Timing belt question

Technically yes. But what a jury aware of real life on the highways will think is another matter.

I am sure a jury would look unfavorable on the fact that proper maintenance was *not* performed, leading to a car coming to a full stop in the middle of the freeway without any brake lights to show for it.

Which is why I noted he was *not* on the cell phone, according to the available evidence.

Leon

The biggest risk is that it fails halfway through an overtaking manoeuvre. However, and for reasons I don't understand, the Miata/MX-5 belts normally fail when the engine is first fired up.

The rubber is harder when the belt is cold?

Leon

, replace the water pump too; it's only about

$75 might be Mazda pricing, not sure but when I replaced my waterpump on the NA a couple years ago it was like $30 @ Autozone (I know some people will groan abouthe Zone). I figure at the first timing belt change, the waterpump usually doesn't get changed but at the second it seem silly not to.

Chris

I think it's very likely that's exactly the reason. Another part of it may be that initial start up puts more torque on it than gradual acceleration does.

Chris

The torsional forces on the belt are highest at lower speeds, engine turning at start speed-ca 200rpm.

Also oil is cold & more viscious.

I changed my timing belt somewhere in the 75-80k mile range. Unfortunately I didn't know to do the water pump too. The water pump went about 30k miles later.. so I got a new water pump and a new timing belt. If you're doing one, always do the other. I have about 60k miles on the "new" water pump and timing belt, and plan to replace them when they have about 100k miles on them.

-Scott

Maybe just me, but I hate when my oil gets viscious.

Inertia. The two I had fail (not in MX5) occurred at startup and in one case when warm. I guess when started there is a sudden change in lateral tension on the teeth from nothing to something high before it calms down and everything gets moving. I guess the only other time the rate of change is approached is when you put your foot down hard.

Did they fail when you were cranking the engine or when it started?

Leon

Thank you all; I replaced it at 60k but now that it's 136k, I think it's not worth replacing for the rest of the car's life (unless the water pump goes)

Not for the rest of the car's life? Heck, that baby's just barely broken in at this point. We've got a couple members in our local club that have over 250,000 miles on their Miatas.

Unless you're planning on blowing up the engine or destroying the car in an accident, I'd re-think that position.

Iva & Belle.) '90B Classic Red.) #3 winkin' Miata

I agree but maybe when he says, "the rest of the car's life" he means "as long as I'll own the car?"

I'm wondering if maybe he's got an idea there? I have a towing service card, a cell phone and the Miata is a non-interference engine, maybe it's less expensive to just let the belt break and then get towed to a shop? I don't think I'd do that but.....

And if it happens to break on Saturday night in the crack-house district?

People with Miatas don't hang around the crack-house district on Saturday nights. ;)

Can't. She Who Must Be Obeyed doesn't let me go to the crack-house district.

I've heard that Lesbian or Transgendered drivers will often drive near crack-house districts, but not for proximity to crack. Saturday nights show a 73rd percentile comparative to mean of other days of the week. (Not true for Gay or Bisexual drivers tho.)

C'mon funding, c'mon funding...

miker

Cranking. Never seen one snapped but seen where teeth start to part company with belt.