RX-8 Symptoms and a Dealer visit -- Any suggestions?
 

My 2011 RX-8 has been having an issue with rough starting for the past several months. It starts up quickly, however it immediately misfires and sometimes sounds like it is only running on a single rotor (very rough idle). At the same time, there is an odd sweet odor around and inside the vehicle.

After running for a minute or so, it will clear up and operate normally at all RPMs and load factors. If I shut it off, it will start up with no issues and runs smooth.

In operation, I occasionally observe a gurgling sound from the glovebox area (heater core perhaps). I have also had to add a little bit of coolant as the coolant light came on a time or two.

I gave these details to the dealer and they told me that they could find no leaks. They did however pull the plugs and found that they were rusty. They recommended replacing the plugs and wires.

Opinions?

Did the dealer pressure test the cooling system? Do you see white smoke out of the exhaust on the cold starts?

Is your temp gauge doing anything weird?

Now that I think about it, they didn't specifically say that the pressure tested it. I do assume that is the procedure they used though as I don't know how else they would have arrived at the conclusion that it "isn't leaking".

Also, I do not notice white smoke. That is sort of odd isn't it?

No, not at all. Also, the temps from my OBD scanner seem normal as well.

They could have just done a visual inspection of coolant hoses/radiator/coolant bottle. Don't underestimate dealer laziness. Do you have pictures of the plugs?

I am not sure the size of coolant seal leak you need before you see appreciable white smoke. Maybe some more experienced members can chime in...

Do you ever see any of the coolant (since youa re having to add it) on the ground under the car?

Since I don't see it on the bill, that is a good point. I would really hope that they wouldn't do that in this case. Too bad that I didn't think to ask specifically.


No, I have never noticed any. Although the amount would have to be really small, I think.

Also, have the misfires been bad enough for it to throw CELs?

Yes, it reads as a misfire on Cylinder 1.

I take it that was one of the rusted plugs?

Someone in another thread from a while back had similar issues.. I only captured a spall part of it though...


https://cimg8.ibsrv.net/gimg/www.rx8...17c45add2c.png

And here's the link to that thread in case you want to read the whole thing (ignore that last part of the title, is explained in the thread);

https://www.rx8club.com/series-i-tec...-188047/page2/

The dealer didn't say and I am not entirely sure how to confirm. Which rotor is "cylinder 1"?

I saw that thread earlier. Mine starts up much more easily and I do not have white smoke. That could just be an indication that the severity of mine isn't as high, though. The rest of the symptoms seem to fit.

I'm not sure how to convince the dealer, though.

Cylinder 1 is the front rotor. Changing the plugs and wires is definitely a good idea if they haven't been changed in a while. "Rusty" is a strange description, but I guess the brown gasoline deposits could look like rust.

I'm not sure what's to convince: if you lost coolant and they found no leaks, then this merits a pressure test to eliminate (or detect) internal leaks. That's literally the next logical step.

I agree, although I'm not sure that I'd have them do it. I am also really hesitant to do it at all when I'm pretty sure the engine is leaking coolant internally.

Yes, I need to find out why they didn't do a pressure test today actually. It seems logical to me as well.

Your engine is still under warranty, so if it needs be replaced, make sure it gets fresh ignition components. Maybe not at the dealer, as spark plugs and coils are way cheaper in the aftermarket.

That's basically what I am planning to do. It doesn't seem like the plugs and coils would be hard to do myself.

I did that ^
Had my engine replaced by the dealership, let them put the coils and wires back on, then changed them myself after I got it home.

I think if it's leaking coolant/water internally, that can rust the plugs a bit?

That is exactly what I think.