[Tech] timing belt

[Janice]

I keep hearing that the timing belt needs to be changed around 60k, but my car has 97k on it and the timing belt has never been changed to my knowledge. Some people are telling me to ride it till it breaks cuz it won't hurt anything badly and others are saying change it now, but when I priced changing it one mechanic told me he wouldn't touch it because it has a double overhead cam in it which complicated matters and the dealership tells me it will be $500 to change - ouch! I would like to know if anyone has had them break and how many miles were on it when it happened and how expensive the damage, if any, was... Thanks!

[Duncan]

Originally posted by Janice@Mar 3 2005, 05:05 PM
I keep hearing that the timing belt needs to be changed around 60k, but my car has 97k on it and the timing belt has never been changed to my knowledge.* Some people are telling me to ride it till it breaks cuz it won't hurt anything badly and others are saying change it now, but when I priced changing it one mechanic told me he wouldn't touch it because it has a double overhead cam in it which complicated matters and the dealership tells me it will be $500 to change - ouch!* I would like to know if anyone has had them break and how many miles were on it when it happened and how expensive the damage, if any, was... Thanks!

[snapback]252698[/snapback]

If it breaks, your engine won't be damaged - the Miata engine is what's known as a non-interference design. This means that if the timing goes out of whack for any reason (like, say, a broken timing belt), the valves will not hit the pistons or cause anything else in the engine to break.

So that much is true. But...at nearly 100k, you're basically asking for the timing belt to break exactly when you don't want it to. And that's usually when you're out in the middle of nowhere.

Yes, it will be a little pricey. But you can do much, much better than the 500 bones your dealer wants - find a good shop that specializes in imports and get their quote. I'm betting it'll be closer to $200-300. And really, that's cheap peace of mind.

Let us know what you decide. Oh, and welcome to the forums!

[Janice]

Originally posted by Duncan@Mar 5 2005, 06:38 PM
If it breaks, your engine won't be damaged - the Miata engine is what's known as a non-interference design. This means that if the timing goes out of whack for any reason (like, say, a broken timing belt), the valves will not hit the pistons or cause anything else in the engine to break.

So that much is true. But...at nearly 100k, you're basically asking for the timing belt to break exactly when you don't want it to. And that's usually when you're out in the middle of nowhere.

Yes, it will be a little pricey. But you can do much, much better than the 500 bones your dealer wants - find a good shop that specializes in imports and get their quote. I'm betting it'll be closer to $200-300. And really, that's cheap peace of mind.

Let us know what you decide. Oh, and welcome to the forums!

[snapback]253388[/snapback]

Thank you so very much for your reply! I was really worried that it was going to cause major damage. Unfortunately, I am single and trying to put a 19 and 16 year old through college and money is extremely tight right now and I haven't been able to find anyone as of yet but am looking. Yes, at this mileage, I know I am asking for trouble and it is only through God's grace that it hasn't broken yet. That is why I was asking the general range in which people have had them break. I am trying to sell it now so I can get the money needed to pay for college for the two boys, but love the car and other than that have had no problems with it and would love to one day own another one. They are definitely my favorite...handle great, look great...gas mileage is great...what more could one ask! Thank you ever so much for your help on this! God bless!

[Duncan]

Originally posted by Janice@Mar 5 2005, 11:19 PM
Thank you so very much for your reply!* I was really worried that it was going to cause major damage.* Unfortunately, I am single and trying to put a 19 and 16 year old through college and money is extremely tight right now and I haven't been able to find anyone as of yet but am looking.* Yes, at this mileage, I know I am asking for trouble and it is only through God's grace that it hasn't broken yet.* That is why I was asking the general range in which people have had them break.* I am trying to sell it now so I can get the money needed to pay for college for the two boys, but love the car and other than that have had no problems with it and would love to one day own another one.* They are definitely my favorite...handle great, look great...gas mileage is great...what more could one ask!* Thank you ever so much for your help on this!* God bless!

[snapback]253566[/snapback]

Glad to help! Let us know what happens.

[MiataMan68]

If you don't change it, it may or may not hurt the car. I have changed the timing belt on 4 different miatas and over 5 times on my last one. If you have any knowledge of how to work on engines it takes about 5 hours worth of work and about $150 worth of parts.

[auditech]

Originally posted by MiataMan68@Mar 14 2005, 04:58 PM
If you don't change it, it may or may not hurt the car.* I have changed the timing belt on 4 different miatas and over 5 times on my last one.* If you have any knowledge of how to work on engines it takes about 5 hours worth of work and about $150 worth of parts.

[snapback]256155[/snapback]

I guess I am confused by the two responses. My wife has a '91 Miata with the 1.6 DOHC engine. Is it an interference fit engine or not?? She has 59,000 on the clock right now and I am wondering if I need to hurry up and replace the timing belt and waterpump or can it wait a little bit. Are there special tools needed to replace the belt?? I am an audi tech by trade so I figured that nothing should really throw me for a loop but I thought I would ask those who have done it before. Thanks for your time.

[jalston@iglide.net]

I guess I am confused by the two responses. My wife has a '91 Miata with the 1.6 DOHC engine. Is it an interference fit engine or not?? She has 59,000 on the clock right now and I am wondering if I need to hurry up and replace the timing belt and waterpump or can it wait a little bit. Are there special tools needed to replace the belt?? I am an audi tech by trade so I figured that nothing should really throw me for a loop but I thought I would ask those who have done it before. Thanks for your time.[/b]

This is really a belated reply, but I dont know of any problems other than inconvienence that a broken timing belt on a 1.6 or 1.8 will cause. All the miata engines are non-interference.I will limit that comment to NA models, because I have no experience with NBs or NCs. and it assumes no performance modifications have been made that would reduce the valve/piston clearances. I would wait until 70k+ before worrying about it breaking, and I wouldn't concern myself about the wp until the second time on the timing belt. When you do do the TB however, I would suggest you also replace the camshaft and crankshaft seals as well as the valve cover gasket and CAS o-ring.