how good are the MX5 engines?

[speed freak]

Hey guys, as some of you may already know Im looking at getting an MX5 in the near future. It will be a daily driver with a few local street sprint track days throughout the year. Iv really come to like the MX5 more and more recently but I have never had anything to do with them so my main question is what are the engines like? I service and maintain any of my cars that I own and change oil and filter before and after when I do track days but is there anything in particular weak about these engines and is tracking it going to hurt it or anything need changing/upgrading before tracking it? (obviously the harder you drive a car the quicker things will wear out thats ok i realise that just interested in the overall strength/durability of the engines)

As it will be my daily I just want reassurance that after a track day it will get me to work after still haha. Im sure Im just being really paranoid as Im used to new cars and tracking those so you can drive them as hard as you want and they dont mind its just a little nerve racking going back to a older (but more fun) car.

Im looking at getting either a NA or NB

I read somewhere that the engines used in the MX5 came from the old astina? These are not sporty cars at all (except the sp20) so are these great handling cars let down by the engine or are they not that bad? I figured they must be pretty good as Iv seen numerous amounts of performance upgrades available.

Anyway Ill leave you to it, any help will be greatky appreciated

cheers

[hks_kansei]

The engines life depends on hwo it's maintained.

I know people who've had to replace engines after 150,000km

My partner's NA6 rolled past 400,000km early last year on the original engine (not rebuilt, as is from the factory)

[zero00]

My NB8A [early 2000] had 110,000km when I bought it 3 years ago. While the suspension has been changed, swaybars added along with wider alloys and street legal track tyres the engine remains standard

It now has 151,000km and has done 15 track days, oil is changed after every second meeting and I use top quality oil designed for high revving, maintained by MX5 Plus in Brisbane

It doesn't use a drop at all and on a track day would be hitting 6500-7000rpm 2-3 times each lap without a problem!! So, for the best part of 15km it's having it's butt screwed off like never before and coming back for more!!

On Monday I did 65 laps, equates to around 150km without missing a beat and then after, driving home, ran sweet as ever!!

Bottom line is how you have it maintained and of course how it was maintained before you made the purchase! I'm NOT a mechanically minded person so I have to rely on having it maintained by the best available - I do however, know how to check the tyres!!

Good luck!!

[StuwieP]

Some of the early 1.6 models suffer from 'crank nose failure' (not sure exactly what the problem is called) - google 'mx5 short nose crank' for lots of info. For reference, pretty sure mine is a short nose, I'm about to hit 250,000km and my engine hasn't fallen apart yet. Love my 1.6. Doesn't make much power so you're not asking much of the engine.

Some new cars are more problematic than ours. Cheaper to fix if something does go bang too. Like everyone else has said, maintenance is key.

Best of luck, welcome (pre-emptively) to the community

Cheers
Stu

[manga_blue]

They're basically tough little engines, not high power but dependable. They're also relatively simple and easy to fix. They'll easily stand up to 400,000kms and dozens of track days provided they get good fresh oil regularly and the usual routine services: cooling, belts, hoses, etc. You can pull down engines that have done 200,00kms on synthetic oil and find no piston wear and see all the original factory honing marks in the bores.

There are one or two weaknesses that do get exposed on track days, even on stockish engines. Coolant enters at the front and exits at the front, leaving cylinders 3 and 4 under-cooled on severe days. It's a hangover from a cheap conversion from FWD. A coolant re-route kit allows coolant to pass right through the block and head, exiting at the rear of the head and virtually eliminates head gasket failure. It's not essential but you get peace of mind if you're racing when it's 40 in the shade.

A lot of track day beginners burst cooling hoses too, usually one of the many hidden little ones around the heater, back of the head, throttle body or manifolds. These often get missed in normal services. Replace all of them before your first track day, then I won't get any more burnt knuckles helping people fix their cars to get home.

Crank nose failure is all too common. The timing belt pulley works loose after a poorly executed timing belt change. It's evidenced by a wobble in the crankshaft pulley. Don't buy an MX5 with any pulley wobble unless you get a discount for the cost of a new engine.

[manga_blue]

Some of the early 1.6 models suffer from 'crank nose failure'

Actually all NA and NB models can get it. All it takes is a bad mechanic doing the belt change. Mazda improved the crank nose design over time but never completely eliminated the risk.

