Disassembly

Before you begin, read Cleaning and check out my comment on the kiddie pool. Now would be a GREAT time to have one.

Once you have your core you're going to want to tear it apart. This is basically a no-holds barred procedure. Very little does NOT get removed and disassembled, and provided you keep the parts you remove organized you could theoretically just tear into the engine at this point. But, if you have some patience to read on, I can share a few tricks that make the process faster and easier.

First, a few tips:

1. A small pile of quart and gallon Ziplocs (Slide-locs are easier to close with dirty hands) can help keep parts organized. I like to keep nuts and bolts with the parts they attached to. This also keeps moisture away from the parts, so they don't rust until you're ready to use them again.
2. Save everything. You're going to toss a lot of what you remove: many O-rings, washers, and springs get replaced during the rebuild. However, not ALL of them get replaced, and even the ones that do are a record of sorts of what happened in an engine.
3. I'm a huge fan of disposable gloves. You can save a lot of wear and tear on your hands by using them, and it sure makes it easier to grab the camera for a photo of your work if you can have a clean hand instantly.

The Mazda Workshop Manual calls for the engine to be immediately installed on an engine stand after it's removed from the car. I don't know about yours, but MY engine stand is a dinky Harbor Freight number with an aftermarket adapter plate. It was so poorly made that I had to use a die-grinder to enlarge the locator pin hole because wasn't in the right spot. I figured it would hurt to remove a few heavy objects before mounting it.

Most of the accessory devices come off fairly quickly, especially if you follow Mazda's steps:

1. Remove the A/C compressor and power steering oil pump brackets/studs.
2. Remove the water pump, smog pump, and alternator.
3. Remove any air pipes that are within easy reach, like intercooler and turbo air hoses.

I only mounted the engine onto the engine stand after I had removed these items.

Once this is done, mount the engine on the engine stand. The stand should attach to the left vertical side of the front iron - at least three studs along that area should match up with your adapter plate. Make sure the adapter plate 'points' toward the center iron, or the engine will not be balanced on the stand. And don't trust it anyway!

Remove the turbo by first removing the aluminum air pipes to the left (cobra-head) and on top (Y-shape) of it. Then remove the multi-line vacuum hose assembly and bracket to the right of it. For our purposes, you can just cut any rubber or plastic hoses where you encounter them. Some are very hard to get off their fittings, and we won't be reusing any of them.

There are several actuators to the bottom-right of the turbo assembly. The one furthest to the bottom and right (“Turbo control actuator” in the FSM) comes off next by unbolting it and removing the retaining clip from its arm. Finally, you can unbolt the oil drain hoses and the water hose. After that, the remainder is all one turbo assembly - don't start dismantling it. It'll come off in one piece that you can (try to) sell on eBay.

Well, HOPEFULLY it will come off. These particular mounting studs see a LOT of heat and stress. I found it extremely difficult to remove them - WAY more difficult than the famed flywheel nut. Despite liberal use of penetrating oil and a long breaker bar, I still managed break off one stud. Fortunately the part that broke was inside the turbo mounting flange, which I didn't need any more AND wasn't critical to an eBay resale.

When you're done, you should have quite a pile of turbo parts!

The intake is next. It supposedly can come off in one piece, but I found it much easier to first unbolt and remove the upper intake manifold (UIM), then remove the lower intake manifold (LIM) separately.

At this point you're going to expose a rats-nest of vacuum pipes and solenoids. Now you can have at it - everything that has a bolt, loses it, and the core should magically appear from underneath the tangle after after 10 minutes' work.

Expose the entire core as best you can. Remove the oil pan, water pump (if you haven't already), oil metering pump (from the side of the front cover - but don't crack open the front cover YET), oil filler neck and filter, and any other hangers, brackets, and other parts you encounter. When you're done your core should be pretty clean!

Now stop and take a breath. Many of the components you've been removing are things you won't be reusing, so you're probably getting faster and faster. But from here on, you DO need the items you remove. They're also less rugged. This is a perfect time to catch your breath and do an external inspection.

Look for obvious signs of stress - cracking or bulging in the housings or irons, indications that porting work was performed by somebody else (non-stock exhaust or intake port shapes are visible at this point), and so on. If you rotate the engine at this point, you should clearly see the rotors through the exhaust ports, and hear “chuffing” sounds as each exhaust pulse exits its rotor housing. If you don't, well, there's nothing you can do about it now, but at least you're going in with open eyes.

By now your engine core should be pretty stripped down - no obvious nuts, bolts, brackets, or other parts should be visible. If there's anything left that you can easily reach, take it off now.

The first item to remove from the core is the front housing. Remove the eccentric shaft lock bolt, and set it aside along with its bypass valve and spring; you'll be modifying these components later. Note that if you use a normal socket wrench you'll need to find some way to keep the eccentric shaft from turning, such as by bolting something onto the flywheel. I used an impact wrench, and was able to skip this step.

