Timing belt question

XS11E wrote:
> "news" > wrote:
>
>> My 1995 Mazda 626 has 152,000 miles and the belt has never been
>> replaced. YMMV.
>
> The previous owner of my 1992 said the belt broke around 120,000 miles.
>
> The best guess I've gathered from people here and elsewhere is that the
> belt is *PROBABLY* good for 100,000 miles and that Mazda's
> recommendation is *PROBABLY* conservative. As always, YMMV.


One would think that Mazda would want the probability of failure
before 60k miles to be almost zero. It would have to be VERY
conservative for that to be true. I did replace it at 60k but
I'm not inclined to at 130k. Any experiences with Miatas?

Natman wrote:

>
> If the manufacturer recommends 100K, the owner is outraged that the
> %^$%$^%$ timing belt broke, even though he followed the maintenance
> schedule.
>
> Still, you should still change the belt at *around* 60K.

Why?
--

zenmartini wrote:
>
> I know the timing belt is supposed to be replaced at 60k. My 2000 is
> at 75k but the belt is in good condition... no nicks etc. Money is
> tight at the moment... how much longer can I go before this has to be
> replaced... I know that I'll be stuck wherever I am but there is no
> damage that can occur right?

Ideally if money's no object you want to go with the suggested
maintenance schedule, but broke as I am, I'll probably wait until
100,000 miles. Why? Because in California, the exact same timing belt
that Mazda says you should replace at 60,000 miles in the other 49
states, they say is good until 105,000 miles there. This has something
to do with California's elaborate car regulations, but the fact remains
that Mazda wouldn't ship Miatas with a timing belt that they'd expect to
fail prior to the manual's scheduled replacement date.

I bought a used '93 and the previous owner had never changed the timing
belt. In 2004, at over 100K miles, the radiator sprung a leak. I
figured since I was paying for the labor to take the radiator out
anyway, I'd finally replace the timing belt and the water pump too. The
old belt looked surprisingly good, even after 11-12 years. I was
actually more worried about the water pump, and when they had it exposed
and the belt off, you could wiggle the shaft laterally so you could tell
that water pump would probably have failed pretty soon.

So that's the other suggestion; when you finally do get the timing belt
done, while you're in there, replace the water pump too; it's only about
a $75 part, but if it fails it'd cost an additional $150-$200 in labor
to take off the stuff you need to to get at it, not to mention you might
ruin the cylinder head if it overheats.

Yours WDK -

"miker" > wrote:

>> >The best guess I've gathered from people here and elsewhere is
>> >that the belt is *PROBABLY* good for 100,000 miles and that
>> >Mazda's recommendation is *PROBABLY* conservative. As always,
>> >YMMV.
>
> When I first started reading this group I remember this subject
> coming up. It was said that the water pumps often start to fail
> near 100k and all the same stuff has to come off, so do the belt
> and the water pump between 80k and 100k.
>
> (No experience myself with this, just remembered it as sounding
> sensible.)

Based on my own VERY limited experience (one Miata) and reading
collected input of this group and Miata.net, I will personally change
timing belt, V belts, Crank seal, Cam seals, water pump and idlers
every 100,000 miles. As always, YMMV

cramer > wrote:

> One would think that Mazda would want the probability of failure
> before 60k miles to be almost zero. It would have to be VERY
> conservative for that to be true. I did replace it at 60k but
> I'm not inclined to at 130k. Any experiences with Miatas?

Someone said that to conform to California rules, Mazda changed the
recommendation in California to 100,000 miles, does anyone know if
that's true or not?

I suspect the California belt is the same part number, isn't it?

XS11E > wrote:

> cramer > wrote:
>
>> One would think that Mazda would want the probability of failure
>> before 60k miles to be almost zero. It would have to be VERY
>> conservative for that to be true. I did replace it at 60k but
>> I'm not inclined to at 130k. Any experiences with Miatas?
>
> Someone said that to conform to California rules, Mazda changed the
> recommendation in California to 100,000 miles, does anyone know if
> that's true or not?
>
> I suspect the California belt is the same part number, isn't it?

Sorry, I posted before reading W. Kiernan's excellent post on the
topic.

