A ridiculous MX-5 based notion...

[MrBig]

So this might turn out to be a very short thread.

I've been half looking for a silly weekend car for a couple of years and not really made any progress with it. I'm balls deep into a very long and expensive VW Beetle restoration which is simultaneously both highly sentimental and the bane of my life.

Anyway, years ago I became aware of a company called Paco Motorsports who, for reasons I don't fully understand, decided to make a lift kit for the ubiquitous MX5.

I was very keen on this idea, and have been keeping an eye out for a suitable car for some time now to no avail. About a week before I was due to go on holiday one came up on Marketplace less than half a mile from my house! Obviously I went for a look, spent a long time poking around it and took some advice from several sources.

A few days later I picked it up, parked it on the drive and went on holiday.

Once we were back home, I gave it a quick check over and all seemed good. It's currently at the garage for it's MOT and I'm now wondering if I have made a massive mistake.

Having run it up to temperature a few times all seemed good and then last night it started bubbling coolant out of a small hole in the lid of the expansion tank 😭

It's an aftermarket tank, and the cap seems to intentionally have a hole in it and no obvious pressure relief valve, but the rad cap does. I need to do some reading on how the system works, maybe the header/expansion tank is not normally pressurised like the systems I'm used to?!? 

So right now, I am waiting to hear back how bad it is, panicking that it needs a new subframe and a head gasket and that it will be listed back on marketplace by the end of today.

More to follow... good or bad.

[Matty]

@gm. Even you've not had one of these have you?

[Bear]

Expansion tanks are not pressurised, but they have straw from the radiator cap to balance the pressurised water and keep it from getting air in when it cools - the radiator cap is the pressure valve, it opens, it sends water down the pipe, as it cools the pressure and spring in the rad cap should be matched so it can also draw water back in. A bad seal and the wrong pressure rating can cut off the expansion tank and cause air to be pulled into the radiator - and the small hole in the expansion tank cap is just a breather so the tank doesn't collapse under vacuum or prevent water being returned to the cooling system.

As such, the first and cheapest thing to do would be to replace the radiator cap, 1.1 or 0.9 bar are common I think for MX-5s - pretty sure the RX-7 had problems with 1.1 and was switched to 0.9 bar recommended but I might be remembering the other way around, and it's only relevant in terms of 'these are Mazda radiator caps you might find'.

[Bear]

Check the coolant level in the radiator when stone cold (important!) - and type, in case someone's done what happened to 'my' RX-7 and put the wrong kind in when servicing it/topping it up, as the first things to clog are things like inlet manifold pipes, small galleries for bypassing, and degassing routes/self-bleeding designs, with obvious results.

Also that looks awesome and I'm kinda jealous.

[gm]

4 hours ago, Matty said:

@gm. Even you've not had one of these have you?

this is true although i’d love a go on this one !  looks like a whole heap of fun  

[gm]

rad cap is hopefully a cheap and easy fix, i had similar problems with my mx5 so swapped the rad cap with the one on the exo, both cars decided they were happy (at least until i crashed the exo and wrecked that radiator !) 

[MrBig]

Thanks chaps. Will get a new rad cap sourced ASAP.

@gm if you ever find yourself in Midlands, give me a shout, more than happy for you to have a go once it's all legal.

MOT failed (not a surprise) on a few things:

 

Do not drive until repaired (dangerous defects):

• Front Anti-roll bar missing (5.3.3 (a) (ii))
• Rear Anti-roll bar missing (5.3.3 (a) (ii))
• Anti-roll bar linkage missing All (5.3.3 (a) (ii))

Repair immediately (major defects):

• Front Brakes imbalanced across an axle (1.2.1 (b) (i))
• Nearside Rear Inner Integral body structure corroded to the extent that the rigidity of the assembly is significantly reduced Wheel arch front section (6.1.1 (c) (i))
• Nearside Headlamp aim too low (4.1.2 (a))
• Offside Headlamp aim too low (4.1.2 (a))
• Nearside Rear Exhaust has a major leak of exhaust gases (6.1.2 (a))
• Exhaust Lambda reading after 2nd fast idle outside specified limits Possibly due to exhaust leak (8.2.1.2 (c))

Monitor and repair if necessary (advisories):

• Offside Front Brake pad(s) wearing thin (1.1.13 (a) (ii))
• Offside Front Lower Wing corroded
• Central Front Coolant leak Radiator

Hoping the previous owner still has the anti roll bars and I can refit them and attempt to track down some longer drop links to allow it to be connected.

Fingers crossed replacing the front pads sorts the brake imbalance - how do you test for a sticking caliper when you aren't allowed to drive the car?!?

More hoping sorting the exhaust leak gets it through emissions! I need to figure out what kit I need to read fault codes. Assuming it's not OBD2?

One of these panels on order: Inner arch/Sill end plate -Mx5 Mk2/2.5 Genuine Mazda - The MX5 Restorer

All of this done in two weeks time, with no leave remaining from work and the kids at home for the holidays? Who knows, but we'll give it a go!!

More pics will come this week, just not had the time yet!

 

[Three Speed]

Here’s a pop-up headlamp one that is regularly thrashed around Exmoor. It has quite a bit of additional bracing inside.

[gm]

@MrBig any use to you ? 

https://www.facebook.com/share/16kAukqHE9/?mibextid=wwXIfr

[MrBig]

Oh man. Those are in Ely which is about 90 mins away from me. 

Guess where I drove through today on the way back from a customer 🫣 

Thanks for the heads up though. I have just picked up the original ones from the previous owner of my car. 

Just need to get the flap wheel out now!

 

[DodgeRover]

I take it you are thinking of getting into production car trials then? Anti roll bar will have been removed to improve axle articulation - as far as I was aware if it is completely removed (not just the linkages) then it isn't a fail?

I'm struggling to think which MOT tester on here will have had experience with testing Troll trials cars and similar @scaryoldcortina or @twosmoke300 maybe?

[Snipes]

I didn't know arb removal was a fail?

[EyesWeldedShut]

1 hour ago, Snipes said:

I didn't know arb removal was a fail?

We had this a few years back on a Land Rover forum <<here>>

Suggestion then was that it was introduced in 2010 i.e. modern changes:-)

 

[scaryoldcortina]

Ok... while section 5.3.3 a(2) says a suspension component missing is a dangerous fail and arb is within this catagory, section 13 of the introduction says

 

If a vehicle has been extensively modified or converted, certain defects, such as for components ‘missing where fitted as standard’ should not be applied, for example:

• a car converted for competition rally use must have the rear seats removed, be fitted with a roll cage and full harness seat belts, may not be fitted with components such as brake servo, power steering or airbags
• a car converted to a stretch limousine may no longer be fitted with items such as curtain airbags or a functional electronic stability control system

This exemption does not apply to vehicles with minor modifications. Therefore, a car fitted with rally style seats, body kit and a sports steering wheel would not be exempt from the requirement to have a driver’s airbag if one was fitted as standard equipment.

 

So, if your car is obviously modified for track use and the lack of arb is because of this you could argue extensive modification and pass.

 

This doesn't work for people who removed a snapped arb from a disco 3 and played dumb about it.