5 and Mk2 chassis rail rot job, making the switch has been a blessing, not a bit of rust on the Z3 which I purchased in 2014, I’ve covered 10,000 happy miles in that time…
Only fair that you change your ID to NOMX5Phill then innit:-)
Haha, I think I’ve earned the right having owned MX5’s for over 14 years!..
This was my old Mk2 RS Sport 6 speed, had it for 9years, shame about the rot though, to think my Mk 1 will out live it.
And here is what will kill it.
I had it patched to get through the MOT, and sold it for £950, welding was visible from inside the engine bay, I consider the repair a temporary solution, though I doubt the value is in the car for a serious repair.
In the end we all lived happy ever after, the Gower lanes have never had it so good with this beauty, and the moral of this story is simple, don’t cheat your customers Mazda with cheap materials and quality control, I voted with my wallet and have never looked back, never buy a Mazda rust bucket again…
In my opinion the car looks great on top but thoroughly neglected down below - lots of rust apart from the obvious corrosion to the chassis legs.
I’m guessing that you are near salt water at Gower?
All repairable - specialist repair sections for the chassis legs and some good old fashioned hard work, along with rust killer, protective paint and underseal for the rest of the car’s underside.
a nice car and a pity you gave up on it.
Yes I have a sea view, and while I agree that can be an issue, my other vehicles are completely rust free underneath, though they are European vehicles (German and French), My sons 2002 Vauxhall/opal Corsa Sri is completely rust free underneath, clearly Mazda are not putting the money into corrosion protection, though having said that my Mk1 MX5 was mint underneath when I sold it, had it for 3 years and looked better protected on the underside, though it was an import. I gave up on the Mk2 because of the cost of repair, plus the value of it had dropped, if I had the use of a garage with ramps etc, I might have given it a serious go. I have restored old classics in the past (MG/Triumph) and I know what is involved for the jobs to be done correctly, and there is great satisfaction in doing so, as long as there is the value in the finished vehicle, but these Mk2 Mx5 have dropped like a stone.
I have just done our 1991 Eunos with a pair of rampettes and jacking the other two wheels up onto six inch blocks. Not much fun I grant you but I now feel a lot better for having got that job out of the way. Just doing the same for the old VW Golf 1.9D(12/96), owned since April 1999 - this was up and down farm tracks as an AI vehicle for the first 2+ years of its life before we made the bad decision to buy it - been hard work keeping the old girl alive ever since.
MK1 cars have very few problems with chassis rail rot. What is the difference between the MK1, MK2 and MK2.5 chassis rails? Whatever the difference it was a regressive move as the MK2.5 seems to be the most prone to issues. All the cars have a similar structure but when I owned a MK2 it did seems to attract more water under the bonnet than the Eunos. I also encounter far more corroded alternators on the MK2/MK2.5 than the MK1.
Anyone technical explain in simple terms the differences in the chassis rail construction/material from MK1 to MK2.5? An engineer customer has a theory that part of the rail is a sandwich of two thin layers of metal glued together but if this were the case welded repair would presumably be impossible.
Mk2/Mk2.5 chassis rails are of a double-skin construction (NCap requirements?) which in time like so many other manufacturers, promotes damp & water retention thereby accelerating internal rot between the skins, eventually erupting when it’s fundamentally to late to do anything other than torch it out and weld.
Or…scrap.
Cross section of my old ones…
I sent a nice piece to Mazda 4 years back.
No reply.
Mk1 rails appear to be of single ( very thick) skin construction and full of factory holes here and there…so seem to breath.
Here is my Mk1 which I still have, which although it needs the usual cills doing, shows essentially mint rails.
These '94 Mk1 photos are a few years old, but they are the same today.
Note the “wax”…factory protection at that.
Notably, my Mk2.5 OEM chassis rails, from Mazda, are very heavy re-enforced single skins…one does wonder.
The finished article
This has been explained in immense detail already within this thread.
At the time of discovering the issues on my Mk2, I had planed on getting one of the very last MK 2.5’s around 2005, but after researching the subject decided better of it, shame that this critical area had been so poorly made and thought out, especially given the high profile marque of the MX5, and it’s following, I suppose for those that have one of the last made, and have undersealed properly, they will have a collectable car eventually.
Well I’m having last minute flap about buying a 2004 Mk2.5 which I have viewed. It is sub 20k miles and shows no outward signs of rust but trawling through this thread makes me uneasy as it appears that low mileage and garaged Mk2.5s can still suffer with the dreaded chassis rail rot.
Other than taking a wheel off, dropping the underside tray and having a prod what could I do to re-assure myself?
I would check its MOT history online to check if corrosion (particularly excessive corrosion) has been mentioned or repairs carried out. That’s what I did when I bought my mk2. Following purchase I then got it MOT’d at a garage I trust to get an in depth assessment. Mine had some surface rust but the chassis rails were solid. I then decided it was worth getting it wax oiled to prolong its life. In summary, be cautious and find out as much as you can before parting with your cash.
Good point about the MOT history… so far that is clear.
When you say yours had surface rust was that on the rails or other areas of the car?
Thanks
Simon