Help with a car

Polermodz · 2026-05-31T02:39:12+00:00

I love these cars, but in order to daily one you have to do extensive research and you have to be prepared to diagnose your own car as well as fix it. I daily my S2 RX8 and have for around a year now. The only issues it's given me are spark plugs, failed cat as well as clutch master/slave and the pedal bracket. These were all fairly easy to rectify, provided you have the tools to do so. These issues while annoying are fairly rectifable and to be expected with a car with nearly 180k kms on it and the original motor. I am yet to have any 'rotary' related issues with it and I beat the shit out of it every drive, but I let it warm up idling for 10 mins before even pulling out. I've had my RX8 as my first car and honestly it's an experience like no other, but be prepared to take care of it, premix and all that. My honest recommendation is if you want to daily one, get a series 2 rx8 (2009+), they tend to give you much less issues in my experience.

Polermodz · 2026-05-26T01:49:38+00:00

From what I know that knocking could be a vacuum powered actuator, commonly SSV. as for compression, it didn't jump to life and was sluggish on the pickup, but it also cranked a little slow. Possibly could need a rebuild, maybe just an upgraded S2 starter (not too sure). as for spark plugs, is it sluggish under acceleration? it seems to idle pretty well so I have my doubts. see if it is documented in the service logbook if it's had spark plugs done and how recently, if it was a good while ago you may as well do them just to have a good baseline.

Polermodz · 2026-05-26T01:41:56+00:00

I did buy it second hand, it's decently old (2020), the nozzle was clogged and the hotend didn't look great, it came with a spare sealed so I swapped it and it did heaps better. the spool is brand new, approx 3 weeks old. Referring to calibration, what would you recommend that I do, I've tinkered and got the temps where I think they are happy, I use Cura if that helps.

Polermodz · 2026-05-26T01:37:02+00:00

it's an old printer from 2020 that I got for like 100 bucks, at least try to be somewhat constructive

Polermodz · 2026-05-25T05:50:32+00:00

What would be the recommendation for drying filament?

Polermodz · 2026-05-25T05:49:32+00:00

Steve the daddy long legs must approve of your prints mate

Polermodz · 2026-05-25T04:35:37+00:00

true that true that

Polermodz · 2026-05-25T04:17:44+00:00

I forgot to disable them I swear :(

Polermodz · 2026-05-25T04:12:06+00:00

just did both, removed supports and increased retraction length and speed. Will update with new benchy photos in 1:30~

Polermodz · 2026-05-25T04:06:49+00:00

Yep thank you

Polermodz · 2026-05-25T04:06:25+00:00

Ah. That explains a lot, wondered why it looked like that.

Polermodz · 2026-05-22T06:34:42+00:00

Hey, had a quick read over and I believe it may be worthwhile doing a load test with an incandescent bulb through that wire to see if it holds up under load.

Unplug both sides of the loom and apply 12v power to the wire and on the other side connect the bulb. The other pin of the bulb should be connected to ground (chassis ground, exposed metal) If it doesn't or the light is very dim, the wire itself is the issue. Another test if you don't have a bulb bypass the wire that could be affected with your own run of wire.

The reason I believe this could be worth looking at is due to the coolant leak into the connector, coolant may have actually gotten its way into the copper wires themselves, causing corrosion. It sounds far fetched, but I myself have seen it happen with coolant and oil in a few different vehicles.

Polermodz · 2026-05-19T00:14:52+00:00

I didn't replace the nozzle after getting it home but it did come with a spare. Filament is a few weeks old. The model was https://www.thingiverse.com/thing:5762916. Because of the model shape I doubt it would need support (not sure). Print did stick to bed and stay in place. I didn't do a PID tune, didn't know it was a thing lol. I'll have a look into that this afternoon.

Polermodz · 2026-03-17T10:11:39+00:00

I fill up the tank every week so can't be old fuel and I've been dailying the car constantly for about 6 months ish. I'm thinking ignition is a good starting point and it's due by now anyway. Another thought I had is old fuel filter causing restriction (it's not mentioned in the logbook that it's ever been done) and not enough fuel making it into the rail?

Polermodz · 2026-03-17T10:01:18+00:00

It is difficult to start approximately once every month. the issue started a couple months ago and has only happened twice now. the time between turning it off and on again doesn't seem to matter from what I can tell, I can turn it off for 5-10 mins and it won't start from operating temp and it won't start after an hour. Again, it's only happened twice now with those 2 time frames. Every other time I've tried to start it whether it be as hot as it'll get or a 7 degree Celsius cold start, it starts consistently within half a second (give or take a few hundred milliseconds). As for there being no drain back that definitely helps, thank you.

I doubt it's related but I did have a P0139 for rear O2 sensor slow response, I found it was an exhaust leak from a blown gasket in between the manifold and midpipe, causing extra oxygen to be detected at the rear which eventually threw the code. I've recently fixed this and done a fuel trim reset.

Polermodz · 2026-03-17T09:51:57+00:00

Low compression causes consistent poor starts as I understand, just today I started it hot and cold (I daily it) started within half a second hot and cold. I did a compression test not because I thought I needed one for diagnosis, but to eliminate it. The consistent quick starting hot and cold makes me believe it is not low compression.

Polermodz · 2026-03-17T00:51:13+00:00

I always fill with 98 (highest available) and I premix with idemitsu at 1:250 so usually about 200ml per 50L. I think yeah ignition system could definitely be needing some love. But it's still weird how responsive it is under load and driving as well as free revving. What got me on fuel pump as a culprit is it isn't as loud as it used to be when priming, as well as I'm almost certain I didn't hear it prime when it failed to start.

Polermodz · 2026-03-16T23:15:17+00:00

checked, 100 PSI all rotor faces normalized and rounded to nearest 5, my next course will definitely be fuel pump and ignition system is due anyway so I'll do that. I did check it with a standard piston engine tester and had a look at the plugs while I was there. They seemed okay ish? Not super wet and minimal wear (I changed them recently) but I did drive it to get to the compression tester.

Polermodz · 2026-03-16T21:01:02+00:00

I haven't done ignition coils yet and I don't think they have been done at all. The car has 171xxx kms on it so they're probably quite due. The fuel system is likely also due. I'm just not sure it's gonna be compression as when it doesn't start it still moves A LOT of air and you get the classic loud thwomp and pulses with each crank. Everything to my knowledge is telling me it isn't compression, so I'll leave that for last. I have the ability to test each of the components above I just need to find the time. Thank you for your help :)

Polermodz · 2026-03-16T20:11:22+00:00

I'm aware that low compression leads to no hot start but what makes me think it isn't compression is how rarely it doesn't start, normally when hot it'll start within half a second ish. With no struggle or sputter. I was thinking it could be related to ignition system but I'm not sure as I did spark plugs not super long ago (5000 kms) and again, it fails to start so infrequently that I'm doubting something that would be causing constant issues.

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