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+--- Thread: Juttering at WOT in 5th gear (/showthread.php?tid=1256)
Juttering at WOT in 5th gear - Deni - 04-04-2010
Hi,
I need help with diagnosing lots of juttering coming from the rear at WOT in 5th? The car feels like a rear tire exploded and starts vibrating in the back when I got WOT in 5th.
Is it the clutch or dual mass flywheel?
Also, the juttering happens only when LPG is on, so when more torque is applied.
Any ideas?
RE: Juttering at WOT in 5th gear - willbhere4u - 04-04-2010
check you drive shaft / support bearing?
RE: Juttering at WOT in 5th gear - ForcedInduction - 04-04-2010
With LPG, I'd bet its detonation.
RE: Juttering at WOT in 5th gear - Deni - 04-05-2010
I'll check the drive shaft next time I'm at the mechanic.
FI, wouldn't detonation happen in other gears as well?
RE: Juttering at WOT in 5th gear - ForcedInduction - 04-05-2010
(04-05-2010, 08:54 AM)Deni FI, wouldn't detonation happen in other gears as well?
The load in 5th gear is much higher/hotter since the engine can't accelerate as quickly and runs at lower rpms.
RE: Juttering at WOT in 5th gear - Deni - 04-05-2010
(04-05-2010, 09:15 AM)ForcedInduction(04-05-2010, 08:54 AM)Deni FI, wouldn't detonation happen in other gears as well?
The load in 5th gear is much higher/hotter since the engine can't accelerate as quickly and runs at lower rpms.
The vibration happens even when:
While traveling at around 58 mph at around 2000 rpm, about 4 psi boost, press the pedal at maximum. At around 5psi lpg turns on. Boost increases to about 16psi and stays there (engine is turning about 2100-2150 rpm) and the vibration begins. All this happens in about 2-4 seconds. If I ease the throttle just a bit the vibration goes away.
To me it looks like it's related to torque rather than detonation ( I know you're against LPG
)
RE: Juttering at WOT in 5th gear - Deni - 04-06-2010
I checked the flex disc and it's fine.
RE: Juttering at WOT in 5th gear - willbhere4u - 04-06-2010
it may just be the torque being applied through the flex disc causing it to deform under the extreme load
RE: Juttering at WOT in 5th gear - Deni - 04-07-2010
(04-06-2010, 06:51 PM)willbhere4u it may just be the torque being applied through the flex disc causing it to deform under the extreme load
Any idea how I can solve this?
RE: Juttering at WOT in 5th gear - willbhere4u - 04-07-2010
The only way I can think of is a custom drive shaft that eliminates the flex discs and center support? You would want to make sure that is the problem first! maybe put a camera under there and take a video
RE: Juttering at WOT in 5th gear - Deni - 04-10-2010
The shaking seems to be coming from the rear.
I'll post this once in the finnish forums. I guess they've seen lots of torque before
.
RE: Juttering at WOT in 5th gear - Kozuka - 04-11-2010
When was the last time you did your rear sub-frame bushings? This could be a sign of worn subframe, diff, 5-link, sway bar bushings. Check them all. Dry-rotted/Cracked = Replace