red '93 mx-5 journal

[chromal]

I'm going to post future updates re: my miata here in the Miata subforum for now on.



Not too much is new right now, have been procrastinating projects for warmer weather and melted snow, though in recent weeks there have been a few breaks in the weather. I took the Miata out for a few drives in the foothills and get to know it better. All said, I've put about 1000 miles on it since January, essentially most of that west of CO-470.



Finally seemed like it was time to do something about the gaping hole where the OEM audio headunit was. The previous owner had prioritized body work after buying it with a custom audio setup freshly removed. Fortunately, the factory harness points were intact. The previous owner generously included an OE audio harness connector, as well as what seems a really quite decent CD-MP3 Kenwood head unit.



Fortunately, the head unit harness wires had labels affixed and I had the factory service manual for the car side audio connectors. I set up the front L/R door speaker channels, ACC, and B+ connections by soldering and then insulating with head shrink tubing. There was a separate ground wire with the car's audio harness that I used a wire nut on.

Around this point, I discovered there was a fried voice coil in the driver door speaker, an Infinity Kappa 62.1i 6.5" 2-way full range driver. Doesn't seem easy to source an identical replacement for just the blown speaker. Both door speakers will be replaced with something else, not sure what, yet, beyond it will be decent but on a tight budget.

There's a short list of things I want to work on soon:
timing belt, water pump, coolant, front engine seals
possibly bent hood hinge
popup headlight linkage bushings
center brake light
cabin rear deck carpet
right rear rust

and stuff I hope to address before next winter:
engine rear seals
transmission seals
differential seals
air conditioner
hard top shell repair, hard top window

[Saul_Good]

Keep um comin. Hope to see this at a track one day.

[chromal]

I decided to make a run at the timing belt / water pump overhaul on the miata this Saturday. Overall, most of the work Saturday was routine, but time consuming. Because I was expecting to do the water pump and front seals, I pulled everything off down to the cam shafts and crankshaft. I'll be replacing OE equipment using a Gates timing belt kit (with new spring, tensioner pulley, and idler puley) and a Gates water pump (with two new gaskets and an o-ring).









A considerable amount of oil sludge had built up around the main timing pulley/cog. A lot of the cover panels came off a bit sludgy/greasy/dirty, too. To the credit of the design, the timing belt was not greasy to the touch-- perhaps any leaked oil was flung off the timing cog by centripetal force? I cleaned the timing belt area with some B-12 chemtool and lots of scrubbing.

While trying to get the old crankshaft seal off, I tried the old 'wood screw' trick to extract it. this did leave some marks on the polished surface of the crankshaft's nose. At the suggestion of my roommate, I used a piece of emery cloth he provided to try to smooth/polish the scratch on the crankshaft. It seemed to help, but before long, I had a new problem. When trying to insert the new crankshaft seal, I managed to get it to catch its lip on the crank nose, bending backwards and tearing. After a trip to the auto parts store, and using a sheet of plastic I cut from a party cup, I slipped and then tapped the seal back onto the crankshaft and into its housing.

The camshaft seals were supposed to be much easier, but I quickly determined that the replacement cam seals I had were .. something else. Perhaps more crankshaft seals with another part no., not sure. Wrong part. I put the existing cam seals back in, with a dollop of automotive high temp silicon sealant. I figured I'd be extra careful as I tightened down the front camshaft holder. I pulled out my torque wrench to do it right, but the spec is low, like around 120 lb-inches (~10 lb-ft). I missed the click from my torque wrench, overtightened one diminutive bolt and snapped it off in the cylinder head. FORTUNATELY, I was able to extract it from the hole using a chisel like a screwdriver, and was able to verify with another bolt that the threads in the cylinder head had remained intact somehow. I'm starting to think about digital torque wrenches, or should have trusted my instinct with the regular socket wrench. Either way, fail on my part, the resolution was lucky; the bolt had bottomed out and sheared. It was loose on the threads within the recess, and it came out without a struggle.

For the time being (since I could add the missing bolt almost last), I wrapped up installing the new water pump, timing belt idler and tensioner pulleys (and spring), and the belt. The old tensioner pulley and idler pulley were showing the age, with a little squeal or roughness, though they hadn't actually failed. Wrapping up the new timing belt install, I kept getting the intake cam off by one tooth, but finally got everything in order, and following service manual proceedure, verified timing and belt tension.

