Mazda 929 Broken Timing Belt

Anyone experience a broken timing belt on a 1988 929 engine? Son's car
just had this happen and we are wondering what the chances are that things
(pistons valves) 'survived? I am assuming that this is a destructive
engine. Car was only going about 15 MPH when this happened.

We would like to undertake repairing this ourselves.Anyone gone though this?
Any advice appreciated.

Thanks.

In article <47823561$0$11009$4c368faf@roadrunner.com>,
"Bob" <rkindt@hvc.rr.com> wrote:

> Son's car
> just had this happen and we are wondering what the chances are that things
> (pistons valves) 'survived? I am assuming that this is a destructive
> engine.

It depends... Cars with dished top pistons (or even flat top pistons
with divots where the valves would normally impact) can survive a broken
timing belt just fine... I had this with my old FORD ESCORT WAGON
(1991). My timing belt broke in the middle of nowhere at 100 KM/HR. I
didn't even no what it was originally, and tried to start the engine,
etc. at first.

Anyway, got a new timing belt installed at the next town, and continued
on my trip without incident. Not all cars are this lucky however. Still,
it may be that the top of the pistons on your engine have the "divots"
that protect them from a valve that is down at the wrong time -- almost
entirely due to a timing belt failure.

Just check with an experienced MAZDA mechanic to see if the engine
design is such that it is protected from a valve that is hanging down
after a belt breakage. You might also be able to track down the info. on
the web. Look even at an auto-parts web store for the pistons that go
with your car's engine. The appearance of the tops of the pistons might
tell you a lot right there.

Hope that helps!

On Mon, 7 Jan 2008 09:21:52 -0500, "Bob" <rkindt@hvc.rr.com> wrote:

>Anyone experience a broken timing belt on a 1988 929 engine? Son's car
>just had this happen and we are wondering what the chances are that things
>(pistons valves) 'survived? I am assuming that this is a destructive
>engine. Car was only going about 15 MPH when this happened.
>
>We would like to undertake repairing this ourselves.Anyone gone though this?
>Any advice appreciated.
>
>Thanks.
>
>
Go to this site to see if the engine is interference. Bottom right of
the page.

http://www.gates.com/index.cfm?CFID=...TOKEN=42972810

Pete

In article <47829f68.11288796@news.mts.net>, cselby@mts.net wrote:

> Go to this site to see if the engine is interference.

Not good... says Interference Engine... Yuck! I'd plan for engine damage.

I got concerned so checked my own '99 Mazda 626 LX-V6 and it doesn't say
intereference for that year and model.

Also, I checked my old '91 Ford Escort Wagon with the 1.9L 4CYL and sure
enough, it also was okay.

Thanks for the advice. So yes this is an 'interference' engine. Yuck.
Amazing how such expensive cars now have these rubber timing belts .....
shame how so many cars end up in the salvage yard because of them.
Guess my next step will be to pull the heads.


<cselby@mts.net> wrote in message news:47829f68.11288796@news.mts.net...
> On Mon, 7 Jan 2008 09:21:52 -0500, "Bob" <rkindt@hvc.rr.com> wrote:
>
>>Anyone experience a broken timing belt on a 1988 929 engine? Son's car
>>just had this happen and we are wondering what the chances are that things
>>(pistons valves) 'survived? I am assuming that this is a destructive
>>engine. Car was only going about 15 MPH when this happened.
>>
>>We would like to undertake repairing this ourselves.Anyone gone though
>>this?
>>Any advice appreciated.
>>
>>Thanks.
>>
>>
> Go to this site to see if the engine is interference. Bottom right of
> the page.
>
> http://www.gates.com/index.cfm?CFID=...TOKEN=42972810
>
> Pete

On Tue, 8 Jan 2008 20:10:30 -0500, "Bob" <rkindt@hvc.rr.com> wrote:

>Thanks for the advice. So yes this is an 'interference' engine. Yuck.
>Amazing how such expensive cars now have these rubber timing belts .....
>shame how so many cars end up in the salvage yard because of them.
>Guess my next step will be to pull the heads.
>
Or install the belt and with all the guards off, check if you get
compression in all the holes. You have to open up the timing belt
area anyway and you could get lucky. The few extra minutes to do the
belt first may be a cost saver.

