abesRX8

Ok everyone I am at the point where its decision time for me, and I need to make a move one way or the other ASAP. I also apologize in advance for the long post. The decision I need to make is simple but complicated. Do I buy a used engine from a Junk Yard $1.8-$2.5k with 50k or less miles, or rebuild my current engine with the laundry list of unknowns but a high potential to save money in the end. I came come up with some pros and cons of each below the next paragraph.

Here is a little about the car and where I am at right now. My 8 is currently not my only vehicle and now I mainly use it for autox and Sunday drives through the mountains, but due to the following I have not been able to do these things anymore. I am the original owner of my 8 that I bought new back in 2006. Now she has 145k on the very tired original engine. She is still pretty peppy but I can feel she is starting to lose power, having hard hot start issues, and all the symptoms of compression loss. Before you give me a laundry list of things to check/fix/change to be sure it’s not the engine, trust me I have done everything (coils,plugs,wires,starter,seafoam,etc…) to keep it running up to this point. I have not gotten a compression test because I am 100% sure its low on compression, the local dealership to me does not have the equipment, and the closest one is over 100 miles away and charges $150 for the test.

Used Engine
Pros:
No teardown & rebuild required
Limited down time
Known running engine
Known price point

Cons:
Now way to know how long will it last
Unknown mileage (I don’t care what I am told, I don’t trust most people)

Rebuild Engine
Pros:
Potential lower cost
I will know exactly the condition of the engine
Great learning experience for me
Potential to port

Cons:
Need for new housings…This is my biggest concern, with this kind of mileage there is a good chance the housings are flaking and it is $1,400 for new housings.
Down time during the rebuild
Possible higher cost than a used engine

I honestly would love to get her back and running with a used/rebuilt engine for under $1400 if possible. Because down time isn’t a huge issue and this isn’t my main mode of transportation, half of me wants to try the rebuild and see how cheap I can get away with it, but the other half just wants to spend a little extra at get her on the road asap.

Now I ask for everyone’s recommendations, thoughts and experiences with this. Also how common is it that the housings are bad in a good running engine with this much mileage?

Loki

iTrader: (1)

Junkyard engine: how long before you have to rebuild it?
Engine rebuilt by you: how long before you have to rebuild it again?
If it was me, I'd pay a bit more to have an engine freshly rebuilt by a pro.

To rebuild an engine and have it turn over is one thing, to rebuilt it and have it last another 145k, that's the difference between shadetree and a pro. Just sayin.

abesRX8

I completely agree, and these are some other points I am still thinking about.

The biggest thing for me is that I absolutely hate having something done that I did not do myself. I have rebuilt & blueprinted many conventional engines for FI & NA applications, but have never done a rotary. I am very confident in my abilities and believe that if I take my time and do my research I can pull it off with the best of them.

I guess I have to be willing to accept that the margin of error is significantly smaller and the chance of successfully rebuilding one out of the gate that will last 145k is even smaller. To give credit to your point I am still struggling with this decision despite my experience.

Does anyone have thoughts of the probability of the housings being flaked and unusable with the amount of miles on this engine?

CRAZ8

Is your 8yr/160k warranty up? If not you should get a new engine from dealer if she doesn't pass compression test.

abesRX8

Unfortunately yes, she is an 04. I got it as a dealer demo with a little less than 2k on it back in 2006. It sat on the lot for almost 2 years before I bought it.

mehow

I bought a project RX8 early this year with the intentions of rebuilding the engine myself. Unlike you I didn't have any previous engine rebuild experience. I opted not to get a mazda reman or used engine with the logic that I could do it not necessarily cheaper but better myself. By better I mean that I could invest more of the money in newer parts...

I pulled the engine and took it apart. Turned out both housings had an unacceptable level of flaking. I replaced them along with all the other wear items, all springs seals etc... I made a stupid mistake during assembly which may be the source of my problems now.

The rear rotor is about 40PSI less than the front, I'm about $3500 into the engine rebuild, pulled it apart for the second time and I have no idea where I went wrong.

I don't know if I'm ready to throw in the towel yet but if I could do it again I would get it rebuilt by a pro. Either way you go I hope your experience is better than mine.

abesRX8

Stories like this really discourage me, I really hate this happened to you sir! I guess I am stubborn and would rather break it myself than have someone else do it, but again I have to be willing to live with that loss of cash, and thats the part that is killing me right now.

I am leaning towards an option I have not really mentioned yet, that is buying a low mileage used engine and also rebuilding this one. This way I will have something to run wile I am rebuilding this one, and if I fail I will still have a running engine. The thing that really sucks about it is the extra cost.

Smutterbutter

I'm nearing the end of a project almost identical to mehow. Still in the collecting all the pieces phase but doing the rebuild myself. To keep this short, I'll break it down this, and this is just my opinion so take it for what its worth.

If you what to rebuild it to learn, have fun, accomplish something most people never even try, for the love of cars, etc. etc. and are fully prepared to spend the time and spend more $$$ than a mazda rebuild and deal with issues you caused during the rebuild process. Then go for it.

If not, you will save yourself lots of time, money, get back to driving faster, and potentially even have a warranty depending on who you go with so they have to deal with your issues, not you.

At this point after all the tools, parts, upgrades, replacement parts etc. I've bought, I'm well over the cost for a mazda reman engine. Plus Spent hours and hours cleaning parts. But I love every minute of it, and I'm learning a ton about this car and the rotary engine itself.

Don't underestimate the time and money it will take to rebuild yourself, or the fact that its quite possible you'll end up with an engine that performs worse than a mazda reman.

abesRX8

You guys are depressing haha... Thank you for the comments though, it is definitely food for thought and I appreciate the input.

Anyone know the probability of housings being flaked beyond repair, either route I choose to take this is something I need to consider?

Smutterbutter

With 140k miles...highly likely both housings are done for. New housings are ideal obviously but decent used ones can be found if you're patient. Good chance your irons are out of spec with that many miles also.

Between the two engines I've opened myself (100k and 75k miles) only one rotor housing was ok, irons were ok but some at the limit of what the manual says is reusable.