By this point is was dark. Figuring I was at a good break point for the day, since the rest of the work was all reassembly, I stopped there. Hopefully
after a trip to Big-R or Home Depot, I will have a suitable replacement cam holder bolt. I'll post again when I've finished reassembly and testing.

[chromal]

I decided to make a run at the timing belt / water pump overhaul on the miata.
Overall, most of the work Saturday was routine, but time consuming.
Because I was expecting to do the water pump and front seals, I
pulled everything off down to the cam shafts and crankshaft.
A considerable amount of oil sludge had built up around the main timing
pulley/cog. A lot of the cover panels came off a bit sludgy/greasy/dirty, too.

While trying to get the old crankshaft seal off, I tried the old 'wood screw'
trick to extract it. this did leave some marks on the polished surface
of the crankshaft's nose. At the suggestion of my roommate, I used a
piece of emery cloth he provided to try to smooth/polish the scratch on the crankshaft.
It seemed to help. When trying to insert the new crankshaft seal,
I managed to get it to catch its lip on the crank nose, bending backwards
and tearing. After a trip to the auto parts store, and using a sheet
of plastic I cut from a party cup, I slipped and then pounded the seal
back onto the crankshaft with a 32mm socket. Well, most of the way,
the rest was tapped in with a chisel via an impact surface held against the seal.

The camshaft seals were supposed to be much easier, but I quickly
determined that the replacement cam seals I had were .. something else. Perhaps more crankshaft seals with another part no., not sure. Wrong part. I put the existing cam seals back in, with a dollup of automotive high temp silicon sealant. I figured I'd be extra careful as I tightened down the front camshaft holder. I pulled out my torque wrench to do it right, but the spec is low, like 120 lb-inches (~10 lb-ft). I missed the click from my torque wrench, overtightened the diminutive bolt and snapped it off in the cylinder head. FORTUNATELY, I was able to extract it from the hole using a chisel like a screwdriver, and was able to verify with another bolt that the threads in the cylinder head had remained intact somehow.

For the time being (since I could add the missing bolt almost last), I wrapped up installing the new water pump, timing belt idler and tensioner pulleys (and spring), and the belt. I kept getting the intake cam off by one tooth, but finally got everything in order, following service manual proceedure for verifying timing and belt tension.

By this point is was dark. Figuring I was at a good break point, since the rest of the work was all reassembly, I stopped there. Hopefully after a trip to big-R or home depot, I will have a suitable replacement cam holder bolt.

[chromal]

Where we left off yesterday, I had just finished installing the new water pump and timing belt.



After snapping a few photos, I ran out and found a m6-1.00x40 grade 8 bolt and washer that seemed a suitable match. $2.97 total for several of each at Big R.



One of those bolts is not like the others. After this, I started installing the timing covers, bottom up. I didn't have new rubber gaskets for these, and so more high-temp silicon sealant, particularly on the the timing covers that sit over the block. I did use a new valve cover gasket, with sealant as specified in the field service manual. Hopefully between this and a planned switch to 5w-40, there'll be a lot less oil seep.

The rest of the assembly was straightforward. For the time being, I have left the air conditioner belt tensioner pulley bracket off of the engine, as it is missing its pulley. If I'm lucky, a failed pulley and missing belt are all that's wrong with the air conditioner...

I filled the coolant system with some 1-year-old Zerex G-05 coolant I had drained from the SAAB when I replaced its engine thermostat a week or two ago. It took the better part of a gallon, or maybe 2/3 of the miata's stated coolant volume, to fill; the remnant of the total was the old stuff still inside the engine/heater/lines and the expansion tank's volume (but I had cleaned that out).

Besides the partial flush, I figured I'd have a chance to check the coolant hoses, which might not have appreciated being removed and remounted. In fact, the lower radiator hose may not be forming a good seal on the hard pipe it mates to, so I may replace that in a week or two as necessary, along with another coolant drain down, distilled water flush, and then fresh Zerex g-05 coolant.



