MK2.5 owners, check your front chassis rails

Important topic, please let’s keep it factual and not fall out about the differences between the MK2 (and sub versions) where there is plenty of evidence of an issue and the MK3 (and sub versions) which may contain similar design characteristics but which has not yet shown evidence of the same problems.

I sold my MK 2.5 at 4 1/2 years with bubbles appearing in the quarter panel in front of the rear wheels. My MK3 is 6 1/2 years old and apart from surface rust on chassis parts is showing no other signs of rot. It gets a pit inspection twice yearly.

I managed to gather some pictures of my “misfortune” Embarassed first pics are engine rails rust. They are on picassa, dont kill me for that… Stick Tongue Out

https://picasaweb.google.com/110559675572744655988/MX5Restoration?authuser=0&feat=directlink

Does anyone know whats that material showing underneath grinded outer rail??? Huh?

 

 

Great pics, https://picasaweb.google.com/110559675572744655988/MX5Restoration

The metal is steel and the thin stuff may be aluminised or maybe galvanised steel if it has a silver coloured coating.

How did you get the pics inside the rails? Are they from a probe or is the end of the rail open?

I’m being good Ian.Big Smile Wink

 

Thats easy… take off bumper reinforcement and unbolt that metal guide/plate with nose on top. this reveals pretty good hole You can inspect inside with torch or even get in wire brush with some extension to treat surface rust if necessary. :slight_smile:

But i strongly doubt its metal as grinding it does not produce sparks, it is tough though, and breaks apart to pieces around holes. I ain’t got a freaking clue what that can be and if it is meant to be there… Confused

oh and thanks for improving my link. i aint good at this forum functions… Smile

Rich, All and with respect to IanH’ statement/request.

I agree with the statement about corrosion warranties to a point full of get
outs and caveats, it is after all a perforation only on body panels warranty
and then only if annually inspected by an appointed dealership, with stone chips requiring
instant attention etc etc, yes, comparable with other manufacturers warranties
on bodywork, aka, useless to you and me.

Although a clean sheet design, the actual construction of the shell is very
similar to the Mk2/2.5s with the exception of some so called “high strength”
steels. This is a minefield in itself as many misunderstand just what this
means. Mazda promote this material as a high tensile steel, fantastic when the
steel is in a tensile state but what about under compression? High strength in
tensile can often mean the complete opposite in compression, perhaps this is
useful in crumple zones to acquire the required shock absorption under impact to meet crash test standards.
Also bear in mind Mazda are using so called high strength steels in order to
make weight savings to improve emissions. These are in the main not overly exotic steels but a fiddle about with a few basic additives and the appropriate heat treatment will result in thinner steels with the same strength ergo, thinner sections can be used to make weight losses. Let’s not kid ourselves that this is
because they want our cars to be lighter for any kind of consumer matters, this
is purely emission driven because of fuel costs (governments lead this issue)
and vehicle tax, again a government led issue, squeeze the motorist dry and then
some more.

I also agree that it is perhaps not fair for an amateur to make assumptions
on looks alone. Thankfully as a qualified engineer, starting as an apprentice,
working on the tools for a good number of years, returning to college to get
some further engineering qualifications and moving on to project management and
subsequently a whole host of other engineering disciplines in a multi
disciplined engineering environment for some 35 years. So, fair to say that I
have a little experience in understanding some basics of design and materials.

In fairness the other issues raised by SF although not directly related are
showing that there are some growing concerns about the quality of the MX5 in
its current state, as you will see by my previous posts my very well cared for
2010 RC has a number of niggles, some have been warranty addressed, some others
such as the stupidly soft paint used by Mazda are being looked at directly by
MMUK. My front bumper is already in need of a respray due to the amount of
chipping on the paint, totally unacceptable on a car of its age and mileage, in
fact as a very keen and hopefully competent detailer it is fair to say that the
paint is generally in a poor condition due to scratching and chipping and I am
certainly not a tailgate hugger nor do I do vast mileages on motorways, a
couple of 1000 mile round trips via the M6 in the year other than that mostly
good A roads and of course some of the stunning B roads I have access to in my
locality. I am simply saying that the Mk3 and 3.5 are not perfect and if they
have these well documented niggles who is to say that tin worm might not be on
the horizon by the time they are drawing their pension at 10 yrs old? I s a car year equivalent to 6.6 human years?

