Hi Everyone,

Long time reader but first post. Haven't needed to ask anything because the car has been so good to me. I have a 2010 MT R3 which I bought new. It currently has 142k miles on it. I have been following the owner's manual precisely for maintenance. I want to keep this car forever.

It runs perfectly fine to me but given the age, I thought it was time to have a compression test done. My numbers are: Front Rotor, 80 PSI / 83 PSI / 85 PS and Rear Rotor: 80 PSI / 80 PSI / 80 PSI. When I asked about RPM I was told "a little over 200". My understanding from the compression test chart is that this translates to "6.5-6.9: Officially failing. The engine doesn't have all that long to 'live'. Compression loss is accelerating due to blow-by." Both the person doing this test and the Mazda dealership say it's time for a new motor/rebuild but hard to justify given the car is running so well. Mazda does have a new engine available for me to order which is tempting because maybe my engine will fail soon and maybe they will discontinue making them.

Options are:
1) Keep driving until it fails and then decide (difficult because with other options I can plan better, but possible)
2) Get new engine from Mazda including clutch $13,000 CAD + Tax
3) Engine rebuild, around $6000 CAD

Any thoughts/advice would be appreciated. Thank you!

 

Jeez. Not too long ago a new engine from Mazda was 6k.
​​​​​​Don't rebuild your engine in any case, depending on what's included in the 6k, putting new seals in tired old housing is not a recipe for longevity. I'm not sure about Toronto rebuilders but usually thr best option is to buy a rebuilt engine made from known good parts from a reputable rebuilder. Derwin Tuning in Montreal might be the closest. It shouldn't cost much more than thr 6k you were quoted.

Obviously a fresh Mazda engine installed and all that is ideal but for 13k+tax is a solid down payment on many cars or other important things.

If you're not having actual symptoms I wouldn't rush into it. Realistically those compression numbers are borderline. I got something similar in 2014 and the same engine later showed better compression and is still in spec to this day. Why did it show low that one day? Who knows. But you have time. You could consider premixing to give it the best chance and help seal any gaps that are forming on the seals' friction surface.

 

Thanks for taking the time to respond! This is so helpful. An interesting point about higher compression numbers later, I have never heard of that. Sounds like it's time for me to learn about premixing...

 

You can maybe drive it another 2 years.
​​It's what happened to me.

You can source a new engine from Mazda, but I'd recommend finding a rotary specialist to do the labor.

Last year I paid $6000 USD for a new engine from Pineapple Racing, once removed.
Paid a rotary rebuilder 3 hours south of me $800 for labor, less the old engine for a 'core'.

I also paid him for a whole bunch of other work 20 year old RX8s need.

Ended up around $10K USD.

Mine flunked when I had it tested while it was getting the airbag recall.
It wasn't giving me any problems, I was just curious.

I was shocked when they told me it failed.
That's when I started the Rebuilders Thread.

I recommend reading it, along with the linked threads.

https://www.rx8club.com/series-i-tec...ilders-265177/


https://www.rx8club.com/rx-8-discuss...5/#post4987680

 

Derwin Performance Rotary Engine Specialists in Canada

 

It's not "failing" if it's running. With very good maintenance, it can take you into the future.
​​​Don't abuse it, the redline a day nonsense and such.

 

Thanks for this info and for sharing your story. Sucks that the shippers did that to your engine. Saw the pics of the box, wow! I think you are right about 1-2 years left from all my reading. So, knowing what you know now, you would get a rotary specialist to do the work, but would you say go with a new engine if I can get one or have them rebuild and order the parts as needed? Let's say price is not an issue, only engine/car longevity.

 

Thanks for this info and for the links. I read through your story. Wow, that's terrible about the shipment! Those pictures of the box you posted look terrible So, knowing what you know now, you would get your work done with a rotary specialist, but would you have them get a new engine if possible or rebuild and order parts as needed? Let's say cost was not an issue and you wanted to maximize engine/car longevity.

 

Thanks for this info and for the links. I read through your story. Wow, that's terrible about the shipment! Those pictures of the box you posted look terrible So, knowing what you know now, you would get your work done with a rotary specialist, but would you have them get a new engine if possible or rebuild and order parts as needed? Let's say cost was not an issue and you wanted to maximize engine/car longevity.

 

Thanks for this info and for the links. I read through your story. Wow, that's terrible about the shipment! Those pictures of the box you posted look terrible So, knowing what you know now, you would get your work done with a rotary specialist, but would you have them get a new engine if possible or rebuild and order parts as needed? Let's say cost was not an issue and you wanted to maximize engine/car longevity.

 

Just wanted to pop back and say thank you to @BigCajun , @Loki and @peloponisios . Based on your advice, didn't do a rebuild or replace the engine and it's still going strong! Currently at 149k miles on original engine