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Intermittent Violent Engine Shaking


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32 replies to this topic

#1 JEBalles

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Posted 22 October 2012 - 10:04 PM

So Ru has recently developed a problem that I can't explain. It first occurred when I was driving about 85 in fifth gear and the engine (I think) started shaking worringly violently. It appeared to be related to throttle position and if I popped her into neutral, it went away. Pulled over and revved the engine some-nothing, felt great. Got back on the highway and kept it at 65 until I got home and was fine. Water temp, oil pressure all fine.

City driving is fine.

Driving again on the highway, this time on some hills as well. Started out fine, took the hills like a champ. Then the shaking came back, again intermittently.

The only way I can describe the shaking is it feels like driving a diesel that has air in the lines. I'm not sure if a gasser feels the same way and I'm not sure if there was any power loss, but then again, I think I tend to let off the throttle if it starts doing it.

Does anyone have any idea? I'm at a loss

#2 JEBalles

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Posted 22 October 2012 - 10:29 PM

'89 GL wagon with dual-range 5-speed and SPFI EA82, I forgot to mention

#3 naru

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Posted 22 October 2012 - 10:38 PM

Fuel filter

#4 nipper

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Posted 22 October 2012 - 11:23 PM

What makes you think it is the engine?

When was the last time the car had a tune up?

How old is the ignition coil?

#5 JEBalles

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Posted 23 October 2012 - 12:03 AM

Just based on my experience with other shaky engines. When my diesel would get air in the fuel lines, it would feel like it's about to shake off it's mounts and it's a similar feeling. And it seems more load dependent than speed dependent.

I got the car over the summer and it had been sitting before then, so I have no idea the last time it got a tune up. Same goes for the age of the ignition coil. Is that something that could do it? Like an intermittent spark issue?

#6 Gloyale

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Posted 23 October 2012 - 09:48 AM

Just based on my experience with other shaky engines. When my diesel would get air in the fuel lines, it would feel like it's about to shake off it's mounts and it's a similar feeling. And it seems more load dependent than speed dependent.


This is very different than a diesel.

I think you have an axle issue.

Shaking under load = CV axle on it's way out

#7 nipper

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Posted 23 October 2012 - 09:50 AM

Thats what I am leaning towards, a very bad axle. Engines do not shake at speed usually it is at idle, or they are about to fall out of the car, or blow up. The last one if it does shake, it doesnt happen for very long untill there are parts everywhere.

#8 JEBalles

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Posted 23 October 2012 - 11:10 AM

Yeah, that was my only idea was the axle. Maybe it's moving around in it's mount which could cause it to be intermittent?

Is there anyway to check the axles? And if I decide it is them, should I replace the whole assembly?

The only thing that makes me think that it's not the axle is that it does shake a lot. That's why I used the diesel analogy for the feeling, because it feels like a large mass (such as the engine) is rocking around in the front of the car. I'm just not sure if the axle can cause that.

#9 nipper

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Posted 23 October 2012 - 11:11 AM

Just grab the axle and shake it, I bet you will find something disturbing.


Also any oddness in tight turns, noise, vibration etc?

#10 JEBalles

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Posted 23 October 2012 - 03:03 PM

Tight turns are fine, and I drive like a mad man so I think I'm taking whatever components are stressed during turns to their limits. It's only happened on the highway so far.

#11 El Presidente

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Posted 23 October 2012 - 03:19 PM

I had a very similiar experience recently and it turned out to be a bad inner cv joint(DOJ, near the tranny). When it would start shaking(only on the freeway) it felt like the wheel/tire was trying to do whatever it could to not be on the car anymore..it got my attention, especially when its a 30" mud terrain on a heavy steel toyota wheel. I'd check those inner joints

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#12 AKghandi

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Posted 23 October 2012 - 03:59 PM

I too had a very voilent shaking at highway speeds turns out some one removed the flat washers on both front cvs..the axle nuts were tight luckily. Vibrated really hard shaking the whole dash and making the steering wheel dance..replaced the flat washers and got the wheels balanced.

All good now.

