2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

zero compression

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Old Jan 31, 2006 | 01:32 AM
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sleeepyhead's Avatar
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zero compression

I "blew" my engine when the throttle got stuck on my car and it saw 20psi at 8000rpm. I set my ecu at full rich on the stock injectors to try and save the engine from stuff like that but it didnt help. When it "blew" i didnt hear any weird noise or anything, It just had no more go and shook badly at idle after the throttle stuck. Afterwards I checked compression and had 0-0-0 front and 95-95-95 rear. When I pulled the engine, I checked and all three apex seals were intact. My friend assumed that was true cause the turbo was still spooling well on one rotor and a apex would take that out too. If I have 0 compression on the front and the apexes are still there, what could have gone wrong? Blown soft seals like oil and coolant? warped or cracked housings? I want to know if parts of that engine are still salvagable
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Old Jan 31, 2006 | 01:35 AM
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ur pretty much gonna get a bunch of "wont really know til u rip her apart"
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Old Jan 31, 2006 | 01:41 AM
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you may think the apex seals are intact but maybe pulling the engine apart will tell a different story, how did you check their condition?
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Old Jan 31, 2006 | 01:52 AM
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the front rotor just disappeared... but seriousely you might have blown a soft seal like you said. It will take some dimantling to find out what's wrong though.

TR
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Old Jan 31, 2006 | 02:18 AM
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Open her up and find out.
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Old Jan 31, 2006 | 02:24 AM
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a soft seal failure will not result in 0 compression.
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Old Jan 31, 2006 | 02:29 AM
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yeah a coolant could have failed, how full is your radiator?
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Old Jan 31, 2006 | 02:30 AM
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Originally Posted by carzy driver
yeah a coolant could have failed, how full is your radiator?

did you read my post or just ignore it completely?
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Old Jan 31, 2006 | 02:34 AM
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why not?
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Old Jan 31, 2006 | 02:37 AM
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seal could have failed, at 8k rpm a rotary would make a hell of a water pump, drained enough coolant to cause it to overheat
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Old Jan 31, 2006 | 02:40 AM
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but it would still have compression, blown coolant seal engines still run perfectly fine however they are hard to start and overheat quickly.
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Old Jan 31, 2006 | 02:45 AM
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what if it's warped from overheating? He also never mentioned he tried starting again.
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Old Jan 31, 2006 | 02:47 AM
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you could have damaged a seal from the overrevving. Maybe smash the apex seals or side seals? The stock tach is slow, so it could have been way higher than the 8000rpm that you noted.
I'm positive that 20psi helped in no way either. Could be a combination of the too! You could be the first to destroy all 6 sideseals and 3 apex seals on one rotor......
When I blew my motor I had 100 all around on the front rotor and 0-0-0 on the rear and I was damn proud to blow more than one apex seal.

I know my throttle got stuck on a few occasions from the OMP rod overlapping its throttle connection.
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Old Jan 31, 2006 | 02:50 AM
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i think there is more to the story, more than likely if the seals are in place something happened to the stat gear and the rotor collided the rotor housing which in turn stuck all the apex seals in place.
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Old Feb 1, 2006 | 12:44 AM
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to check the seals i looked thru the exhaust ports and they were still there. If it blew wouldnt the hotside of the turbo get destroyed? I actually drove it to work after it blew and back home where I layed it to rest. The rpm reading was off my laptop cause I was running a microtech. Ill open it up when I have the time, just curious as to what can cause completely zero compression. Also when I drove it on one rotor, it doesnt smoke at idle or cruise, just when I rev it up (need to so I can go past 5mph)
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Old Feb 1, 2006 | 12:52 AM
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off topic question, what turbo were you running that saw 20 psi?
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