STD Tuning Drivetrain Juttering at WOT in 5th gear

Juttering at WOT in 5th gear

Juttering at WOT in 5th gear

 
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Deni
GTA2056V

75
04-04-2010, 04:25 PM #1
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?

1992 Mercedes 190D 2.5 turbo 5sp manual. EGT+boost gauges. Boost controller set to ~14.5 psi. 1 1/4 turns on full load adjustment. LPG injection.

[Image: 3803751914_8fdca63138_o.jpg]
Deni
04-04-2010, 04:25 PM #1

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?


1992 Mercedes 190D 2.5 turbo 5sp manual. EGT+boost gauges. Boost controller set to ~14.5 psi. 1 1/4 turns on full load adjustment. LPG injection.

[Image: 3803751914_8fdca63138_o.jpg]

willbhere4u
Six in a row make her go!

2,507
04-04-2010, 08:22 PM #2
check you drive shaft / support bearing?

1987 300SDL 6spd manual om606.962 swap project
1985 300td euro 5spd wagon running
willbhere4u
04-04-2010, 08:22 PM #2

check you drive shaft / support bearing?


1987 300SDL 6spd manual om606.962 swap project
1985 300td euro 5spd wagon running

ForcedInduction
Banned

3,628
04-04-2010, 10:25 PM #3
With LPG, I'd bet its detonation.
This post was last modified: 04-04-2010, 10:26 PM by ForcedInduction.
ForcedInduction
04-04-2010, 10:25 PM #3

With LPG, I'd bet its detonation.

Deni
GTA2056V

75
04-05-2010, 08:54 AM #4
I'll check the drive shaft next time I'm at the mechanic.

FI, wouldn't detonation happen in other gears as well?

1992 Mercedes 190D 2.5 turbo 5sp manual. EGT+boost gauges. Boost controller set to ~14.5 psi. 1 1/4 turns on full load adjustment. LPG injection.

[Image: 3803751914_8fdca63138_o.jpg]
Deni
04-05-2010, 08:54 AM #4

I'll check the drive shaft next time I'm at the mechanic.

FI, wouldn't detonation happen in other gears as well?


1992 Mercedes 190D 2.5 turbo 5sp manual. EGT+boost gauges. Boost controller set to ~14.5 psi. 1 1/4 turns on full load adjustment. LPG injection.

[Image: 3803751914_8fdca63138_o.jpg]

ForcedInduction
Banned

3,628
04-05-2010, 09:15 AM #5
(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.
ForcedInduction
04-05-2010, 09:15 AM #5

(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.

Deni
GTA2056V

75
04-05-2010, 03:02 PM #6
(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 Big Grin)

1992 Mercedes 190D 2.5 turbo 5sp manual. EGT+boost gauges. Boost controller set to ~14.5 psi. 1 1/4 turns on full load adjustment. LPG injection.

[Image: 3803751914_8fdca63138_o.jpg]
Deni
04-05-2010, 03:02 PM #6

(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 Big Grin)


1992 Mercedes 190D 2.5 turbo 5sp manual. EGT+boost gauges. Boost controller set to ~14.5 psi. 1 1/4 turns on full load adjustment. LPG injection.

[Image: 3803751914_8fdca63138_o.jpg]

Deni
GTA2056V

75
04-06-2010, 04:32 PM #7
I checked the flex disc and it's fine.

1992 Mercedes 190D 2.5 turbo 5sp manual. EGT+boost gauges. Boost controller set to ~14.5 psi. 1 1/4 turns on full load adjustment. LPG injection.

[Image: 3803751914_8fdca63138_o.jpg]
Deni
04-06-2010, 04:32 PM #7

I checked the flex disc and it's fine.


1992 Mercedes 190D 2.5 turbo 5sp manual. EGT+boost gauges. Boost controller set to ~14.5 psi. 1 1/4 turns on full load adjustment. LPG injection.

[Image: 3803751914_8fdca63138_o.jpg]

willbhere4u
Six in a row make her go!

2,507
04-06-2010, 06:51 PM #8
it may just be the torque being applied through the flex disc causing it to deform under the extreme load

1987 300SDL 6spd manual om606.962 swap project
1985 300td euro 5spd wagon running
willbhere4u
04-06-2010, 06:51 PM #8

it may just be the torque being applied through the flex disc causing it to deform under the extreme load


1987 300SDL 6spd manual om606.962 swap project
1985 300td euro 5spd wagon running

Deni
GTA2056V

75
04-07-2010, 07:39 AM #9
(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?

1992 Mercedes 190D 2.5 turbo 5sp manual. EGT+boost gauges. Boost controller set to ~14.5 psi. 1 1/4 turns on full load adjustment. LPG injection.

[Image: 3803751914_8fdca63138_o.jpg]
Deni
04-07-2010, 07:39 AM #9

(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?


1992 Mercedes 190D 2.5 turbo 5sp manual. EGT+boost gauges. Boost controller set to ~14.5 psi. 1 1/4 turns on full load adjustment. LPG injection.

[Image: 3803751914_8fdca63138_o.jpg]

willbhere4u
Six in a row make her go!

2,507
04-07-2010, 01:19 PM #10
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

1987 300SDL 6spd manual om606.962 swap project
1985 300td euro 5spd wagon running
willbhere4u
04-07-2010, 01:19 PM #10

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


1987 300SDL 6spd manual om606.962 swap project
1985 300td euro 5spd wagon running

Deni
GTA2056V

75
04-10-2010, 01:49 PM #11
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 Smile.

1992 Mercedes 190D 2.5 turbo 5sp manual. EGT+boost gauges. Boost controller set to ~14.5 psi. 1 1/4 turns on full load adjustment. LPG injection.

[Image: 3803751914_8fdca63138_o.jpg]
Deni
04-10-2010, 01:49 PM #11

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 Smile.


1992 Mercedes 190D 2.5 turbo 5sp manual. EGT+boost gauges. Boost controller set to ~14.5 psi. 1 1/4 turns on full load adjustment. LPG injection.

[Image: 3803751914_8fdca63138_o.jpg]

Kozuka
I'm_Badass

334
04-11-2010, 12:54 PM #12
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
Kozuka
04-11-2010, 12:54 PM #12

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

 
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