Well, I know not everyone is mechanically inclined and/or adventurous, but I pulled the engine out of my Miata a few months ago, removed the crank, had it machined, put new bearings in and replaced the oil pump. (relief valve on the oil pump was sticking open causing low oil pressure, scored the crank) Pretty much the same thing you need to do, you'll just be putting in a new crank. (and yes, I'd spend the $160 to replace the oil pump... not worth the risk to not replace it while you have it apart)

If you've got a place to work, you could do the same for the cost of a tow from Stuart's shop and parts. This was my first such experience, and I won't lie and say I wasn't a bit intimidated and unsure of myself at times, but if you take your time, follow instructions, work very carefully, and don't cut corners, this is a job you could do yourself.

 

I am currently working through the same problem on my wife's '96 Outback Sport. With her car I can't see going through all the hassle of replacing the motor or crankshaft to come out with the same 130 HP on the other end.

JB Weld should not even be considered, it's great for some things but if you try to use it in this application it will just crumble away. This was pretty easy to see after I JB'ed up the crank shaft and started trying to re shape the keyway, trust me don't waste your time.

The fix that I'm going to use is to place the key in the crank and fill the wobbled out areas with the strongest, highest heat range thread sealer I could find. Let it set up for a few days and then reassemble. This method was recommedend by a mechanic I trust. I'm actually just to the reassembly phase now so I should know by this Saturday how well it works.

Good luck Jason, and just to make it known. Replacing the crankshaft is probably the best option. If you can handle the cost, I'd ask to have the rest of the engine inspected during the rebuild as well. Might as well end up with a nice fresh motor out of the deal. Have you looked into the cost of a crate motor from MazdaSpeed Motorsports? Might be worth checking out anyway.

 

First of all... It sounds like your wife's Outback needs an EJ25T, haha.

Yeah, I talked through most of this with Stu. He wasn't comfortable with the threadlocker/QuickMetal solution, and to be honest, I wasn't either, heh. I thought about a crate motor or a low mileage junkyard motor, too. But I think replacing the crank is the middle road... How much does a 1.8L crate motor from Mazda cost?

I thought about freshening the top end, too, but from the sound of it it would add another $700 to the deal for rings, honing the cylinders, a valve job, etc... And I've already spent a lot more than I planned, heh. I figure it's only got 100k on it. It's middle aged for a Miata, right? Maybe in a few years when I'm bored I'll pull it apart and put a turbo on it.

I haven't heard from Stu yet this week, so it doesn't look like I'll make it to Brooksville. Probably just as well. I'll still need to get the tires on it and get it aligned...

 

Someone just popped up on Miata.Net with a 406,000 mile Miata. Original 1.6 engine, nothing but regular oil changes and 60k mile timing belt changes. Your car isn't middle aged, it's just getting broken in!

 

Haha, sweet. I'm getting REALLY anxious to have the car back! I got the title/reg/plate in the mail this week, and I was like "WTF is this for?" Then I was like "oooooohhh yeah. I bought a Miata!"

I've got the Azenis sitting in the living room... The smell is driving me nuts!

 

1.8 long block from Mazda Motorsports is $1950

 

Man... That's actually not too bad. I assume that's ready to run? Just fill it with fluids, bolt it to the trans, and go?

 

Longblock is typically motor with heads and most sensors, you'll still need your accessories (PS pump, AC, etc.). But for the most part, stick it in, connect to the harness and tranny, hook up all your accessories and belts then crank it up.