2004 MT w a 05 shinka motor

So I’m driving really getting on it to pass some cars when suddenly engine power goes to one rotor. Pull over let off gas dies. Code P0302 rear rotor. Get it home go thru check list, simple things first. I bought a comp tester find out I have 0 compression in 2nd rotor. So I drop the oil pan to check for metal and nothing. Didn't hear any sounds of scraping metal in housing. So question is can my apex seal get stuck in the middle of WOT? I’m soaking it right now in b12 to loosen them hopefully and gonna try the other things I found on the forum. But any opinion on why sudden power loss? And would you find metal in oil pan if it were seals? Thank you for you time.

 

This isn't a piston engine that when you loose a cylinder you get metal I'm the oil. Failed seals don't end up in the oil

The only failure you will see metal in the oil is a bearing

 

For series 1 (2004-2008) Rx8's there were only 2 engines in reality. [In United States Markets] There were the 6 ports (2004-2008 MT cars and 2006-2008 AT cars), and there were the 4 ports (2004-2005 AT cars).

Trims like Touring, Grand Touring, Shinka, they featured ZERO differences between the engines (I wanted to clear that up for current and future readers since the misconception there is seems to be spreading like plague).

All Series 2 Rx8's had slightly different Renesis engines (revised OMP design with 3rd injector nozzle per housing, different front cover relocating oil filter to the cover, increased oil pressure, and more minor updates). HOWEVER, the same rule applied for the Series 2 Rx8's where the various trim levels including the iconic R3 all have the same exact Series 2 Renesis engine, which are all 6 port for both the automatic and manual transmissions.


All of that said... your motor is probably screwed. 0 compression means likely catastrophic seal failure and it probably damaged other components on its way out of this world.

If you can't afford a Mazda reman or rebuild, good luck with the rolling chassis/part out.

Sorry for the crap news, just rather not feed you b.s and get your hopes up. Try what you can but plan for the worst.

 

Thank you. I just put the basic of the car description. I knew about the trims and diff yr motor but thought I should just put it on. I’m on the 3rd motor now prob 4th. Just didn’t know if failed seals end up in the pan. But can seals get stuck at WOT?

 

If you're on your 3rd motor, something is killing those motors. What kind of maintenance do you follow?

You have 0 compression on all faces of rotor 2? 1 seal could get stuck maybe, they can't all get stuck at the same time.

 

It's when the most stress is on the engine.

There could have been a pre-ignition event that broke an apex seal. There are other failure modes that are possible but it's all speculation until somebody opens the engine up.
If it was one broken apex seal, you should have two rotor faces at 0 psi and one at >0 unless the one broken apex seal spend some time whizzing around in the combustion chamber destroying the irons and/or rotor housing.
A pre-ignition event could destroy two seals simultaneously in which case you have even more metal whizzing around destroying things.

None of this will end up in the pan. If you don't want to pull the engine apart to find out, get yourself a cheap borescope or endoscope off of Amazon and scope it out while turning the crank by hand.

From a price vs new parts content perspective, your best value is in a Mazda reman motor. If you know how to search, you can find one in the US for ~$2900 + tax + freight + $1000 core. Expect return freight on the core to be ~$250 if you bought from a dealer less than 4 states away. Just google this part number: N3H3-02-200R-V0 (try it with and without quotes for slightly different results). Any seller with a "Revolution Parts" logo on the bottom of the page (see here) is an actual Mazda dealer using the Revolution Parts e-commerce system to increase their sales reach.

If you're like me, you'll find one only a few hours away that will let you do a local pickup. This might cost more in tax but you'll save on freight costs shipping the motor to you and then shipping your old one back.

If you like to roll the dice, head off to eBay and pay $1000 less for a motor that DEFINITELY won't last nearly as long, DEFINITELY won't have as good compression, and DEFINITELY won't make as much power as a Mazda reman.

You can also pay a lot more to Mazmart, Banzai, Pineapple, Drummond, Rotary Resurrection (I think they'll do this) and have them start with a Mazda reman and upgrade the crap out of it.

Do not bother to bridgeport your new motor. As TeamRX8 is famous for saying (paraphrase): Bridgeporting a Renesis is like digging a big hole in the ground, dumping $6000 in, pouring gasoline on top and then lighting it on fire.

You should also go over everything attached to the engine with a fine toothed comb to make sure this failure wasn't a symptom of a different problem!!! There's no point in plunking down $2000+ only to have it fail again because there was a bad solenoid, an injector was clogged, or the ignition components were failing.

Budget an extra $1000 to do this right. 99% chance it won't cost even $200 but you never know and it's better to prepare for the worst and have money left over.
Pull vacuum on all of the solenoids and oil injectors. Purchase a $20 HEI coil tester and test your coils. Send your fuel injectors off to someplace like Witchhunter Performance to be cleaned and flow tested. Make sure your fuel pump is holding at least 54 psi. Pull your oil coolers and lines, check for rust, remediate as necessary. Clean up all of the chassis grounds in the engine bay and use dielectric grease when re-attaching. It may also be worthwhile to upgrade the grounding strap connecting the LIM to the chassis under the air pump. Check the foam around the radiator and make sure it's present and in good condition.

He said it has an 05 Shinka motor which makes me think that he put a used motor in it after one of them failed. No idea what kind of condition that motor was in when he installed it.

 

None of this makes much sense. You cant have 0 compression on all 3 rotor faces unless something really catastrophic happens. In my experience, you only get no reading from the tester if the engine is flooded. Was there any oil on the tester after you attempted the compression check?

That code is a misfire and usually doesnt lead to instant destruction of the engine. I suspect this happened due to an issue with the fuel or your ignition system. Try to run the test again after deflooding the engine and getting it running. You should be getting numbers.

 

A shattered seal will usually go for a spin or 80 around your engine, destroying everything in its path. Not unheard of.
You should find metal dust on the lead spark plugs if that happened, but no dust doesn't mean it didn't happen.

 

I took the T spark plugs out and rotated the motor to inspect each apex seal. Found one was absolutely gone and had scoring marks on the rotar faced. It was a used motor out of a fire accident. As for maintenance I always change oil at 2.5-3k always premix and make sure to clear the carbon often. So time for a rebuild or reman. But thank so much everyone. I love the Rotary community and have had a 86-7 and this 04 for 10 plus years and am still learning lots of stuff. I do everything myself and did the last swap. But again thanks so much guys.

 

Thank you, found the problem. Missing apex seal. Ima look into a reman or a rebuild kit. Either or I love rotaries and can’t wait to install or fix my car. Super bummed it failed but it’s car life and **** happens. Ima look for a reman close to Baja California I’m sure I’ll find one.

 

Go with the reman. Sounds like internal engine damage rendering a rebuild nearly impossible without replacing housings/rotors.

 

I have extra housings and rotors, always prepared just need apex seal kit so I’m not using the old ones.

 

And side seals, and coolant seals, and bearings...
Don't do a half rebuild, unless you want to do it again in 6 months.

 

If you are staying NA.. stay with OEM OEM apex seals....

 

Nah, man, gotta go with those $3,000 Iannetti ceramic apex seals!

 

In that case take the engine apart first before you order the kit. This way you'll know which kit and extra parts to order.

 

People think replacing apex seals is no more difficult than replacing a head gasket, LOL.

Anyway, just get a reman. You need a lot of parts, money and time to make an engine on your own, and in the end, you'd be lucky if you did it all right.

 

Exactly! It's a complete removal and disassembly of the entire engine. Not to mention the engine is buried way back in there requiring you to catalogue and organize nearly every part of the engine. It's an extremely involved process.