Finally reconnecting the battery, I fired it up. Sounded good, no apparent leaks. I let it idle up to operating temperature until the radiator fans were cycling, and not seeing any problems, drove it the 12 or so twisty mountainous miles to Safeway and back without issue. I don't think the old water pump or timing belt / pulleys were even near failing, but now I have reset the clock on those at 144450 miles, and hopefully enough of the front seals to keep the timing gear clean and dry until a deeper engine overhaul is called for.

[RX-7 Chris]

looking good.

[chromal]

odo 144750ish.

I never really finished the last job; there were some related loose ends that required follow-up. Basically did it all again (remove radiator, timing covers, valve cover, etc.), though I left the new water pump in place. I merely tightened the pump's four bolts down further (was not close to torque spec here). Re-replaced front main seal with a timkin brand that fit much better than the national brand seal I bought from O'Reilly Auto. There was reason to believe my original installation was leaking oil into the timing area, and it was certainly getting flung everywhere. This time around, I used a 1-1/4" PVC pipe coupler to drive the seal, much better. Also replaced one camshaft seal, just because I had an extra seal lying around that I failed to install last time.

Replaced the air filter box, the original had a crack it in from this miata's checked past.

Replaced the lower radiator hose, sanded corrosion off the mating surfaces of a connecting hard pipe, and then replaced another coolant hose that runs from the hard pipe back to the engine.

Now running proper G-05 coolant.

Do it right or do it twice, I guess. All said, the timing stuff was much quicker the second time around, though. Something to be said for experience. This all is a bit too wildly disorganized the first time through, and the results spoke for themselves.

Once I remembered to reinstall the PCV hose, the car was running as well as ever, hopefully with less leaking. We'll see..

[Huzer]

I haven't decided if I'll do a preventative t-belt change now or in the fall/winter. I do have a CAS leak, and definitely need a new valve cover gasket. But thanks for the great reference pictures for when I get around to this job.

[Saul_Good]

This site has some cheap advice to up the performance of your NA. Read the one regarding the MAF specifically.

http://www.solomiata.com/CheapHP.html

[chromal]

Huzer, hopefully yours is a little cleaner. Sorry I didn't take more pictures, I should just wrap my camera in plastic wrap or something and give it the full photo treatment!

The solomiata CheapHP page is right up my alley. I'll have to try the timing mod the next time I'm in there.

I may be in there again, I still seem to have a slow leak somewhere, and it seems to be coolant. Now I'm second-guessing the water pump gasket....

It's really not a hard car to work on. This would be brutal with the engine in-situ and without a lift on the SAAB, and the Civic is annoying because you have to support the engine and remove an engine mount to get the timing belt off or on. On this 1.6 NA, remove the front bumper cover, the radiator assembly with fans and shrouds in place, and air intake assembly to give myself some space to work, then have at it. Most annoying thing is main pulley bolt is 21mm, an odd size I don't have in my socket sets (I borrowed one), and the state of my front timing covers. If I have to go in there again, I want to replace those; they don't mesh very well with one another any more...

The hard reality is that I can see pretty much every other seal is shot and seeping to some extent. Although I can do each in turn in-situ, what would make me happiest would be to remove everything and clean it all up and overhaul all seals. To some extent, that describes the state of my '98 civic hatchback. I hate leaking oil pan gaskets a lot.

[Huzer]

Since it jumps out at me, what is this part? I noticed on my firewall that something seemed to be missing, and this is it.

[erod550]

My guess would be an aftermarket horn that's louder than the factory one. Upgraded horns are a common mod on Miatas to make sure you can let those SUVs who ignore you know that you are there. It's why I put air horns in mine, but my wiring keeps having issues so I haven't had a working horn for a while, which means I have to drive even more defensively in my Miata, lol.

[Huzer]

I was thinking the same thing...horn/alarm. In that area, I have a couple of unplugged holes and some worn off paint where something used to be.

[RX-7 Chris]

That is the siren for an alarm system.

[chromal]

Yeah, it's an aftermarket alarm and wireless lock system that came with the vehicle. I probably want to remove it, probably, but haven't yet tried to determine what it will take to disconnect it from the car's ignition system. I guess as long as it isn't in my way, I'll leave it be for now...