HEAVY engine vibration

[sen2two]

(not my car)


S5 TII fresh rebuilt motor, timing is good, TPS is good, has spark/fuel to both rotors, no vacuum leaks, AFM is good...

Hard to start without holding the pedal down slightly. when it actually does idle at around 650-700 it sounds ok, not great, but ok. the second you try and rev it up, the engine shakes VERY HARD. The higher the RPM the worse it shakes. Its kinda similar to running on one rotor, but not so much...

any ideas? im stuck here...

[Kentetsu]

I'd check the ignition to make sure he's still got spark, but really it sounds like he tossed an apex seal. :(




.

[classicauto]

whats the story on the plugs?

Seen new plugs foul almost instantly from being gobbed with vaseline/assembly lube after the first start up. I'd toss a fresh set in and just see what happens.

[sen2two]

not an apex seal. its a fresh rebuild with RA seals. has great spark to all four plugs also...

never seen anything like this before. the only thing that comes to mind is kinda far fetched... Maybe someone in the past swapped rotors in this motor. the rotors could be far enough off balance to cause this vibration.

[sen2two]

whats the story on the plugs?

Seen new plugs foul almost instantly from being gobbed with vaseline/assembly lube after the first start up. I'd toss a fresh set in and just see what happens.

thats was my first guess also. no luck... Its using B9ES plugs also, wich are plugs for jet skis. And are EXTREMELY hard to foul out. Thats the reason i use them for start up... I also use them in my personal car year round.

[classicauto]

I dunno about the mismatch rotors. I've run a S4 flywheel on an S5 (out of necesity for a breif period of time) and even with that I didn't really get any vibration you could detect just running the car. I'm sure it was wobbling due to the rear bearing being shot after :lol: but no noticeable engine vibration at all. And I'd think that difference is greater then one wrong weight rotor......but....its uncertain.

Usually a heavy vibration like this is a misfire - which system its related to though I can't say for sure but would bet ignition.

Have you tried rotating the CAS with it runnning and revving and see if gets worse or better?

[FerociousP]

djmtsu's engine had good (tested) compression, spark, ran "ok" but not great at idle, sounding like it was running on one rotor but "not", and would make crazy noises when revved... he determined he lost an injector (or a good injector went weak/clogged/etc.) while driving and eventually spun a bearing which now has low oil pressure..

how's your oil pressure?

[TitaniumTT]

whats the story on the plugs?

Seen new plugs foul almost instantly from being gobbed with vaseline/assembly lube after the first start up. I'd toss a fresh set in and just see what happens.

That would be my first guess as well. I've had new plugs foul within 15 minutes of running from being gobbed up. Just all of sudden lost rotor..... stupid D580 coils

I dunno about the mismatch rotors. I've run a S4 flywheel on an S5 (out of necesity for a breif period of time) and even with that I didn't really get any vibration you could detect just running the car. I'm sure it was wobbling due to the rear bearing being shot after :lol: but no noticeable engine vibration at all. And I'd think that difference is greater then one wrong weight rotor......but....its uncertain.

Usually a heavy vibration like this is a misfire - which system its related to though I can't say for sure but would bet ignition.

Have you tried rotating the CAS with it runnning and revving and see if gets worse or better?

Maybe of it's two rotors from different series, different weights it might be off enough to FUBAR it.

My guess would be start at the ignition. Just becuase they're new plugs doesn't mean they;re not fouled. Just becuase they're new wired doesn't mean they're fuctioning properly. Just becuase they're new injectors, doesnt' mean they work either..... speaking of, what the story behind the injectors? I've heard rumors about the cleaning agents they use corroding the injector's frozen if they sit for long enough after a cleaning. Might wannaa send them out and see if they're in tip top shape.

[djmtsu]

Does it sound like this:

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[Lastphaseofthis]

wow.. ^ that shit's fucked up.


OP,-maybe flywheel is not on properly? or it sheared the key? take it off and look.

[Max777]

I had a the center bushing in my transmission cross member sag and break, when I put in the Banzai Poly bushings, it was terrible. Bought a new crossmember, and it got a lot better. I still need to replace my drive shaft and tires, but otherwise I cna drive the car under 50mph. I also think I have soem high rpm hesitations because the resistance on my TPS reads 7.1K at WOT, when it should read around 6K tops.

Hope this info helps somewhat.

[sen2two]

Well, the plugs look great but, i'll try a new set anyway... I was also just informed that the gas thats in the tank has been there for over 2 years.

Hopefully some new gas will remedy this...

[TitaniumTT]

:facepalm:

Yeah, I'd also send out those injectors as well. If the gas has been sitting that long, the injectors have probably been idle that long and I would think could use a little lovin'

[sen2two]

lol... cars not mine. As far as i knew, the gas was fairly new.

[sen2two]

new gas, new plugs... same problem.

WTF...

[project86]

is it possible one of the motor mounts is broken? loose?

[sen2two]

new poly mounts...

[TitaniumTT]

make sure all coils are visibly firing, send injectors off

[jerd_hambone]

Just give the car to me. I'll take care of it. Haha