Miata questions

I am looking at a Miata and have some Miata questions that I am sure the Miata experts on this forum can help me with: 1. I am looking at a 1996 Miata with 130K miles, is that considered high for a '96 Miata?
2. What's the timing belt change interval? Is the engine interference engine or not?
3. If I can get a hold of the VIN number, who should I call from Mazda USA to check if it has Torsen or not?
4. As far emission craps, should I worry about them (this being a 1996 - OBDII)? I am not planning any radical modifications, mainly for autocross so engine wise it'll be maintenance and some bolt-ons, nothing fancy.

Thanks all.

ea_sport wrote: I am looking at a Miata and have some Miata questions that I am sure the Miata experts on this forum can help me with: 1. I am looking at a 1996 Miata with 130K miles, is that considered high for a '96 Miata? 2. What's the timing belt change interval? Is the engine interference engine or not? 3. If I can get a hold of the VIN number, who should I call from Mazda USA to check if it has Torsen or not? 4. As far emission craps, should I worry about them (this being a 1996 - OBDII)? I am not planning any radical modifications, mainly for autocross so engine wise it'll be maintenance and some bolt-ons, nothing fancy. Thanks all.

Do a search on the website for a buyers guide. I'd do it for you, but am working from a bad internet connection. Just search "Miata Buyers Guide".

1: I would not be afraid of that at all, assuming they've taken care of it. These cars will commonly go 300,000+. Do a search on miata.net for it and you'll find the info.
2: Assume you have to do it, but non-interference engine.
3: No idea
4: A 97 just won E-stock at nationals.

Here's the link to the buyers guide: http://grassrootsmotorsports.com/articles/mazda-miata/

1. They do last well if looked after, so I wouldn't be afraid of the mileage. Buy on condition, not mileage.
2. Not an interference engine but IIRC the belt change interval is 60k and you should change the waterpump at the same time.
3. +1 no idea
4. I've not had an ODBII one, but I doubt the emissions system is that complicated.

I'd just go over it and check for regular wear and fix that before considering any bolt-ons. They're pretty good stock.

There's a differential spotters guide @ miata.net that may be of utility, as well as buying guides out the wazoo.

What everyone else said - buy on condition. My 90' NA had 125k miles and was nice, but needed a full service and freshening. It's pretty great now - but I bought it under the assumption I'd double the purchase price with OEM parts and "tasteful mods".

Thanks for all the reply guys. I saw the GRM buyer's guide, in fact I still have that edition, I just want to know what others think here from owner's standpoint.

I am looking at buying a 1990 and I know they have the problem with the crank pulley. Do I just reach down in the engine and see if pulley wobbles by moving it by hand or do I need the engine running and watch to see if it wobbles? I am sure I will need to change the shocks but anything else I would need to replace. It has a whopping 83k miles on it.

Correct me please but I think all Miatas (NA and NB at least) that have leather have the Torsen.

All non-base 1.8s have a torsen.

PS, OP, I'm in Springfield, just south of you. If you've got any Miata questions, or want a hand looking at a prospective car, let me know.

No pre-94 Miatas had the torsen.

How hard is it to do the NB shock conversion? Any one done this.

Holy cow! For a bunch of Miata owners/fans you guys have it ALL wrong! For Torsens:

1. Torsen LSD is only available on the 1.8 NA's (94-97) and NB (99-05).

2. The Torsen only came STANDARD on 4 models. The "R" Package 94, the "M Edition" in 94-97, the 97 "STO", and the Mazdaspeed.

3. The Torsen was OPTIONAL on all other 94-05 Miata's as a STAND ALONE option. Leather DOES NOT equal Torsen.

4. The Torsen is NOT available on ANY automatic Miata.

Now, on the pulley/crank snout issue, ALL 1.6's have it. The short nose cars, the long nose replacement cranks, and the fat nose cars. If you have a 1.6, expect to have to do some repair work down there.

Next, the NB shock conversion is stupid easy. Use the NB mounts on the rear shocks. Done. FM's fancy ones are basically NB mounts.

For the OP:

1. No, that's fairly low-to-normal. Buy on condition. I've driven 250K mile Miata's that are nicer than my 160K mile one.

2. 60K, non-interference, change the water pump at the same time. Buy a new crank key, bolt, and expect to change the balancer sooner or later.

3. Call Mazda Customer Service.

4. Leave it alone, it works fine and doesn't eat much power.

Javelin wrote: Now, on the pulley/crank snout issue, ALL 1.6's have it. The short nose cars, the long nose replacement cranks, and the fat nose cars. If you have a 1.6, expect to have to do some repair work down there.

What exactly is needed for the 1.6 crank issue? How hard is it to fix?

Well the stupid woodruff key isn't long/beefy enough. What happens is it either breaks or pounds the keyhole of the crank into submission. You fix it by using some Permatex stuff (they make a specific metal compound for repairing keyways in shafts) to strengthen the crank, replacing the key with a new MAZDA one, and replacing the crank bolt with a new MAZDA one (and using Permatex Threadlocker on it). On the 92/93's you may have to repair or replace the hub that the balancer bolts to as well.

