101.000KM first engine, sudden compression loss and recovery. Stuck apex seal?
 

My 2004 Renesis HP was starting well hot and cold until, ironically, I passed the 100.000km milestone abroad. All of a sudden, hot starts were really difficult, and after several hot starts over the course of the week, it took me 3 tries of 10 seconds turning to get it running. The starter was fine, as it turned 300rpm, but felt as if there was no compression at all.

I guessed that the engine is toast, and after the last difficult start I decided to ride it hard, +200km/h on the Autobahn in 5th gear, letting the buzzer sing quite often. I've read about carbon buildup and some sticking apex seals, and guessed it would be worth the try to burn everything out of the engine. After the 200km trip back home, I tried starting after 1, 5 and 15 minutes, and suddenly everything seemed fine. I could feel the compression while the engine cranked, and it took less than 2 seconds to start the hot engine.

So, was it a stuck seal, or could there have been something else going on?

Wait a minute,,.. what about your rotor side seals,. They were new, did you cut them, or bought it already cut? I tried to cut those nastards and didnt work out for me, so i bought tjem cut by the leter and fixed the issue.

Might've been a bad fill of fuel. It went around Ireland for a while - with kerosene contamination in petrol. It killed quite a few boingers with carbon and melted pistons because they're so high compression these days

Had that happen to my RX - almost certain it got a fill of bad fuel. Car was sick, burning more than it should've, starting harder. Woke the fuck up with a fresh tank of new petrol.

A good Italian tune doesn't hurt, either.

My Rex runs on LPG, and whether it runs on Gasoline or LPG it's the very same problem. So it's not the fuel. It's also not the injectors or fuel pump, because on both fuels it starts just as bad.

Could be that the ignition didn't fire, because the CAT temp only increased as soon as the engine actually got over 500rpm and started. The plugs are sparking, but maybe not strong enough? I have no clue. The problem in November 2016 went away in April, come back in June again, now the car sounds like a Smart ForTwo, starts worse then ever. Every time I start the engine, it's terribly flooded. Guessing it's the MAF at the moment because the numbers are all over the place at WOT.

Got a pulsating air sucking sound recently, car barely starts, barely runs, misfires, shaking engine. Blown sideseal? Or just stuck? Sucking noise comes from behind the Upper Intake Manifold. Problems started in November, gone in December, came back in January, gone in April and May, June July it came back and now it really crapped out.

The starting issues are very erratic.


I will seafoam the shit out of it soon and see what it does. WOT is 175 g/s.

Keeping the Engine at an Idle
• Ignition Coils
• Spark Plugs
• Spark Plug Wires
• Engine Compression
• E-Shaft Sensor (ESS)
• Mass Air Flow Sensor (MAF)
• Front O2 sensor
• Catalytic Converter (Cat)
• Intake Vaccum


Engine Power Loss
• chokes as revs increase
o O2 sensor failure (too rich)
o MAF failure
o MAF disconnected
o e-shaft sensor fouled
o accessory belt fraying
• high end power loss (hard fuel cut)
o Rev limit reached
• high end power loss (jerky and stumbling)
o Ignition failure
o fuel pressure loss
o e-shaft sensor fouled
• high end power loss (smooth)
o Catalytic converter clog
o air filter clog
• low end power loss (smooth)
o Engine compression loss
• low end power loss (stumbles)
o Ignition failure
o front O2 sensor failure
• revs slowly but smoothly
o O2 sensor failure (too lean)
o catalytic converter clog
o air filter clog
• sudden power drop at a specific rpm
o Intake valving actuation problem
• trouble getting to redline
o Ignition failure
o front O2 sensor failure
o catalytic converter clog
o air filter clog
o e-shaft sensor fouled
o fuel pressure loss
o MAF failure

Went for a 50km drive today, redline a few times. Last 5km and 5 min were through the suburbs at 30-50km/h. When I parked the car and looked underneath at the cat, I've seen through a hole in the heatshield that the cat is glowing red/orange.


My car sounds like the rx of this guy when I try to start it: How my car sounds:
Sucking noise I hear from the engine: Is the same rythm of the blasts I get out of my exhaust:
P0336 code has been fixed, cleaned the sensor, but nothing changed in starting performace. I will inspect the cat next time and if it's clogged, gut it.

Your cat's bollocksed if it's glowing. Get it out of there now or your engine is dead.

It may already be dead - if you're the same gentleman on reddit who ran 30k km on the one fill of synthetic oil, only topping up the whole time, on a short running cycle.

We'll find out this saturday when I hammer the bad kitty to bits.

Ok, kitty seems fine. Replaced it with a new kitty but this one is glowing aswell.

Unburnt mixture is sent into the kitty and making it glow. New Coils replaced with old well working Coils, no Change.

Rear rotor
Trailing plug: Coffee Brown
Leading plug: Black

Replaced leading plug with other known well working leading plug, no Change.

Last Weekend when I had to start the car with the help of a hill, it ran horribly rich and left the street blue of smoke. Only get misfire codes during first few seconds of starts, if at all.

Car seems to run excessively rich.

MAF Reports 7g/s on idle (TSB dictates 3 to 4 something), and 2500rpm Reports 15g/s (should be 9 to 11). WOT close to redline is 170g/s. Bought a new DENSO MAF, will see what it does.

Engine core is soaked in fluid. Top is sweaty, down the line it just gets super wet and flooded. Leaky Gasoline injector? Oil injector? It's all around the engine. Other fluids are all fine.

I will swap the new plug wires with old plug wires, could be that the NGK ones are dead? I have measured the resistance when I bought them so I can check that again. They seem thinner although written it is for an RX8.

Also, ENGINE IDLES ON 4 INJECTORS according to my diagnostic tool. How is this possible??? (Check at 0:45)
Same diagnostic tool like this one: Same RX8 Version, same diagnostic tool, yet he only has 2 injectors on low load, and I have 4 on idle?