Start and run issues...
 

Hello, I am a proud owner of a bone stock 2004 Mazda Rx8 (116k miles). I have owned the car for 5,000 miles and it's obvious the previous owner didn't do his research, I ran it right but issues came...
Just had my vehicle inspected by a Mazda Dealer in Dayton. They said that my compression is bad, and they also replaced my battery.
I have always had issues with starting the car after I drive it for a bit (i.e stopping at speedway and it won't start for 15 minutes) but last night I was driving and my engine light started flickering and RPMs starting dropping, I couldn't accelerate pretty much at all, I got to a light and my car died, I checked it over:
All fuses good
Oil level good
Gas - half tank
No visible issues
I left it at a speedway and came back in the morning, kept cranking but no start, I pumped the gas and managed to start it, drove it 500 feet and it died on its own, now I have no idea what I can do...

A flashing CEL is ALWAYS a Misfire.
https://www.rx8club.com/series-i-tro...t-here-222584/

It seems you should also read this.
https://www.rx8club.com/new-member-f...t-here-202454/

Can you hear your fuel pump prime?

When Mazda checked your compression, what were the results? They should have supplied you with #'s for each rotor face and an RPM.

Like this
Rotor 1: 5.6, 5.6, 5.5
Rotor 2: 5.6, 5.5, 5.5
RPM 250

However, if Mazda has confirmed low compression your only options are really purchasing a Reman, finding someone to do a rebuild, rebuilding it yourself, selling it or parting it out...

Welcome to the forum btw.


Travis

Now where have I read this before?

All of my compression numbers were below 7, I don't have the sheet now, and I don't remember it saying RPMs when I looked it over.
Also, what would it sound like when the fuel pump primes

so your motor is toast. you've lost all compression on at least one rotor and likely ate a seal or two.

the blinking CEL was misfires as a result of gas sloshing around the housing rather than you getting a good compression stroke.

If it's compression then how would I be able to restart it again? I was able to, it drives for a short time but then cuts out.

Metal expands at different rates.

The housings expand more than the rotors and the apex seals can no longer maintain the seal.

I.e. cold motor = better compression.
hot motor= less

Mazda has already informed you of low compression scores.. sorry but it is what it is.

Travis

Compression loss isn't an "on off" switch.

When the engine heats up, the rotor housings expand away from the rotors faster than the rotors expand to keep up with them. A rotary will ALWAYS have better compression when cold than when hot, even when compression is good. Just as seals wear down, they have a harder and harder time bridging the gap that is created when the housings expand away. We are only talking thousands of an inch, but, yeah, it does matter quite a lot.

Starting fine when cold but having trouble starting, or keeping it alive, when hot is classic rotary low compression.

Why can't I keep it in the on mode of that switch... :( a new motor will cost me 4,500 (including labor) and my car is valued at 5,000 it's not even worth it, probably should just part it out now shouldn't i?

Parting out a car takes a lot of patience and diligent work, but you could net the most amount of money that way. Otherwise, it is likely you could sell it as-is for $1,500-$2,500, depending on the condition of the rest of the car. A bit less money, but over and done with in one shot.

I assume you have an automatic transmission in it? That would specify a 4-port, which is the higher $4,500 motor cost (due to be less desirable and thus far far rarer).

No, 6 speed manual. (Ew automatic lol). But that's just a quote from a Mazda Dealer. I could buy the engine for 2,000 but I do not have the rotary knowledge to swap engines myself

$4,500 all-in from a dealer is ... one of the lowest prices I've heard.

$2,000 for a motor is also highly unlikely. The list price for a 6-port used to be $2,001, but that was increased to $3,300 about 2 years ago I think. That's the cheapest you can get a new reman. The $2,000 was probably a rough idea from a guy that doesn't know about the price increase and is remembering the old price.

it's A Mazda dealer in Dayton Ohio, the guy is a rotor head and looked up a quote for it, he stated it was 2500 for the motor and 2000 for labor, but I also have a 10% off with them, so really it's just over 4 grand, but still, when working I would only be making a grand if I sold it with a new motor.

Yup, if you are selling anyway, it is usually net-cheaper to just sell as is than trying to fix it first. You will always lose some of the repair investment.

Gotta love losing money. Sigh. Thanks for the help, I appreciate it.

Yeah, it sucks. We see it all the time here. New owners that buy someone else's problem. Dead engine'ed 8s are far more common on dealer lots than they are in garages. We constantly recommend to new owners to get that compression test first. Losing even several hundred on testing several is better than thousands buying a bad one.

I was hunting for a replacement 8 for a while, and 3 of the 4 RX-8s I had compression tested were outright failures, and the 4th was only barely passing.