While you're down there doing all that crap you might as well do a timing belt/water pump and replace the balancer as well. New MAZDA ones are under $100. The rubber in them degrades and they get out of balance, which is what leads to a lot of the issues, at least that's what happened to me.

Uh, the Torsen is on all of the 94+ non-base/automatic Miatas. I guess the Torsens on the Miatas I've owned have just magically appeared.

SpeedTheory wrote: PS, OP, I'm in Springfield, just south of you. If you've got any Miata questions, or want a hand looking at a prospective car, let me know.

Thanks for the offer, the thing is this one is out of state. I'll have to take you up on your offer if I find anything closer though.

In reply to Javelin:

Do you need to pull the engine do this? How many hours does it take to do this job? If the key isn't broken yet, do I need to do anything?

SpeedTheory wrote: Uh, the Torsen is on all of the 94+ non-base/automatic Miatas. I guess the Torsens on the Miatas I've owned have just magically appeared.

Uh, again, wrong. It is part of an option package or available stand-alone. That does NOT mean it's on all of them!

Miata.net FAQ

Year-to-year changes

GRM Buyer's Guide

They all agree that the Torsen was optional, and not just the base models.

The poster formally known as 96DXCivic wrote: In reply to Javelin: Do you need to pull the engine do this? How many hours does it take to do this job? If the key isn't broken yet, do I need to do anything?

No, about 2 hours to fix the crank plus the 4-6 to do the timing belt, water pump, etc if you are taking your time, and yes, you should change the key and bolt every time the pulley is removed.

PS - The Mazda Customer Support number is 1-800-222-5500 for the VIN decode and option (including LSD) information.

Javelin wrote:

The poster formally known as 96DXCivic wrote: In reply to Javelin: Do you need to pull the engine do this? How many hours does it take to do this job? If the key isn't broken yet, do I need to do anything?

No, about 2 hours to fix the crank plus the 4-6 to do the timing belt, water pump, etc if you are taking your time, and yes, you should change the key and bolt every time the pulley is removed.

I meant should I go and do and take it all apart and replace the key even if I didn't need to replace the timing belt and etc.

Not unless the pulley wobbles, the engine/drivetrain has vibrations, or the balancer looks degraded. Most used Miata's need a timing belt though, as being non-interference people never change them.

I will talk to the guy but considering how well the car has been maintained I would be surprised if it hadn't.

A few corrections.

The 1990-93 viscous LSD was a standalone option, the 1994-05 Torsen was always tied to various packages. It wasn't a standalone option. If I remember correctly, if the car has a power radio antenna it has a Torsen. The big exception is automatics, no automatics came with the Torsen. A call to Mazda customer relations (800-222-5500) can clarify for a particular car, but any leather car with a stick will have a Torsen. I know for a fact that the GRM buyer's guide doesn't say the Torsen comes as a standalone, and if you want a more fully researched option package list check Mazda Miata: Find It, Fix It, Trick It.

The 1991-93 1.6 crank nose is the same as the 1994-05 cars. No Miata will be happy if you don't torque the crank bolt properly. The appropriate repair for a damaged crank depends on how bad the damage is. Check out "Loctite repair" for the full recipe put together by some Australian engineers who work at Loctite. On an 83k 1990, I'd find out if the belt has been changed - and if not, use that as an opportunity to inspect the nose yourself. There are far more healthy Miata crank noses out there than bad ones. The failure rate on the similar GTX crank seems to be dramatically higher for some reason. Personally, I'd only replace the hardware if I saw signs of wear, and usually the wear is due to a loose crank bolt. The one thing you do need to do is torque the bolt correctly and use blue Loctite on it.

This one in particular I have to address directly.

Javelin said: Next, the NB shock conversion is stupid easy. Use the NB mounts on the rear shocks. Done. FM's fancy ones are basically NB mounts.

This is not true. If you simply slap NB mounts in place of NA ones and bodge around with some bushings to make it fit on the NA shocks, you'll find the car will drop about 1/2". If you only do this on the back, the back of the car will drop. The FM mounts are a custom-made piece with different geometry that will keep the same ride height as the NA mounts but add considerably more compression travel. Very different than a factory NB part.

The smart way to do an NB change is to swap out everything together: springs, shocks and upper mounts and associated bushings. FM does sell their shock packages like this, and it's a straight bolt-in that will still ride at the design ride height of the springs.

At 130k, a Miata is either due for a timing belt change or it had one in the past 10k. There are are a lot of very conscientious Miata owners out there who do follow Mazda's recommended maintenance schedule, so don't assume it hasn't been done. But the good thing is that, if the change was done, it was probably done by the current seller so you can find out. I consider the lifespan of a Miata belt to be right around 80k - some last longer, but I've pulled a couple of broken ones out of cars with this mileage.

Javelin wrote: Holy cow! For a bunch of Miata owners/fans you guys have it ALL wrong! For Torsens: 3. The Torsen was OPTIONAL on all other 94-05 Miata's as a STAND ALONE option. Leather DOES NOT equal Torsen.

Wow you're all fired up huh?

I dunno, pretty sure the "Leather Package" also called "Package C" (most commonly tan leather interior and tan roof) included LSD on manual cars at least. I don't know either way if the Torsen was avail. on any car as an option.