2004 rx8 will not start when warm
 

I've been constantly researching this topic trying to find answers, and have yet to find the solution. I have 134k miles on this motor. 6 speed. Here recently my car has been giving me hell when trying to start when warm. I normally have to wait 10-15 minutes for it to cool, then it will start no problem. Ive replaced the coils, plugs, and plug wires with all OEM products. I've replaced my battery terminals with marine terminals. I've declogged my cat. I have even recently replaced my radiator/flushed the coolant. That has nothing to do with it, but the oh so nice factory radiator overflow outlet snapped off, so I replaced it with a mishimoto. I haven't had a compression test done yet, but I refuse to believe that this motor is about to take a shit. She still runs well, idles well, and has power. I have about 4 weeks to figure this out before I deploy for the navy, so please help me guys! I've been pulling my hair out trying to get it running properly before I deploy.

Do a compression test.

It's the only way you will know.

A compression test would be a very good idea, but your starter could also just be too slow to start it when it's hot, although this would more than likely mean you have subpar compression as well. A failing slow '04 starter should still start a warm engine if it has good compression, it just takes longer than normal. You may be able to replace the starter and fix things temporarily. What year is your car?

Guess I'll have to get one scheduled. It will be a serious bummer if my motor is going bad. I heard rebuilds are not cheap at all. And to answer your question, it's a 2004. Just called the Mazda dealer from where I bought the vehicle. They want to charge me $90 for a compression test. Does that sound about right?

That is cheap, just make sure they give you the results and if they tell you they can't, they are lying.

Yeah, it's actually a bargain compared to here. My dealer charges $180 for a compression test. Be sure to get the actual compression numbers that your car scores instead of just pass/fail so you can post them here.

Yeah..Since its an '04 you may have a slow starter.

That's insane. Yeah, I definitely will ask for them. I appreciate the info guys. I read into the starter ordeal, and that upgraded starter (N3Z1) I believe, is pretty rare to find. I saw that Mazmart is stocking them again, for about $375. This Mazda treated me real well the past few years, but she's digging a hole in my pocket now.

Hit up Car-Part.com--Used Auto Parts Market. I had the same issue as you (not quite as bad though) and I went here. Just search for a starter from a 2006-2008, call them up, and make sure it is good. I spent $60 on a 2006 starter and it did wonders for my 8.

you shure its on its first engine?

I had an 04 come into my shop same exact problem with yours did a compression check and failed replaced his engine with a used one cuz customer couldn't afford a reman one and fixed his problemdriving around pperfectly good now for about 6 months now highly recommend compresaion check

You can also buy a starter from Advance Auto. They sell a faster starter. Just say your car is an '08 to get a faster (2kw) starter for ~$150

I purchased it directly from my local Mazda dealer with about 73k on it about 3 years ago. There was one owner of it before me, an older lady apparently. I couldn't tell you if it's on its first motor or not. They surely didn't tell me if it had been replaced. I wouldn't put it past them either. I'm going to start with this compression test. I was watching some clips of people doing the compression test themselves on a conventional tester. From what I understand, you must unplug the eccentric shaft sensor plug first, then continue with the compression test.

Thats how it works, but unfortunately, conventional testers don't give you an accurate reading.

Bummer. Is it even worth trying? I just had my car put on a scanner beings my CEL was on. Only codes thrown were for my Emissions, since I honed my cat out. I honed that out since it was on the list of things that may cause issues during hot start. Plus I did flood the car awhile back, so I'm sure the cat wasn't in the best of shape.

There's really no point. You have to have a rotary compression tester for the readings to even be remotely useful. You'll just have to take it to Mazda to get it done

Standard compression testers are not very accurate for rotaries as its very dependent on RPM. But you are correct about unplugging the ESS

The dealer will also give you the RPM your starter is at when performing the test, which is calculated on the Factory Compression tester. You will need a new starter below 200, 200-240 is weak and a good starter is 240+ RPM..

So get the compression test done before replacing the starter and go from there! If you fail with high numbers and your RPM is 240+ they will likely recommend a de-carb

the upgraded starter is really easy to find, its finding the $$ that is the hard part.

N3Z1 isn't the current part number either, although if you use it, you will get the right part