RX 8 Rough Idle
 

Say, wanted to get some ideas. I've had several problems with my 8 of late.

Main one now is that when I start up, it idles rough.. like it bucks sometimes. I had new plugs put in about six months ago. I'm getting error codes P0037 and p0301. (I've checked the strings on the codes..) I've also gotten one for an o2 sensor from a while back, but was told it wouldn't affect idle, etc.

When it starts up, if I have the AC on it seems to have the most trouble. Idling rough, etc.

Also, when it gets real hot it loses power some. I've noticed this lately with the heat and on those long trips it happens some. When she's cold, and sometimes hot, she's snappy and fine.

And, sometimes it will rev to 2000 rpm, hang out there for a while, then get back to normal. I've also had days where it's fine, and lately its been harder..seems to be effected by the heat.

Also, for the last couple years, when I go on a long trip at speeds of about 70, when I get off the freeway it sometimes dies or cant find the idle too. That's been going on for a while (couple years like I said).

I put in a new air filter, no real change.

Thoughts?

Thanks in advance...

front O2 sensor, coils, wires, and engine compression. Probably your cat too by now if you have been driving with misfires.

P0037 - Rear HO2S heater control circuit low
P0301 - Front rotor misfire detected

Did you get a front or a rear o2 sensor?

Maybe the catalytic is failing?
Or it could be the Rear O2

When is the last time the Coils where changed?

Clean the ESS and do 20 brake stomp reset.
Clean Maf
Check motor mounts, maybe there are causing rough idle?

Low compression?

Darn it
I got beat by the moderator again.
lol

THanks guys! Just cleaned the MAF and the CEL code for the H02 sensor says bank 1 sector 2. Am going to take it in I think, have it checked if
the MAF doesn't do the trick. I'll let you know...

Eh, wasn't the MAF :)

Well, found out I have coolant in the #1 rotar. Questions, are there options other than a completely new motor? I'm being told that if they did a rebuild, and the two places I know don't, it would be about the same.

Also, she's got some miles on her. so pondering if other things will go as well. Thoughts?

Thanks all!

Yes, rebuild or replace is the only pair of options for a coolant seal failure. $2k-$3k is in the range you can expect, though you could get lower. + labor of course, if you can't do the pull/install yourself.

Coolant seal failure is common with a cooling system failure, so you probably have a failing thermostat, clogged radiator or lines, etc...

Yea, I'm being quoted $4400 (including labor) for the rebuilt one, I think its from mazda. $2525 for the motor and 1500 for labor and 375 for parts....

Yeah, you can do better than that. Depending on where you are in the country, you can do significantly better than that.

list price on the engine is $2000, although there is a $120 gasket set in the box too.

Im up in seattle, wa. Ideas on places up here? It's not something I can do myself, so would need to take it somewhere.

Thanks