I just bought an 04 RX-8 MT with 40,000 miles. A couple of times when sitting at a stoplight the idle has suddenly dropped to around 500 rpm, surged up to 1200-1300, then drops back to normal. It's only been a coule of times and each time the car has been stopped, in first gear with the clutch depressed. Most of the time it idles smoothly. Any idea what might be going on?

Another question.... I'm taking the car in for service next week. I asked the dealer to check for open recals on my VIN. The service guy told me there was one related to the flooding issue that would take about 45 minutes to do. Some type of reprogramming? Any other recalls I should ask about? Vacuum test? Thanks!

 

The idle should not do that. It could be over due for spark plugs(37K miles). I did my plugs, coils,wires for about $250 with my son in an hour(dealer will charge about $700). It could also be a simple cleaning of the MAF sensor. Or a couple of cans of de-carbon cleaner(Seafoam or BG44K) might improve compression. This is just a start look at the bottom of the page for some more ideas.

 

if your spark plugs, coils, wires are "up to date", gas is good, MAF is clean

then I will start looking at throttle body and ... engine

 

like mentioned above..change plugs/coils if it's been awhile....

 

Thanks! I would guess that the plugs are original. I'll get plugs & coils on order. I've looked through the DIY sections and it looks like a fairly straight forward job.

 

This isn't at the OP........but when the hell did everyone start going 35k+ miles on a set of plugs!
I rarely if ever let them get much over 10k on ANY car I have ever owned!!!!!


OP.....sounds like it's time for coils, plugs, and wires!!!!

 

Can anyone give me a good source for coils & wires other than the dealer? I know I can get plugs online, but haven't found the other parts. Thanks!

 

Well, for piston engine, 30K plugs are ok.

but for Rotary ... 15K the most.


Thats just me tho

www.onlinemazdaparts.com
www.finishlineperformance.com

or just contact BHR.