edblor

A new IAC module did not fix my problem (dealer said the code they pulled pointed towards the IAC), so it is still in the shop.

They did a compression test and MNAO is viewing the results. I may have a new engine in my future!

On the plus side, the Yaris I have as a rental sips gas, so I may just take a trip around Ontario this weekend

Old Rotor

Please give us the history on your car. The service it's had and parts replaced. Type of driving it gets(long commutes, short trip), fuel used(reg or prem), ever flooded, mods installed. Have you ever run any engine de-carbon cleaner to improve compression? You might need this to clean up the carbon buildup from a lot of short drives and not much red lines. Just any thing that you can add.

edblor

The last couple of months are short trips in heavy traffic. The few months before that, medium trips, all highway.

Only mods are a K&N CAI. I flooded it once a year or so ago (the dealer changed the plugs), however the dealer that has it presently has flooded it twice in the last 2 days as it has obvious issues idling!

Other service it has covers the new battery and starter, new engine mounts, never been decarboned though.

I use middle grade gas, I believe ~90 octane.

I have extended warranty, so I am covered should a new engine be put in. The dealer its at is the largest volume RX-8 dealer in Canada, and I do trust they know what they are doing. They have treated me well during my ownership, so I really do not have any reason not to think they are vetting this properly.

Cheers

klanham08

How much would new Engine Mounts cost?

van

iTrader: (2)

I think Engine Mounts are covered under Powertrain Warranty.

UrbanOcho

iTrader: (2)

I had the spark plugs, plug wires, coils, and mounts all replaced last week by the dealer because of rough running "marbles in a can" and now it is doing exactly what you are describing at idle (mine's a stick shift)....so this is very interesting.

I was wondering if they set the idle too low when they did the work last week. If I rev to above 1000 at the stop lights it seems OK but sounds shitty as soon as it drops down to 800/900. After about 10 minutes the idle sustained itself at 1000 and no more issue...it was just the first ten mins of driving.

I am going to try the MAF cleaning. How easy of a job is that??? Anybody??? Are there directions on the DIY forum?

UrbanOcho

iTrader: (2)

I had them done at just above 60K last week (no more warranty???).
I paid $350 at the stealership to have them replace the two mounts.

jiggawha1

Sounds like you are in need of a new motor, I would try the seafoam and if that doesn't help at all then take it to the dealer

fyrstormer

Has anyone here tried cleaning their throttle with carb cleaner and a Scotch-Brite pad? Electronic throttles are particularly susceptible to buildup around the edges of the butterfly valve. I had to scrub the hell out of the throttle on my 1.8t before it would idle properly.

fyrstormer

Most cars need to be run all the way from idle to redline at WOT and part-throttle a couple of times before the fuel trims can be calculated accurately. One more reason to redline it once a day.

klanham08

Are you talking to me when you say that?

Stan-The-Man

Does anyone have any advice on this? Mine does the same thing it hangs around 800 rpm and it vibrates like crazy when it idles in drive and reverse.

van

iTrader: (2)

Need info on your car: year, mileage. Last time your plugs, coils and wires changed. Any warm-start issues?

Stan-The-Man

I have a 2004 automatic with 63,000 miles on it. I just got the coils, spark plugs, and wires changed about a month ago. And i dont have any warm-start issues. I also got a new starter when the coils and all that was replaced. Any ideas?

van

iTrader: (2)

Clean your MAF sensor with electrical contact cleaner, and check your air filter (replace if necessary). While your at it, check for any sign of oil in the air intake.

Stan-The-Man

I just cleaned my MAF sensor with that cleaner and my air filter is clean i checked it when i cleaned the MAF two weekends ago. There were no sign of oil in there.

van

iTrader: (2)

Check the motor mounts for cracks or breakage. If ok, then it could be due to carbon buildup in your engine. I would get a compression test at the dealership just to rule that out.

I also have an '04 RX8 Auto, and my car exhibited the same issues with rough idle at 800 when stopped and in drive. It was especially noticeable with the air conditioning on, and backing up in reverse. But I also had warm start problems which was a sign of low engine compression. Got a compression test ($89), and it failed on the second rotor. I ended up getting my engine replaced under warranty at 153,000 KM's (or 95,000 Miles). Ever since the engine was replaced, I've had no rough idle issues.

Stan-The-Man

I got a compression test around october and they said that everything was fine. So idk. I also noticed that it was especially noticeable with the air conditioning on, and backing up in reverse. When i got the spark plugs and all that fixed they wanted to replace the engine quickly and then a day later were quick to change their mind. How do you check if the motor mounts are cracked?

van

iTrader: (2)

Why did they change their mind on the engine replacement? If it passed the compression test, then your engine is not the issue.

I would report the problem to the dealership, and get them to check the motor mounts. You can check them yourself, but you would have to pull your front wheels off and peel back the splash guard to inspect (mainly the passenger side mount is the affected) - check out this thread HERE. Apparently they have redesigned the mounts with a heat shield and are more resistant to breakage.

Stan-The-Man

Okay so what do the motor mounts actually do? And how would they stop the vibration? Ive always wondered that. And im not quite sure why mazda backed off with changing the engine. We had it all set for them to change it and then the next day they called and said it was the starter instead and totally backed off with changing the engine.

PeteInLongBeach

http://tinyurl.com/6jlz75x

http://www.ehow.com/about_5266976_motor-mounts.html

Stan-The-Man

So does that make sence about why they backed off with the engine?

van

iTrader: (2)

The mounts act as a shock-absorber. Without them, engine vibrations would be amplified through the frame of the car. A cracked mount will also cause excessive vibrations with the exact symptoms you are having (read the thread I pointed out in my last message). The original engine mounts in the '04-05 were prone to cracking on the passenger side due to heat from the exhaust manifold, and so they were revised.

Depends on what you originally brought it in for. If you had starting problems, and replacing the starter solved that, then yes it makes sense. They probably realized the engine passed a compression test, therefore it wasn't the problem.

The reason they replaced my engine was because it failed the compression test. The warm-start issue I was having was a major symptom of low compression. So it made sense to replace mine. I'm not sure what they did to my car, but I reported the engine vibration problem and told them to check the mounts, before they replace the engine. Had no problems after that.

Stan-The-Man

I took it into the shop due to hard starting and a really rough idle. They did the zoom-zoom cleaner, it helped some. And then they replaced the starter. I have no problem starting it now. I forgot to ask them about the mounts, do you know how much that would cost for them to check that?

van

iTrader: (2)

Not sure how much, but it's easy to do and should take less than 30 mins. All they have to do is remove the front wheels and peel back the splash guard to examine. I would stress to them that the rough idle (which is what you originally brought in for before), still isn't fixed. So they really shouldn't charge you for the inspection.