Major Miata Maintenance

[Loren]

Not sure when this is going to happen (probably within the next 2-3 weeks). As usual, this is mostly just a place for me to organize my thoughts and information.

If you've been keeping up, you know that I desperately need to replace the water pump on my Miata. And on a Miata, that involves replacing the timing belt. And those of us who are knowledgeable enthusiast types know that by the time a Miata reaches its second timing belt interval (120-150k miles) an awful lot of other parts should be replaced at the same time. Belts, hoses, seals, etc.

So, I've got a 99 Miata in need of this treatment. And Ken's 94 is right there with it. We're going to do them both at the same time.

Lucky me, I've done this before, and documented a big ol' list of stuff that needs to be replaced. And I'm working out where to buy them as simply as possible from reliable sources. Ordering all the stuff below tonight... x2!

A good portion of what we need is here in this Timing Belt & Water Pump Kit from Amazon: ($81)
Timing Belt
Timing Belt Tensioner Pulleys
Camshaft Seals (2)
Front Crankshaft Seal
Water Pump

Also from Amazon:
CAS O-ring for the 94 ($6)
Camshaft Plug for the 99 ($16)
Silicone Sealant ($5)

From eBay:
Cam Cover Gasket ($30)

Flyin' Miata has a good Hose & Belt Kit: ($189)
Accessory Belts
Radiator Hoses
Heater Hoses
All the other stupid hoses
Clamps
Thermostat & Gasket
Radiator Cap

Other Stuff we'll get locally:
Coolant
Engine Oil & Filter (I have two filters)
Engine Cleaner
Brake Cleaner

Other stuff I'm replacing on my car:
Cooling Fan (installing a Spal fan into the stock housing)
Fuses for both cooling fans

Assuming we don't run into anything else that's broken... that should get both of our engines good for another 60-80k miles!

[Loren]

A month later...

Finally got around to doing this today. Couldn't coordinate a good time with Ken, so we just did my car today. Or, at least started on it.

10-15 years ago, Miatas were super-easy to work on, and a half-day job took a half-day. Now the cars are older... there's always some complication.

This time, it's rusty pipes. I'd thought of everything but that! I have all of the replacement hoses on-hand. But, several of the steel pipes that they attach to are just plain useless!

The good news is that they're all replaceable parts. And the parts are available.

The bad news is that they're stupid expensive!

Thermostat Housing - $65
Coolant Inlet Flange - $127
Coolant Pipe - $67 + $14 shipping

That's over $250 worth of parts... that I don't have. So, my car sits disassembled in the garage. (but, at least it's MY garage)

For those kind of prices, I'm considering just repairing a lot of the pipes.

The coolant pipe is a steel pipe that runs from the back of the water pump under the exhaust manifold to the back of the engine to connect to the heater core. It's a pretty straightforward piece, and I could probably make this one work. But, I don't see it having more than 5 years of life left. I'll bite the bullet and replace that one.

The other two parts are cast aluminum with 8mm (rusted) steel hose bungs stuck in them. I can remove those bungs, thread the hole for 1/8 NPT, and put a 5/16" hose barb in there. I can get the 1/8 NPT - 5/16" hose barbs for about $5 each. Even paying for the 1/8 NPT tap that I'll need... WAY cheaper than $190 worth of new parts. Gonna go with aluminum barbs to avoid problems with galvanic corrosion. Aluminum into aluminum should stay happy.

Photos are always fun, so let's look at some!

Front of the engine is A-OK! All cleaned up, oil seals replaced, ready for the waterpump to go back on. (and the thermostat housing, timing belt, and all those silly covers and hoses and stuff)


On the right side, we've got the oil cooler lines, which are in good shape. The ones off the of throttle body are okay, too.


Back side of the engine is the source for the oil cooler and throttle body hoses. It's got some significant corrosion on the end of it, but it's intact enough to use.


Other side of the back is the heater supply. It's cast aluminum and a little grungy, but fine.


Heater Core pipes. Ugh. They used to make these out of brass. Looks like these are aluminum. Not sure why one of them is mangled. But, I'll clean them up a little more, they'll be okay.


And these are the problem children:


Close-up of the completely rotted pipe ends:

[Native]

Solid progress, but what a drag.

[jev61]

Call Tom at The Parts Group, he is going out of business. (386) 446-0051

[Loren]

Thanks, Joe. I figure any used part is still 15 years old at this point. Not going to bother with that. I got a new replacement for the long steel tube. The others I've pulled out the steel inserts and will be replacing them with aluminum threaded fittings.

All the parts have arrived. Just waiting on my tap. Should have that all done either Monday or Wednesday. Then sometime over the next week I'll get the car reassembled.

Someday I'll get to enjoy this car.

[Loren]

Made some progress on Friday.

Got all of the holes tapped and fittings installed. Looks pretty good. I used a standard plumbing pipe fitting compound on the threads. Container says it's good to 500 degrees F and for oil/fuel/etc. Should be good. I've found the stuff works better and easier than teflon tape.



Water pump and timing pulleys were installed Friday. I found it amusing that I was rapidly alternating between 4 different products to complete that work. Pipe compound on the pipe threads, anti-seize on some of the more rust-prone bolts (water pump), RTV sealant on the gasketed surfaces, and blue Loctite on the critical bolts.

Saturday, Philip and Ben came by to help. We weren't working very quickly, and lunch was involved. But, shortly after Ben left, I was able to do a "minimal assembly" engine start. (no radiator, no water) It fired right up with no strange noises. That always makes me happy.

So, I proceeded to fit the radiator and hoses. Filled it with tap water (as soon as I'm sure there are no leaks, I'm going to put some cooling system flush through it... THEN I'll fill with distilled water and coolant). Restarted and warmed it up. Only one leak!

Apparently, I wasn't paying enough attention when I fitted the thermostat housing. I do remember rushing through that. I thought the thermostat shifted, and that I'd gotten it reseated. But, I did it by feel, and didn't LOOK at it. So, the thermostat cover has part of the thermostat wedged under the bottom of it and it didn't fully seal. Will be an easy fix. I got it all the way up to operating temp, and no other leaks! I'm cool with that!

So, tomorrow or Monday, I'll get that leak fixed. Then I'll finish the radiator install, and a few other small details. Will be ready to autocross on the 28th!

[Jamie]

I found it amusing that I was rapidly alternating between 4 different products to complete that work. Pipe compound on the pipe threads, anti-seize on some of the more rust-prone bolts (water pump), RTV sealant on the gasketed surfaces, and blue Loctite on the critical bolts.

Better be sure you didn't mix up those!

[Loren]

Survived the drive to Lakeland and back and an autocross without issue. Car is running great, no leaks. Well, there is a little drip of oil in the garage. I'll keep an eye on it, but probably nothing to worry about.

Drained the radiator flush out of the cooling system today. Flushed with hose water, drained that and filled with 1.5 gallons of distilled water. Warmed the engine up, let it circulate a bit, and then drained it all out. Filled with 1.5 gallons of distilled water again. Warmed it up, drained it again, and then refilled one last time with distilled water. I'll run that for a few days or a week. Then drain once more and fill with proper coolant mix.

Pretty much a wrap for the major maintenance! I still need to remove the intake manifold and clean the EGR passages. And I should probably think about valve adjustment at some point.

[Jamie]

I did notice my rear brakes are getting a bit thin...ordered new bits last night. Hoping to put everything else off until 300k, which will probably arrive mid-summer, when least convenient.