xMichaelStormx

Hi all. Just got a 2005 Mazda rx8 shinka with 95k miles. It's obvious after reading up on the vehicle before I purchased it that it needs a new engine, or rebuild at least. It's suffering from an extended crank time due to what I think is poor combustion from the engine about about to fail. It's also got a hunting idle, both warm and cold. Along with a rattling rattling from from the exhaust from what might be again the poor combustion. The cat was replaced recently so it's alright. Aftermarket exhaust as well. The last problem besides the cel that just came on is the superb lack of power in in the higher rpms. It feels fine until you go to pass, and then feels like like you are driving a four banger against a race car. Leaving you feeling let down lol. My question to you all is, once this engine goes; should I be looking at a rebuild or an entirely new engine? Keep in mind I'm in Fairbanks Alaska so I'm not sure if I'd have great access to engines being shipped here (not sure how that works, if a shop orders orders it or whatnot; I've never had to get get new one). Just looking for for the best solution, and the RIGHT way to do it. I am purchasing an extended mile mile warranty from usaa before before the engine goes so it will be covered when it does. Anyways, that's about all the info I can think you need to know to help give me some advice about my situation. I'm new to rotaries but I have a general knowledge after doing my research, and am moderately mechanically inclined from projects in in the past. So don't make my head explode but don't be afraid to go in-depth either. Thanks in in advance and can't wait wait to have this rx8 running like a rotary should.

BigCajun

iTrader: (1)

Did you have the CEL scanned? Is it flashing?
If the cat was replaced 'recently' but the problem that ruined the last one wasn't fixed, this one could already be bad.
Usual suspects are bad Coils plugs & wires, recommended change every 30k miles.
The rattling could be a broken up converter, which could give you the symptoms you describe, or chunks of the old converter in your exhaust pipe or muffler.
Drop it, inspect it, if it's bad, gut it. Your engine may be fine.
Read the new owner stickies, mostly all you need to know is there.
Good luck!

Tanro

Sounds like you need a tuneup not an engine.

Engine replacement symptoms are usually more serious.
no start when hot
lack of power across rpm band
smoking warm and cold across rev range
drastic oil use but no leaks
cool burning
overheating

You just have long crank times and lack ofnhigh rpm power which sounds like weak coils. You need to replace coils, plugs, and wires.

04Green

iTrader: (1)

++ ^^

I would start with the Congrats Thread below and, due to your location, likely skip the cooling mods for now (although the foam around the radiator will always help). Clean MAF, ESS, rest ECU, tighten grounds (add star washers), then see what you have. Follow that with coils, plugs and wires. Assume they are almost a decade old unless you have proof otherwise. This is good to do because all of these parts will get reused on a new engine if you go that route.

xMichaelStormx

Turns out cel was just the clutch switch firing for it getting disconnected and reconnected.
As for plugs and etc I have the receipt from previous owner replacing them with a bhr (I think that's the correct annotation?) ignition kit relatively recently. I will however check up on the maf (which has also been replaced recently) and other things like the grounds for the battery.
Anything else I should double check?
And just to make sure what I've read is correct; when I go to shut down the rx8 I should always Rev it to about 4k before shutting it down to clear any carbon right?

Posted From RX8Club.com Android App

04Green

iTrader: (1)

Well,

if you got all that done, I would have the battery checked. Low voltage will make it harder to fire, even with good coils.

Tanro

If you can verify BHR coils have been installed, the wires look pretty new (old wires are going to be dirtier) and you can pull the plugs and they look good, then I would go to the nearest Advance Auto Parts (if you have them in your area, if not check other parts stores) and request a starting and charging systems test.

They will check your battery, starter, and alternator with an electronic device. It will tell you your battery voltage, battery cranking amps, starting time, starting voltage, and alternator output under load and without load.

Battery voltage should be at or just above 12.06 volts. (12v - 12.6v is common)
Cranking amps should be within 25% of original battery rating
Starting voltage should not drop below 9.90v
Alternator voltage should be above 13v both with and without load.

Alternator voltage is probably most important here, as a weak alternator will stuggle to charge the battery and provide enough electricity for the the fuel and ignition systems to function properly.

If you are having voltage issues tighten any grounds, clean your battery terminals // or replace if needed.

ken-x8

Not correct. If the engine is warm (temp gauge in its usual warmed up position) jut turn it off. If it's not warm, then either a) drive it until it's warm then turn it off, or b) let it idle til it's warm, then rev to 3k for 10 seconds, let it return to idle, then turn it off.

Ken

BigCajun

iTrader: (1)

Drop your cat and inspect it to be sure it's OK, and be sure your exhaust is not obstructed.

Ber1n

If its under warranty and you can verify that the engine is below spec ( compression test), I'd get it replaced under warranty. Also, after you get your engine back ( whenever that happens to be), I would perform monthly compression checks to make sure they didn't screw upon rebuild.

Tanro

2005 no warranty unless they upped it 9 or 10 years