[NitroDann]

Crank nose failure is one of those things that can happen to anything, however is common early early 1.6L mx5's.

Dann

[KevGoat]

I have a 1990 NA6 with 220,000+ k's .... as far as the previous owner and any history shows, nothing to do with "SNC" issues has ever been touched! Still a damn strong feeling engine. No issues burning oil. Rev's out to redline beautifully Tuned and idles perfectly. I change all oils and serviceable items very frequently even if just sitting around unused and especially as soon as any tappet noise appears and I use good quality oils.

Tend to think the SNC issue has been blown out of proportion over the years ...

I'm mechanically naive, but I love learning and working on these simple cars.

[StuwieP]

Crank nose failure is one of those things that can happen to anything, however is common early early 1.6L mx5's.

Dann

Isn't the problem that the short nose is more prone to wearing/being damaged during maintenance, rather than being solely confined to early NA6s? But yes, I wasn't suggesting that the OP should discard any 1.6 short nose (hell, I didn't) because this 'could' happen, or that all of the NA6s would break, just to be aware of the issue, and to know what to look for.

[NitroDann]

Yeh I believe both poor fitting and leaking waterpumps are the causes, the first engine I had developed a wobble, which was very easily fixed, due to a previous leaky water pump.

Dann

[speed freak]

thanks guys for all the great and very helpful comments. theres too many to qoute and reply too so ill just reply in general haha.

These sound like there pretty good little engines, sound very tough and dependable as long as you look after them it will look after you. I realise maintenace is the key to an engines life so Ill definately try to get one with a good service history and before I buy it ill prob get it checked over by someone and possibly a compression test to make sure. I always service and look after my cars with the best quality oil and parts so thats no drama.

I probably should have mentioned I had already seen the short nose crank problem and have read up thoroughly and if Im right it was only the very early ones so after 91 they changed the design or something? As mentioned above its a possibility in either a na or nb but thats one of the main areas Ill be checking when I look at a mx5.

Are parts still easily available for these engines? I realise Im just being paranoid as Iv been a new car snob for a while now lol. Iv only had one 'old' car and the engine was very very problematic and I wouldnt have ever considered tracking it as it would have sh*t itself for sure haha but Im very keen and excited to get into a fun raw drivers car again. Being a little underpowered doesnt really worry me. I find these sort of cars to be alot more fun to drive anyway as you have to actually drive them to go quickly. I used to have a 06 swift which handled like a go cart and it was a hoot to drive because of its short wheelbase and lack of weight.

Thanks again for the un-official welcome to the MX5 club hopefully Ill be an official member soon once I get my very own MX 5

[manga_blue]

Parts are all pretty easy. Mazda dealers are a bit exxy but they carry most stuff. mx5parts.co.uk stocks almost everything you'd need in terms of genuine parts and their shipping is fast. Lots of stuff new or used on fleabay. Performance parts come from a whole range of Oz and US (and occasionally Japanese) sellers.

[93_Clubman]

My old '89 NA6 experienced the SNC issue at less than 100k kms - up to that point it had only ever required routine servicing which had all been done on time by Mazda dealers (bought it with about 3k kms on the odo). Fortunately was fixable & never caused me any issues again, & was sold at about 180k kms.

[speed freak]

My old '89 NA6 experienced the SNC issue at less than 100k kms - up to that point it had only ever required routine servicing which had all been done on time by Mazda dealers (bought it with about 3k kms on the odo). Fortunately was fixable & never caused me any issues again, & was sold at about 180k kms.

ah thats no good. some people seem to be lucky with this problem and others not so much. I had a look at a MX5 not to long ago this morning and it definately had the SNC problem. He started the car and the crank pully had a very noticeable wobble to it. Engine itself made no weird noises and didnt even have a tappet noise but that wobble turned me away. Which is ashame really because its a bloody nice looking car.

Also I checked out that mx5parts website, you could remake a mx5 from all the parts they sell on there lol (it would be quit costly but you know what i mean) its good to know you can still get any part you need for them.

[Soft On Top]

My first MX5 - a 1.8 NA - had 420,000 Km on the clock when i traded it in for my first NB. The original motor with no overhauls. Just brilliant. A young chap bought it and it can still be seen on the road.
No magic : simply serviced every 5000Km -