As for having a go at Mazda, well, actually yes, I think someone needs to be
pushing them hard on a number of issues, least of all, not so old, 10 year old
cars becoming death traps and that is the reality of this situation, some of
these cars will crumble in a minor shunt. There is no manufacturer on today’s
market that should have been producing cars that rot to this extent in the last
20 years let alone a mere 10. Lancia taught the motor industry many a lesson
and that is why there are now so many cars of 20 years plus still sailing
through MOTs on a regular basis

Damn sure I’d be annoyed at Mazda for selling me a car that turns to dust and
a potential killer after 10 years! As far as actual £££££s on paper value, well
that’s a very subjective thing isn’t it. We just traded in a 5 year old Focus
in order to downsize my wife’s car, the best trade in we could muster,
£3600,  this was an immaculate car, FSH and
35k miles, had we not been in the market for downsizing to make long term
savings then what was the worth of this car to us? Who can tell, it is as I say
subjective  and as such I think it is
very unfair to attempt to put a value on a cherished motor car. The head would
perhaps say, get rid, get another one but you cannot equate that to what you
might be buying, SF knows the history of their sport and it is extremely sound
mechanically, who is to say that if you get rid of one to buy another you may
end up being lumbered with mechanical woes that could cause just as much
financial grief. How many Mk1s have had thousands thrown at them over the years
to keep them running? More power to those that have the commitment and the will
to keep the earlier models of this car up and running.

Nothing wrong with a dry garage either, ventilation is the key or if you
want to really go for it then get a dehumidifier.

I cannot really agree with the “unfairness” of dragging of the Mk3 /3.5 into
this, I think it is entirely fair that awareness is raised and Mk3/3.5 owners
can perhaps take time to inspect and if required take the very same precautions
you have taken. As far as Mazda’s reputation is concerned, yes it should be
taken to task over this matter, we as Mk3/3.5 owners are not immune to any of
the matters raised unless you have conclusive hard evidence that Mazda are
aware of the issues on some Mk2/2.5s and have fully addressed them in the new
model, I certainly can’t find anything to demonstrate that they have and yes,
this does concern me as both an owner and an engineer. I too was there and saw
the Lancia Betas crumble and when you do a little bit of digging I think AT’s
remarks are a relatively fair comparison when you see what has happened with a
disproportionate number of Mk2/2.5s.

As you say Rich, this has been a good thread with very important issues raised,
not just for the models currently affected but as a heads up for mk3/3.5 owners.

As for an insurance approved body shop, sorry Rich, that is simply a lowest
bid affair and these shops take advice from OEM the same as many other non-approved
shops. I have had personal experience of seeing my insurance company getting taken
to the cleaners by such an outfit when a £500 repair was all that was needed
and yes, they were taken to task over it and found to have replaced completely unnecessarily
a number of very expensive components so would not trust them as far as I could
spit.

Sorry if this appear a long ramble but I do bellieve in the light of the issues on Daddy, we Mk3 and Mk3.5 owners have every reason to be vigilant. 

Cheers,

S

 

 

Good pics worth getting some Dinitrol inside when the rails are fixed.

Which pic do you mean with the holes, this one?

It may be the resin bond between the sandwich AT tells us about see his post with blue car pic nearer the beginning of the thread. That rail looks spot welded to me maybe the glue is also between the plates. 

<< The issue is because of the crumple zones introduced with the Mk2.5; instead of the solid box sections (one layer of metal), Mazda used a telescoping system, of sheets of steel, that I think were bonded or glued together; in an impact, the chassis legs collapse in, instead of bending. The corrosion, from what I understand, starts at the interface between these sheets. The glue must be failing, allowing moisture to get in.>>

All true enough SteveTi, though it is clear to me that we have a skim-reader who prefers to cherry pick his points. Had he read the thread properly he would have been able to answer a few of the hypotheticals he has posted. I think it’s best just to let him get on with it and keep the thread on track. I won’t be responding to him again. Waste of time in my view.

Now, back on the topic. Confused

Mk2/Mk2.5 chassis rot?

Found out something today which surprised me. I’ll post tomorrow when I have time.

Cheers!

 

withdrawn

ah that might be it that glue then. the thing is… when i will attempt to fix it, i should also use glue then???  where on earth i can get that and  do job right. i start to consider to leave this job for a proper garage then. 

itactually crumbles and falls apart around bottom drain holes. what you can see on this picture is layering of that glue and outer shell. what i have done is smoothing out those bumps of uneven surface so shiny stuff is outer shell and grey bit in the middle is that glue. just like you cut out the top of apple for instance. very noticeable near strut mount…

 

 

Hi, well that’s a problem. Difficult to weld to I would think and I wouldn’t try glue. I would ask Mazda and check on the official way of fixing it. It may be that the section cannot be repaired and must be replaced back to the part made of solid construction using repair rails but I’d ask and take it from there.

Very interesting all this. I have just bought a Mk2 and I plan to remove the undertray and wheels to have a look. I have the sill problem which the OP is going to have a look at for me since I phoned them a short while ago.

