'96 Mazda Protege Exhaust Manifold Torque Specs

Hi. Just replaced a cracked exhaust manifold on my daughter's '96
Protege. All that's left is to torque the bolts down. It has the 1.6L
DOHC engine. According to the Haynes manual I have, the torque specs
are 28-34 ft. lbs. for that engine up through 1998. 1999 and later,
the specs are 14-21 ft/lbs??? About half the tightness of the cars a
few years older. Sure makes me wonder why that is?

Do these numbers sound right? I have an aftermarket manifold and I've
cracked more than one car or marine part by tightening it to spec. Can
this be a problem with the exhaust manifold? For some reason, the
local muffler shops wouldn't touch the job, which makes me that much
more concerned. They said they couldn't get parts??? The job wasn't
that difficult. In fact, I did not even have to get under the car to
do any of the work.

Any tips or advice is gratefully appreciated.

Regards,
Denis

Sorry folks. I checked the engine block and it's stamped Z50. That
and a few other clues tell me it's a 1.5L DOHC. The torque specs are
still the same, though.

Handyman wrote:
> Hi. Just replaced a cracked exhaust manifold on my daughter's '96
> Protege. All that's left is to torque the bolts down. It has the 1.6L
> DOHC engine. According to the Haynes manual I have, the torque specs
> are 28-34 ft. lbs. for that engine up through 1998. 1999 and later,
> the specs are 14-21 ft/lbs??? About half the tightness of the cars a
> few years older. Sure makes me wonder why that is?
>
> Do these numbers sound right? I have an aftermarket manifold and I've
> cracked more than one car or marine part by tightening it to spec. Can
> this be a problem with the exhaust manifold? For some reason, the
> local muffler shops wouldn't touch the job, which makes me that much
> more concerned. They said they couldn't get parts??? The job wasn't
> that difficult. In fact, I did not even have to get under the car to
> do any of the work.
>
> Any tips or advice is gratefully appreciated.
>
> Regards,
> Denis

"Handyman" > wrote in message
ups.com...
> Sorry folks. I checked the engine block and it's stamped Z50. That
> and a few other clues tell me it's a 1.5L DOHC. The torque specs are
> still the same, though.

Since no one else has answered, I will be the fuel for flames.

Torque specs often take into account the bolt strength, the strength
of the material it is threaded into, the desired clamping force, etc In
other
words, there may be more than one factor involved.

If it were mine and I were really worried, I might torque it to the upper
limit of the lower torque range figure and see if it leaks. I might then
run it
for a few days, and retorque.

You SHOULD be okay using the published specificiations, but if you
are nervous, sneak up on it.

Thanks for the info. As it turned out, the lower torque specs were for
the 1.5L. Your suggestion is exactly what I did. Torqued it to 15
lbs, ran the engine for a while, retorqued to 20 in stages, cringing
the whole time. :-) I've been hearing that cracked exhaust manifolds
are common on those cars. (?????) Been working on cars my whole life
and never heard of such a thing.

Looks like the PCM for that car may be gone too. Injectors seem to be
running wide open and I checked the sensors. The coolant sensor was
running the proper resistance, but the 5 vdc supply is not to be found.
Jeez, I'm really getting to hate that car! :-)

Regards,
Denis

wrote:
> "Handyman" > wrote in message
> ups.com...
> > Sorry folks. I checked the engine block and it's stamped Z50. That
> > and a few other clues tell me it's a 1.5L DOHC. The torque specs are
> > still the same, though.
>
> Since no one else has answered, I will be the fuel for flames.
>
> Torque specs often take into account the bolt strength, the strength
> of the material it is threaded into, the desired clamping force, etc In
> other
> words, there may be more than one factor involved.
>
> If it were mine and I were really worried, I might torque it to the upper
> limit of the lower torque range figure and see if it leaks. I might then
> run it
> for a few days, and retorque.
>
> You SHOULD be okay using the published specificiations, but if you
> are nervous, sneak up on it.