Well what can I say? You can go to "miata.net " and you can find
about "ALL" the information you need in the "Garage" section. How to,
when to, where to [ :-) "what it is" ] It will tell and show you how to
change the tinning belt. If you are the mechanic that it sounds like
(and I thought you knew what you were talking about with the timming
belt :-) ) , you can change the belt. Ya just need to read the
instructions. Go for it !!!!!

Bruce Bing 03 LS

"W. Kiernan" > wrote:

>zenmartini wrote:
> >
> > I know the timing belt is supposed to be replaced at 60k. My 2000 is
> > at 75k but the belt is in good condition... no nicks etc. Money is
> > tight at the moment... how much longer can I go before this has to be
> > replaced... I know that I'll be stuck wherever I am but there is no
> > damage that can occur right?
>
>Ideally if money's no object you want to go with the suggested
>maintenance schedule, but broke as I am, I'll probably wait until
>100,000 miles. Why? Because in California, the exact same timing belt
>that Mazda says you should replace at 60,000 miles in the other 49
>states, they say is good until 105,000 miles there. This has something
>to do with California's elaborate car regulations, but the fact remains
>that Mazda wouldn't ship Miatas with a timing belt that they'd expect to
>fail prior to the manual's scheduled replacement date.

Actually, I understand from Miata magazine that while California requires
the belt must last 100 kmi, Mazda still requires the belt to be *inspected*
after 60 kmi. They felt that if they go through that trouble, a mechanic
might as well replace it.

I do not remember seeing any posts here reporting a belt breaking before
100 kmi though. All the ones I remember were over 100 kmi.

Of course, not replacing at 60 kmi has the disadvantage that you cannot
blame Mazda for the chain collision you caused having your belt go out
at 70 kmi in the middle of a busy freeway in front of that SUV that
was not on the cell phone at the time. The legal responsibility
will be all yours.

Leon

>I bought a used '93 and the previous owner had never changed the timing
>belt. In 2004, at over 100K miles, the radiator sprung a leak. I
>figured since I was paying for the labor to take the radiator out
>anyway, I'd finally replace the timing belt and the water pump too. The
>old belt looked surprisingly good, even after 11-12 years. I was
>actually more worried about the water pump, and when they had it exposed
>and the belt off, you could wiggle the shaft laterally so you could tell
>that water pump would probably have failed pretty soon.
>
>So that's the other suggestion; when you finally do get the timing belt
>done, while you're in there, replace the water pump too; it's only about
>a $75 part, but if it fails it'd cost an additional $150-$200 in labor
>to take off the stuff you need to to get at it, not to mention you might
>ruin the cylinder head if it overheats.
>
>Yours WDK -
--
Leon van Dommelen Bess, the Miata Bozo, the Miata
http://www.dommelen.net/miata
The only thing better than a white Miata is two white Miatas

On Fri, 04 May 2007 21:44:59 -0400, cramer > wrote:

>Natman wrote:
>
>>
>> If the manufacturer recommends 100K, the owner is outraged that the
>> %^$%$^%$ timing belt broke, even though he followed the maintenance
>> schedule.
>>
>> Still, you should still change the belt at *around* 60K.
>
>Why?

Because I'm not fond of the idea of waiting for the belt to break,
leaving me stranded God knows where or when. And yes, the Miata is a
non interference engine, but that doesn't mean that a flailing belt
can't cause other damage.

Personally I changed my belt at 75K. (I boutght the car with 68K and
the original belt) It looked fine and would probably have gone
another 25K, but now I don't have to worry about it for another 75K.

Also on NBs the valve clearances should be checked at 60K and if any
need changing you might as well do the belt then since a lot of the
work overlaps.

>
> Of course, not replacing at 60 kmi has the disadvantage that you cannot
> blame Mazda for the chain collision you caused having your belt go out
> at 70 kmi in the middle of a busy freeway in front of that SUV that
> was not on the cell phone at the time. The legal responsibility
> will be all yours.
>
> Leon

Dunno how things work over there in "The land of the free", but over here if
you run into the back of another vehicle, you are almost certainly in the
wrong. (possible exceptions are if the driver in front is drunk, driving
unlicensed, reversing, or deliboratly attempting to cause an accident).
Some idiot talking on a mobile driving into the back of a your car when if
broke down would be in the wrong.

Loosing power while accellerating into a small gap in traffic, or crossing
lanes could see you in the wrong. Also breaking down in the middle of
nowhere, or the middle of somewhere bad would not be fun.