To keep some perspective though, how many of all of these models on the road are likely to be so corroded? Accepting that there may sub-standard materials used, it could also be that for a given period of time there may have been a either a process change in manufacturing or a materials change and either of these could have happened at one plant or another or all manufacturing sites. It could have affected only a limited number of cars or all.

I work as an engineer that supports a manufacturing site and I see problems arise regularly that are often traced back to a process change or raw material deviation from spec.

As a non expert in auto manufacturing some of these corrosion sites seem to be following stress sites or fractures. I might have expected the bottom of box section to trap water and rot, but the side of a box seems odd. This is what suggests to me that it may be a forming problem (process) or a material (stress sites) issue. Speaking as lay person in this field of course.

Naturally if Mazda did know that either of these conditions existed they’d never publicly admit it.

Maybe a poll is needed to identify percentages of affected cars against age to give a balanced picture of what’s happened to a larger sample of cars.

I’m hoping to maybe have my car checked for this on the next North Thames tech day. I’ll drop Eric a note to see what he thinks.

Having already spent £500 with Garath for the sills I fear the worst…  Sad

On the other hand, at the North Thames dinner on Wednesday evening no-one seemed to have seen any of this rust issue in real life so it is Very hard to tell how wide spread this actually is. Maybe there were some bad production batches for whatever reason? Anyway, until mine has been checked I have a heavy feeling in my stomach…

I’m popping in to Autolink tomorrow so I’ll see what I’ll see I guess! I’ll post back with results.

Good luck with yours, fingers crossed for both of us!

hi, there may be lots of causes for this. it also may be happening due to japan  standards in place. if you think that imported cars are generally fine than it may give senae. as japan do not use salt for gritting rust treatment is weaker as ones used on ruropean cars… therefore rust is about to happen years sooner.

and think simple… chassis pass through zinc bath in production. it take some time to cure and therefore runs down vertical walls on chassis so bamp environment like uk can bite to it well faster… i may be just talking nonsense but there are virtually hundreds of factors affecting the rate of rust advances and is still individual to each car although some may be generic for a lot…

sorry if i derailed topic Angel

 So, if this is corrosion between the metal sheets making up the front legs then am i right in thinking that injecting wax into the rails will be of little or no benefit as it will have no effect on the internal corrosion and that the only long term fix is replacing the legs to restore integrity. If that is the case, then all mk 2.5 s wil suffer this fate in the not to distant future. This seems to mean thatbeing sensible I shall part ex mine whilst it is still ok as the liikely bill on top of the rear arch repairs which also seem inevitable will mean far more expenditure than I am prepared to accept.

This is rather sad as I love the driving experience of my car and will miss it but can not see any point in keeping a car which seems to have no chance of a good lifespan

Scary scary stuff. To make this topic as useful as possible, could we have a write up of how to/what to check and a poll where we can post back our findings eg age, model, general condition of car and condition of our chassis rails so we can see how wide spread this issue is?

I am yet another member who has to spend money on sill work, but Im really wondering what the point is if my car is going to be a scrapper in the very near future Sad

Well after getting a little worried about what I might find I’ve just cleaned up my engine bay and wiped as much muck off the front chassis rails as I could. To be honest I usually keep the engine bay pretty clean so there wasn’t great deal of dirt in there anyway.

So pics below of what I found.

A super duper clean chassis rail, well on the offside anyway. The nearside looks to be as good just can’t get at that just yet to check, need to move stuff like air box etc. Also checked under the wheel arch and all looks good. Just needs a blast with the Karcher and I’ll get some Dinitrol on there for winter.

The rest of the bay looks ok too. Not bad for a 1998 Mk2.

Must stress though that this car was imported in 2008 and has only spent just over 2 1/2 years on the UK’s roads. According to the last owner it spent 2 years stored away when it came into the country.

Mick

 

 

 

Wow, that’s an impressively clean engine bay! Can I ask what your method of cleaning was? Did you remove much to get at everything? It looks like you’ve used a proprietary engine cleaner followed by dressing, was there a pressure washer involved?

I had Autolink have a look at my new purchase today and it got a clean bill of health apart from the sills, which I was aware of when we bought it. I feel much happier now and would like to tidy my engine up to half of the standard of yours! Thumbs up

 Ive just taken a look at my rails on my 54 plate and from above seem to be ok. However managed to take a pic of underside using camera phone and inspection lamp and seems to be surface rust surrounding the hole just forward of anti roll bar mount. Doesnt look too bad yet but obviously something starting i would never have looked at if not alerted to by this thread so thankyou for that. Will soon take undertray off to have a proper look. The most worrying part to me is that I dont see how I can stop this rust getting any worse if it is between these layers. I will spray inside box section with waxoyl etc but this wont get between layers.