Pete

Guess we were very very lucky.
With new belt installed, compression readings range from 125 to 150 PSI so I
am assuming that is normal for an engine with 130K miles.
But belt does appear a little loose/slack however, so will be looking for a
new tensioner before closing it up.
Thanks for the advice guys. Bob



<cselby@mts.net> wrote in message news:478500c2.492312@news.mts.net...
> On Tue, 8 Jan 2008 20:10:30 -0500, "Bob" <rkindt@hvc.rr.com> wrote:
>
>>Thanks for the advice. So yes this is an 'interference' engine. Yuck.
>>Amazing how such expensive cars now have these rubber timing belts .....
>>shame how so many cars end up in the salvage yard because of them.
>>Guess my next step will be to pull the heads.
>>
> Or install the belt and with all the guards off, check if you get
> compression in all the holes. You have to open up the timing belt
> area anyway and you could get lucky. The few extra minutes to do the
> belt first may be a cost saver.
>
> Pete

> Bob wrote
> Anyone experience a broken timing belt on a 1988 929 engine?
Son's car
> just had this happen and we are wondering what the chances are tha
things
> (pistons valves) 'survived? I am assuming that this is
destructive
> engine. Car was only going about 15 MPH when this happened
>
> We would like to undertake repairing this ourselves.Anyone gon
though this?
> Any advice appreciated
>
> Thanks

Hi this is my first post
Had the same problem with my 1988 929 with a belt that had only don
40,000km (2nd timing belt) Reason: Top idler pulley seized causin
the belt to self destruct due to heat build up! When I stripped th
engine to examine cause discovered ALL 3 idlers including tensione
wheel to have either marginal or shot bearings. 140K total mileag
which isn't much

SO BEWARE it looks like these bearings do not age gracefully and los
the factory packed lubrication over the years and finally fail. I'
not sure if my engine has survived but everything turns over OK - n
metallic clunks so I believe this may not be an interference engin
as suggested and hope to have the car back on the road within th
week

Mazda here in Melbourne Australia want $200 each for each new idle
wheel so I am currently trying to track down alternatives. Th
internal bearings are easy to replace and mine are NSK 6203DWAX. An
advice on economically replacing all 3 idler piulleys would b
appreciate

> > Bob wrote
> > Anyone experience a broken timing belt on a 1988 929 engine?
Son's car
> > just had this happen and we are wondering what the chances ar
that things
> > (pistons valves) 'survived? I am assuming that this is
destructive
> > engine. Car was only going about 15 MPH when this happened
> >
> > We would like to undertake repairing this ourselves.Anyone gon
though this?
> > Any advice appreciated
> >
> > Thanks
> Warmtone wrote
>
>
> Hi this is my first post
> Had the same problem with my 1988 929 with a belt that had onl
done 40,000km (2nd timing belt) Reason: Top idler pulley seize
causing the belt to self destruct due to heat build up! When
stripped the engine to examine cause discovered ALL 3 idler
including tensioner wheel to have either marginal or shot bearings.
140K total mileage which isn't much
>
> SO BEWARE it looks like these bearings do not age gracefully an
lose the factory packed lubrication over the years and finally fail.
I'm not sure if my engine has survived but everything turns over OK
no metallic clunks so I believe this may not be an interference
engine as suggested and hope to have the car back on the road withi
the week
>
> Mazda here in Melbourne Australia want $200 each for each new idle
wheel so I am currently trying to track down alternatives. Th
internal bearings are easy to replace and mine are NSK 6203DWAX. An
advice on economically replacing all 3 idler piulleys would b
appreciate

Update: I do not believe this is an interference engine as suggeste
by others
I am referring to the 1989 model SOHC JE engine. There is n
interference evident when turning cams to align with the crankshaft
as required to install new timing belt. Be very caredul to line u
marks it's easy to get this wrong due to parallex error. Sugges
using a white marker to align cam sprockets

The car is now running like a clock!

Bria