Remove any other bolts on the front housing, then gently pry off the cover with a pry bar / screwdriver. Be sure you don't scratch the mating surfaces. You'll need them to seal well when you re-assemble the core.

Underneath the front cover is what's called the “stack”. The oil pump and its accessories are bolted to the bottom of the front iron, and the counterweight and a series of spacers/bearings are bolted just next to them. I strongly advise you to keep these particular parts in Ziplocs. You definitely don't want any dirt or dust in them, and it's easy to lose some of the small parts. Pay particular attention to the woodruff key on the oil pump. It's small and easy to lose.

One common and very handy recommendation is to zip-tie the “stack” together, in the order in which it was mounted. The “stack” is everything under the oil pump nut and washer - the drive gear, pump, counterweight, various bushings, and bearings/washers.

If you happened to buy an automatic, congratulations. The flex plate will come off easily with bolts, and it's the right part to attach the PSRU to. Skip this section.

There's a lot of drama and near-religious lore attached to removing the flywheel nut. On a 3rd-gen engine it's installed with 450-ft-lbs of torque, and you're supposed to put on a huge breaker bar plus jam the flywheel in some way so it can't turn. There are YouTube videos and forum posts with all sorts of hints on how to do this.

Or you could do what I did. Hit it with an impact wrench. My Husky 650 popped it off in two seconds. I didn't even have to block the flywheel from turning. Yawn.

Removing the flywheel itself can be a bit more complicated. A puller is very helpful, but don't forget that you're pressing against the end of the eccentric shaft with it. Make sure you back up the “point” with a large socket or other sacrificial item under the puller's center shaft to avoid damaging it.

I've seen the Mazdatrix Guide that shows how to 'pop' off the flywheel with a tap or two from a dead-blow hammer. Well, not only did that NOT work for me, but BEATING on it didn't work either. My flywheel was well and truly stuck on.

What finally worked was when I pointed my flywheel straight up, wrapped a rope around it, and hoisted the engine by the rope just enough to put the engine's weight on the flywheel. Then I used the puller to apply force to the end of the eccentric shaft. Then I put a pair of pry bars into the gap at the edge of the flywheel and applied weight to them. Then I “GENTLY” tapped the flat spots of the flywheel, as Mazdatrix advises. None of that worked, so I heated the center of the flywheel with a torch. That didn't work, so I sprayed in some penetrating oil. After an hour or so of this, lifting, “tapping”, prying, and heating all together did the trick.

It should be obvious, but while you're here, remove the counterweight and don't lose its woodruff key.

Mazda has a very specific order in which the tension bolts are to be removed and re-installed. Although there is no hard evidence that this is critical, anecdotally all of the experts agree that it's probably a good idea to do.

I have a very handy technique for doing this kind of thing. Wipe the head of each bolt with a rag and some acetone to remove accumulated grease and dirt. Then, get this, use nail polish. That's right, nail polish. It's cheap, it comes in a million colors (yellow and magenta are nice high-contrast colors for marking parts), and it provides a very durable mark, but is still removable with acetone.

However, I have to admit that I was losing my patience at this point. What I actually ended up doing was taking a long sheet of cardboard and duct-taping each bolt to it, in order. This ended up not being a perfect organization solution, and I wouldn't do it again - but anything you do that 'works' is fine.

The remainder of the disassembly sort of writes itself. Pull off the rear iron, its rotor, any seals/springs that fall out, and then the rear housing. Then pull off the center housing, being careful not to damage the eccentric shaft with it (you'll need to lift the e-shaft an inch or so). Repeat the process with the rear rotor and its housing. Mark the front and rear rotors in some way - a Sharpie works well.

As I said earlier, save everything, even O-rings you KNOW you're going to trash. It's all reference material that you can use to do forensic analysis into what the engine has gone through before it got to you.

Second, although I recommend replacing all of the seals and sealing pieces, Mazda does call for being able to reuse them if they meet the specs outlined in the FSM. The reason I don't recommend this is because we both know where your engine came from - it came from “anywhere”. It was probably an end-of-life pull due for a rebuild anyway, it probably sat a while, it could have been overboosted, overheated, run without coolant or oil, etc. Even if it passes inspection you still don't know what it went through. Reusing an apex seal to save some cash? If you are reading this guide you probably don't know enough to fully evaluate whether your seals can be safely reused. Replace them.

But keep the old ones, anyway, and I recommend even following Mazda's instructions on organizing them so you can tell which rotor and seal location they came from. I recommend watching Pineapple Racing's video guide (below) so you can identify seals, then organizing them so you can refer back to them later. Consider: sometimes you don't know what the rotor looks like under all the carbon accumulated on it. When you clean it up and find a gouge, wouldn't you want to be able to look at the matching seal to see if it has any evidence of damage?