Zero compression? Really?
01-22-2017, 03:24 PM
#1
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Zero compression? Really?
OK, Newbie with asbestos underwear installed!
2nd RX8 ever in the family, this one bought for less than peanuts as a project. I could break it and get more than I paid, but it is in good nick and they'll be sought after in a decade.
04 Series 1, 60k miles, minimal history, series of MOTs confirm mileage. Likely original engine. Engine starts promptly and I was able to drive it on and off the trailer and into the garage. Keeps wanting to stall and pathetic power, but will give a low lumpy idle for a wee while, with intermittent enormous backfires - it blew 3 beer bottles off the lower shelf in the garage 1m behind it. Impressive! Code says rotor 2 misfire. Coils/plugs/leads look new (the old coils are in the boot). Front rotor plugs a bit sooty, rear ones both pristine shiny metal as if straight out the box.
So I went for the DIY compression check (without the schraeder valve; with a video camera) just to see what ball park we were in; I am viewing it as a project and will rebuild the engine if it is required. Engine had to be cold as I'm feart to let it warm up in case it blows the new windows out of the garage. Front rotor is about 80-80-80 psi; rear is 0-0-0, not a flicker on the needle, not a whiff past a finger on the spark-plug hole. Is my assumption that complete and universal failure of all rear rotor seals the only explanation correct? I'm new to rotaries, but having done some research, there's no other way to get zero compression is there? Not like a bent valve etc.
thank you for reading!
2nd RX8 ever in the family, this one bought for less than peanuts as a project. I could break it and get more than I paid, but it is in good nick and they'll be sought after in a decade.
04 Series 1, 60k miles, minimal history, series of MOTs confirm mileage. Likely original engine. Engine starts promptly and I was able to drive it on and off the trailer and into the garage. Keeps wanting to stall and pathetic power, but will give a low lumpy idle for a wee while, with intermittent enormous backfires - it blew 3 beer bottles off the lower shelf in the garage 1m behind it. Impressive! Code says rotor 2 misfire. Coils/plugs/leads look new (the old coils are in the boot). Front rotor plugs a bit sooty, rear ones both pristine shiny metal as if straight out the box.
So I went for the DIY compression check (without the schraeder valve; with a video camera) just to see what ball park we were in; I am viewing it as a project and will rebuild the engine if it is required. Engine had to be cold as I'm feart to let it warm up in case it blows the new windows out of the garage. Front rotor is about 80-80-80 psi; rear is 0-0-0, not a flicker on the needle, not a whiff past a finger on the spark-plug hole. Is my assumption that complete and universal failure of all rear rotor seals the only explanation correct? I'm new to rotaries, but having done some research, there's no other way to get zero compression is there? Not like a bent valve etc.
thank you for reading!
01-22-2017, 03:58 PM
#2
It can happen. If an apex seal has shattered, that leaves a big gap. If its pieces then took out one other apex seal, no face will compress.
That explains the backfires, fuel goes into the rotor and goes right out the exhaust, then ignites in the exhaust. That's really bad, it could wreck the catalytic converter, which is expensive.
Do you have a way to look inside the rotor, such as an endoscope?
Just to check, you tested through the leading spark plug hole while the trailing plug was still in, correct?
That explains the backfires, fuel goes into the rotor and goes right out the exhaust, then ignites in the exhaust. That's really bad, it could wreck the catalytic converter, which is expensive.
Do you have a way to look inside the rotor, such as an endoscope?
Just to check, you tested through the leading spark plug hole while the trailing plug was still in, correct?
01-26-2017, 12:29 PM
#4
Biggest thing to look for is the apex seal going by the hole. it will be a silver shiny bar, running side to side. If you poke it with a small screw driver, it will really not move much. you will see the rotor face coming up slowly, then then the seal, then the next face going away. If you see a groove or hole, not good.
01-26-2017, 01:28 PM
#6
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dont listen to 9k, hes clueless. you can slide in new apex seals through the spark plug holes. should only take a few minutes
01-26-2017, 03:09 PM
#7
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I've already got a set of the new iron/copper/pottassium (FeKCu) seals. I intend to fit them through the holes after I've slid the replacement catalytic converter through.
01-27-2017, 02:00 PM
#10
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01-30-2017, 03:22 AM
#16
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Incidentally, how does an oil-burning engine get on with your emmission regulations, California especially?
01-30-2017, 09:42 AM
#18
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Join Date: May 2016
Location: Colo'freakin'rado
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Colorado is super strict about emissions... Unless you live in El Paso county/Colorado Springs. which means if my 8 doesn't sell, I can switch to a non catted resonator. Make fireballs! I failed my first emissions test, then finagled some things and passed the second.
02-26-2017, 07:39 AM
#19
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OK, started the dirty finger stuff. Following the how-to-remove-your-engine thread mentioned above. Extremely useful resource thank you! My steering wheel has been installed on the wrong side in the factory, so there are a few minor differences. Biggest so far was the euro-spec 1/4" steel tamper proof shielding round the ECU which makes it impossible to unplug the loom connectors. Dismantling electronics with an angle grinder doesn't seem right, but I had to do the same on a Renault a few months ago.
Browsing through the site and researching parts prices makes me think I'd be better buying a recon motor rather than trying to do it myself.
Browsing through the site and researching parts prices makes me think I'd be better buying a recon motor rather than trying to do it myself.
