The easiest timing belt job I've ever done - PeachParts Mercedes-Benz Forum

engatwork · #1 01-16-2015, 09:11 PM

Had a 91 Mazda Miata in the shop this week needing cooling system rebuild (199k miles showing on clock). Went ahead and replaced water pump and timing belt. The timing belt had to be the easiest one I've ever done. Nothing to this one. I suspect the cooling system had never been serviced. The radiator was plugged up. Here is the thermostat. Surprisingly enough the engine is fine.

spdrun · #2 01-16-2015, 09:34 PM

Great drivetrains. Make sure you torqued and Loctited the crank bolt correctly and used a new key. Those motors are prone to crank pulley wobble that eventually eats the end of the crank. Other than that, they're basically bulletproof.

super SEC · #3 01-16-2015, 10:04 PM

WTF? Where they using water from a muddy creek as coolant?

tbomachines · #4 01-16-2015, 10:17 PM

I was going to guess a Fiat but almost the same thing!

INSIDIOUS · #5 01-16-2015, 10:45 PM

Quote:

Originally Posted by tbomachines

I was going to guess a Fiat but almost the same thing!

I looked twice and don't see it, where is the timing belt?

t walgamuth · #6 01-17-2015, 07:42 AM

Quote:

Originally Posted by super SEC

WTF? Where they using water from a muddy creek as coolant?

Its probably never been changed before.

ramonajim · #7 01-17-2015, 03:21 PM

Quote:

Originally Posted by spdrun

Great drivetrains. Make sure you torqued and Loctited the crank bolt correctly and used a new key. Those motors are prone to crank pulley wobble that eventually eats the end of the crank. Other than that, they're basically bulletproof.

There's a pretty strong case to be made for replacing the crank bolt on the 1.6 Miata engines (90-93, though the bolt was replaced with a longer version somewhere in 91 or 92, if I remember correctly) anytime you take it out.

engatwork · #8 01-17-2015, 05:46 PM

Thankfully I did not have to mess with the crankshaft bolt. I just had to remove the harmonic balancer and pulley.

I think this is one of the funnest driving cars I've ever driven.

ramonajim · #9 01-17-2015, 06:56 PM

You have to remove the crankshaft bolt to get the HB and pulley off.....

engatwork · #10 01-17-2015, 06:57 PM

I was able to replace belt by just removing the four fasteners that held the pulley and balancer onto the sprocket and hub.

ramonajim · #11 01-17-2015, 09:33 PM

Guess I just assumed you'd be replacing the front seal while you were in there - for that, the crank bolt must come out.

engatwork · #12 01-18-2015, 07:59 AM

I did a lot of reading/studying and came to the conclusion that I'd be opening a can of worms if I pulled the crank pulley. Everything I read said if it is not leaking to leave it be. This particular model has a bad rep in regards to the threaded part of the crank where the fastener screws in.

Mr.Kenny · #13 01-19-2015, 11:25 AM

Miata Timing belt Tip: Don't add 'extra tension' on the idler tension bearing; the tension spring is just the right amount of pressure on the timing belt before tightening it.
Otherwise your idler bearing will make noise and wear out quickly.

t walgamuth · #14 01-19-2015, 02:01 PM

Quote:

Originally Posted by engatwork

Thankfully I did not have to mess with the crankshaft bolt. I just had to remove the harmonic balancer and pulley.

I think this is one of the funnest driving cars I've ever driven.

Its a lotta fun. You can race people all the way to work weaving in and out of traffic and the cops just don't even see you at all. Don't explore the actual limit of adhesion on the street though cause it might leave the road backwards if you get too aggressive. Fortunately there is plenty of fun inside the limit.

I like it because there is enough power to kick the rear out a bit taking off and turning 90 degrees at the same time.

Simpler=Better · #15 01-26-2015, 07:18 PM

Quote:

Originally Posted by super SEC

WTF? Where they using water from a muddy creek as coolant?

That looks like my truck's cooling system...after 2 flushes.