#13 scoobiedubie

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Posted 23 October 2012 - 05:47 PM

The distributor may require some rebuilding or replacement. The vaccuum advance system gets sticky, so that when you decelerate, the advance remains stuck at the higher rpm setting. If you take your distributor apart, you may see that two plates rotate relative to each other, with several ball bearings between them. The ball bearings get worn out and irregular grooves or dirt inhibits the travel of the corroded and pitted bearings. Although the bearings can be easily replaced from an ACE hardware and the dirt cleaned off, the irregular groove remains.

#14 Gloyale

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Posted 24 October 2012 - 10:07 AM

The distributor may require some rebuilding or replacement. The vaccuum advance system gets sticky, so that when you decelerate, the advance remains stuck at the higher rpm setting. If you take your distributor apart, you may see that two plates rotate relative to each other, with several ball bearings between them. The ball bearings get worn out and irregular grooves or dirt inhibits the travel of the corroded and pitted bearings. Although the bearings can be easily replaced from an ACE hardware and the dirt cleaned off, the irregular groove remains.


Uh............there is no way a sticking advance is causing his car to shake under load.

Espescially when you consider his car is SPFI, and doesn't have a Vaccum, or centrifugal advance.

this is an Axle issue.

Axle binds as it rotates, and tries to lift the Engine and Trans up off it's mounts.

#15 ivans imports

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Posted 24 October 2012 - 10:16 AM

iceing up ? no coolant flow thru T B or bad ground on coil boltup bracket bad coil wire. A feul fillter whould only do it when under heavy load uphills or long hyway accelerations. Or diss cap has a crbon track or rotor is arcing to center shaft of disstributor anything high tention whould be worse under load.

#16 naru

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Posted 24 October 2012 - 10:38 AM


this is an Axle issue.

Axle binds as it rotates, and tries to lift the Engine and Trans up off it's mounts.


Why only at freeway speeds?

#17 naru

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Posted 24 October 2012 - 10:46 AM

iceing up ? no coolant flow thru T B or bad ground on coil boltup bracket bad coil wire. A feul fillter whould only do it when under heavy load uphills or long hyway accelerations. Or diss cap has a crbon track or rotor is arcing to center shaft of disstributor anything high tention whould be worse under load.


85 mph in 5th gear= very high fuel demand
problem disappeared at 65 mph(less fuel required)

!`d check the fuel filter/pressure first

#18 JEBalles

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Posted 24 October 2012 - 01:53 PM

Alright, haven't checked fuel or spark yet, but upon a visual inspection of the axles, I found the inner boot of the driver's side front axle to be torn. None of the axles felt loose or anything. Could a torn boot (and therefore worn inner components) cause this?

#19 ABawm 88 GL

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Posted 24 October 2012 - 09:43 PM

It could be the u joints on your driveline?

#20 6 Star

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Posted 24 October 2012 - 10:06 PM

It could be the u joints on your driveline?


Hes most likely in fwd when travelling on the freeway, so I doubt that is the cause.



Alright, haven't checked fuel or spark yet, but upon a visual inspection of the axles, I found the inner boot of the driver's side front axle to be torn. None of the axles felt loose or anything. Could a torn boot (and therefore worn inner components) cause this?


If it has been torn a long time then it most likely has grit inside and is starting to fail. This was the problem in my Brat. Replaced both front c/v's and the horrible shaking went away.

#21 nipper

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Posted 24 October 2012 - 10:36 PM

Torn boot will do it (allow for the joint to fail), especially if it has been there a long time.

#22 ABawm 88 GL

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Posted 24 October 2012 - 10:36 PM

I converted to RWD so my mindframe is all out of whack.

#23 ferp420

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Posted 25 October 2012 - 09:41 AM

I like the fuel filter idea and it's cheap fix worth a try

#24 nipper

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Posted 25 October 2012 - 10:02 AM

What is happening is ocasionally the shaft is seizing in the joint so it doesnt not sit in the center of the driveline. When it is off center, it will shake violently. Gte this fixed as it will only get worse, and can actually shake the car apart.



Fuel filter would be bucking or loss of power.

#25 naru

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Posted 25 October 2012 - 10:06 AM

What is happening is ocasionally the shaft is seizing in the joint so it doesnt not sit in the center of the driveline. When it is off center, it will shake violently. Gte this fixed as it will only get worse, and can actually shake the car apart.



Fuel filter would be bucking or loss of power.


Why only at freeway speeds?




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