Dying engine. What should I do?
 

Hi there! My name is Josh and this is my story..

I recently bought my first Miata, is a 2000 Nb1. I am a total noob at anything Mazda related, I’ve been into cars for a while but this is my first non european one. I bought it cause I wanted something fun and reliable to build, so yeah it was supposed to be a project car until I had to sell my 135i and then it became my daily.

With that being said, when I bought I knew the engine had seen better days, it has 197k miles at this point and it’s burning at least 2qt of oil a week. I have yet tried to do a compression test but Im sure that’s gonna make me real sad lol

So I’ve been considering all my options and wanted to see what you guys think. I’ve read some before posting and excuse me for my ignorance, but I just don’t know much about this cars. So far this are the 3 options that I’ve been falling for..

- Rebuild my engine
- Buy a 01-05 engine and swap my head into it
- Buy a MSM engine

I would like to hear pros/cons and what you guys think. I am basiylooking for the best “bang for the buck” and not necessarily the cheapest route. I would still like this car to be my project platform and have plans to turbo it and do some performance upgrades regardless of the engine I use. At the same time I can’t really afford to stop the car for too long as I need to make it to work in order to have money for the build lol

I would definitely appreciate any guidance that you guys could provide.

Buy another 99-00 engine.

You sure it's not leaking anywhere?

This, and swap the whole engine. You can do it in a weekend for a couple hundred bucks worth of harbor freight tools.

Yup, swap a 99-00 enginen in, then build yours.

Are you sure it's not just a leak though? My 99 leaks 3/4qt every 500mi due to a botched main seal. Otherwise compression and everything is perfect.

What you should do immediately is find out what's causing you to loose 2qt/week. Compression test is the easiest as you don't need an air compressor handy. Leak down will give you a more precise picture on what is going on inside your engine. If your compression is fine then it might just be a big leak through a seal. That is what you want to hope for as that will be your cheapest route for losing that much oil. If your compression is bad then you need to find an air compressor to do a leak down.
Regardless, if you want to keep this car as a daily then you're going to need to learn a bit more about your engine very quickly. Luckily for you just about everything ever done to a Miata under the sun has been documented here for your learning pleasure.

If your engine actually uses 2qt per week. You should be able to see oil smoke. Does you car smoke under full load, high RPM or when you let go of the throttle? If you don't see any smoke under any circumstance it is loosing oil somewhere else and you should look at where it is going. Look for smoke in your rear view mirror, or let a friend watch while you drive past him. He should see and smell it.

You can have perfect compression and still use lots of oil. If anything the pooled up oil on top of the piston actually helps the compression numbers.

If it is the oil control rings and you are putting in a new engine. Just put in the VVT engine and run it with the VVT disconnected. Should be easier to find and when you are actually going to turbo it you can wire in the VVT to your stand alone and make more low end torque.

Thank you all for your input. I forgot to mention, yes! Whenever I go full throttle and pass 5k revs my engine starts to smoke. I haven’t seen any leaks so that’s how I deducted that my engine might have some really worn internals. Hopefully I’ll be compression testing it this weekend and will let you guys now.

Also, what numbers for compression should I be looking for? Just got offered a 99-00 engine with 72k miles on it and the following compression test numbers: 180-180-185-175 and a MSM one without the turbo system with a bit more mileage 122k and 195-200-200-205 for around the same price. I have tried to research the difference between the both but I couldn’t find anything to justify the difference in compression as they are technically the same engine from the head down. Please correct me if Im mistaken.

Just go get that 72k mile engine. Swap it in. EZ PZ