ilamir

So I'm at my wits end with an issue I've been having with my RX8. I'll lay out what's going on and what I've checked already.

So now that the temperature is creeping up I've been having issues after driving my car for a while. No matter what gear I am in, it seems to have a severe loss of power, i.e. I can be going 45 in 6th and floor it with nearly no acceleration and if I downshift to 4th (or even 3rd) while it will accelerate a bit better it is still nowhere near "normal". Add to this that one time recently when this was happening it stalled at a stop and then had a bit of an issue restarting. It took 3 attempts to get it going again. The only other bit of info is that if memory serves it seems to be more frequent when the A/C has been used and I've been caught in traffic (stop-and-go).

My first guess was overheating but the temp gauge hasn't moved (I know this could be faulty but there are no codes thrown either). I did check the coolant level and it was a bit low so I refilled it to the full mark and it's still happening. Oil and filter change have been done recently.

As I said I'm at my wits end. If it was happening all the time it would be far easier to diagnose, plugs, coils, etc. But since the power is fine most of the time, I feel like it has to do with the heat. My thoughts now are heat soak in the coils, or something along those lines. Also, though a longshot, maybe something to do with the transmission fluid needing changed. Thinking here is that the fluid is overheating and then when I try to apply power it's no longer as viscous as it should be and it's slowing down the power transfer.

Any help would be greatly appreciated. If I can't figure this out, then my only option is a stealership...booo.

-Carter

p.s. Sorry for the wall of text, wanted to make sure that I covered it all in the first post.

wcs

iTrader: (2)

How many miles on the odo?

When did u change the coils and plugs last?

Sounds like low compression to me.

The Temperature gauge is useless ... by the time it moves you are already in the danger zone and imminent failure is only minutes away if not seconds
So it's good that you haven't seen it move ... otherwise that would be bad, really bad.

ODDDOOD

iTrader: (3)

With the limited information and my own personal experience, it sounds like a bad fuel pump (or one that is going bad). This seems like a classic signs of failure since it isn't there all the time.

(sidenote: if it was there all the time I would suggest checking the catalytic converter)

Do you notice any difference if the tank is full or near empty? I found going uphill was really tough with a less than full tank. My understanding is that as the tank gets low the pump can get hot and not supply ample fuel to your engine. No extra fuel means no extra power.

Check other threads for fuel-pump failure symptoms and solutions. I chose BHR for my solution.

ilamir

Ok, so 83,635 miles on the odometer.

I've owned the car since it had 34,472 and I've replaced the plugs once since then (yes, probably time for a replace. Getting them today)

As for the coils, I've never changed them out, they may even be the originals. I can get those swapped out as well today. Is it necessary to buy the Mazda OEM or will the ones sold by auto parts stores be ok?

ooobigfire

iTrader: (2)

Before my coils went out it was intermittent. Then one day both the rear housing coils just quit all together.
I used OEM mazda coils. If you have that many miles on original coils then that would be the place to start.

wcs

iTrader: (2)

So before you go buying a bunch of **** you may not need.

Check fuel pressure -- May need to bring it in to a Mechanic for this

Check Compression -- This as well unless you are lucky enough to know someone with a rotary compression tester

Check Catalytic --

Check Coils -- Can buy cheap tester from ...
Check SSV --

Could be lots of things really.

Check engine light on?

ilamir

Cat was replaced about 1 year ago along with the O2 sensor so that's not going to be the issue

Check engine is not on.

Looks like best bet is to take it to a mechanic for diagnosis at this point.

ooobigfire

iTrader: (2)

I didn't mean for him to go out and buy new coils. Just that would be the first thing I would test.. and its quite simple.

ilamir

Per the Mazda Service Manual, can they be tested with a regular multi-meter or do I really need to get the HEI Ignition tester?

wcs

iTrader: (2)

It wasn't direct at you or anyone in general.

I just didn't want him going out and buying a new engine/fuel pump/coils etc without trying to narrow down the issue.

I think all the opinions given are quite possible

I'm hoping for an update after the visit to the mechanic

wcs

iTrader: (2)

According to TeamRX8 ... no they can't

https://www.rx8club.com/series-i-do-yourself-forum-73/diy-testing-all-rx-8-coils-gm-ls2-yukon-coils-sparkplug-wires-222641/

ooobigfire

iTrader: (2)

I just tested mine by taking out the spark plugs and checking for spark. When there was one that didn't have spark I would take the spark plug off a coil that had spark and try it on the coil that didn't spark. If I still didn't get spark after that, then that tells me the coil is bad. If it did spark then that plug was probably bad.

Does that make sense? lol I hope I said that right.

wcs

iTrader: (2)

Huh
Did you know that only the lead coils fire while you crank the motor with the starter?

Or did you remove the plugs while it was idling

edit --- if you have a timing light, you can do the same sort of thing while the car is running

ooobigfire

iTrader: (2)

uhhh whoops.... OP don't listen to me aparently I got very lucky thanks for the tip wcs now I know better.

nycgps

iTrader: (1)

u can't test them because the problem is usually the ignitor part inside that goes out, not the winding, and u can't test ignitor's performance with a multimeter

tza0001

iTrader: (2)

From reading the thread it seems that you never suffered a misfire, and perhaps this is why you did not bother changing plugs, coils, and wires. You should not wait for a misfire though to come. Plugs and coils should be changed every 25,000 to 30,000 miles. Further, the fact that you changed your CAT last year does not rule out the possibility of it to be clogged again. The probabilities in your case increase as your ignition is pretty old.

One more thing I would add in wcs list is to check whether your car has been flashed with MSP16 (applies to early models before 2006). Cars with not the updated flash suffer from power loss after they get driven for a while.

ilamir

Just thought I'd update this to let everyone know what ended up happening. Took it to the dealer for a diagnostic and after getting new plugs and it de-carboned they determined it was still have a loss of power/stalling problem so they contacted Mazda USA. 1 week later and I have a brand new motor, replaced under warranty.

200.mph

iTrader: (9)

the chances that you got a brand new motor are very slim. the warranty almost always replaces the engine with a reman one. gl with it, they have been a crap shoot

wcs

iTrader: (2)

posted test

Posted From RX8Club.com Android App