vsvartak136@gmail.com

Hi,
I am new to this club. I have a 2005 RX8 which I've had for 2 years. I have used it for 24k miles during which I changed the oil 3 times(I am guilty of not changing it at recommended 3000 miles interval).
So, now, I am trying to sell it but lately it has been having hot start issues. It does not start when tried cranking after it's been warmed up. It start perfectly from cold though. So, I had the compression test conducted on it and got back the following results:
Rotor 1: 86 psi, 83 psi, 85 psi
Rotor 2: 84 psi, 85 psi, 86 psi @ 202 RPM at Elevation 650

When normalized to sea level and @ 250 RPM, the results are:
Rotor 1: 102.4 psi, 98.83 psi, 101.21 psi
Rotor 2: 100.02 psi, 98.83 psi, 102.4 psi
which when compared to Mazda specs for the Renesis motor (04-11) are still higher than Minimum acceptable.

What I'm curious to know is how long do you (esp. more knowledgeable & experienced) guys think I have before the engine totally wears out and would not start at all?
Is there a way I can add some more life to the engine say by installing a faster starter motor/Spark Plugs/ Cleanse the engine?
Also, lastly, what do you make of the numbers that I got back from the compression test?

I'd really appreciate your advice/suggestions on this topic, as I am in a predicament of making a decision whether to put a new faster starter motor or replace the engine altogether.

Thanks!

Jedi54

iTrader: (7)

never fear, Jedi is here!

first off, you really should be changing the oil on this car as recommended since by design the motor burns oil to lubricate the seals, the last thing you want is to be running low or having really old oil in there.
That said, nothing you can do about that now, just try to be better about it in the future.

as for your compression figures, it's tough to say really. My original motor on my 2005 was below the minnimum for quite some time and still ran GREAT; never had an issue starting up and put down more power on the dyno than most other NA RX-8's I've seen (and believe me, I've dyno'd tons of RX8's over the years)
Will it go out on you some day? yes.
when?
no clue really. Could have a couple years left in her, could be gone next month.

it sounds to me like your starter is the old design so that might be something you want to look at to help it start up but if it's continuing to have 'hot start' issues, that could be a problem.
Does the car still have the stock catalytic converter on it?
how old are the plugs?
ignition coils been replaced?

since you're still above the minimum, I would advise against replacing the motor and I'd focus on things to help it keep running.

side note: isn't the S2 starter compatible with the '05?

vsvartak136@gmail.com

Jedi 54,
Thanks a lot for your reply.
The car still has the stock catalytic converter on it? I ma just curious why you ask. How would a catalytic converter affect the apex seals? Unburnt fuel I am guessing.
Both Plugs and coils were replaced at 33k by the previous owner, around 2.5 years ago.

And, I'm not sure about the S2 starter's compatibility. I was thinking of putting a faster, 2KW starter on it, changing the spark plugs, changing the oil and cleaning the engine with Mazda Zoom power cleaner.

Any suggestions on the same? Also, if you think these are good ideas to keep it running for some time, what order would you suggest to go about completing above tasks?

Also, I'm thinking of making the above changes and selling the car. Not sure about it yet though.

Thanks,
Vartak

MiRe

The stock cat has some known issues with becoming clogged, which can cause issues with startup and general performance. The best way to check is to take the car for a hard drive and then look under the car to see if the cat is glowing/hot.

Besides that, it sounds like replacing your coils/wires/plugs might be in order. It's recommended to do every 30k miles.

The starter is definitely a consideration considering it's a 2005. You might consider trying a different battery or getting the battery tested before going so far as replacing the starter. It could potentially be a problem and it's certainly easier to test.

If you do use Zoom cleaner, make sure you look around the forum and find the proper way to use it. It's not just pouring it in the tank. You should definitely work on keeping on top of the oil changes as well if you decide to keep it. That's important in any engine, but even more so with the oil being used as an injected lubricant.

vsvartak136@gmail.com

Mire,
Thanks a lot for your reply.
I changed the battery recently. It was nearing it's end. Also, as soon as the warm start issue started to show symptoms, I checked the newly installed battery and found it to be completely fine.
I missed out on providing one important info. Whenever I try warm starting the car by jumping the battery, it starts pretty normally. Which is why I'm thinking of putting in a new, faster starter.

Also, I'll check the Cat as you suggested.
Reg. the Zoom cleaner, can I do it myself at home. Also, should I do it before replacing the plugs. I read somewhere that cleansing process needs to be followed up with plug replacement.

Thanks,
Vartak

CelestialGryphon

iTrader: (1)

Pretty much anytime you burn out built up carbon you want to change oil, more-so on these cars than anything else, and plugs for sure as well.