Technical Riiculously shaking when accelerating, also Engine mounts question

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Technical Riiculously shaking when accelerating, also Engine mounts question

ruispeed3d

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Hi Everyone, hope you're all well and healthy.
I have a stilo hatchback 1.9jtd115 and i've been having a ridiculous shake(not really vibration) when i accelerate at speeds around 50-60mph(80-100kmh) and so on. As soon as i lift my foot from the pedal it stops completely and as soon as i press it again there it is again with all its might.

what is creating this kinds of shakes? Engine mounts would be my first guess but i'm not capable of telling if my mounts are any bad or good so i'll attach pictures of them so that you can give me your opinion about their state if you can. For me both of them look kinda old and fatigued, especially the gearbox mount, it feel like it's already resting on some sort of safe stopper preventing it from falling to the floor, but i don't know their normal working state, it could be normal.

Lastly i would like to ask you if you have any pictures of these mounts, old or even new, to attach them. I would like to compare them to mine.

thanks in advance.

Take care,
Rui Louro
 

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Ralf S.

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That last one doesn't look too good.

If you start the engine and open the bonnet, then have a look at the engine. If it's moving around then the mounts (one or more) are shot. If it's vibrating a bit but otherwise is not moving, then the mounts are probably okay. The bone shaped mount behind the gearbox/sump is the one I hear of that fails most often.

If the mounts are good but you still get a vibration then it could be a clutch flywheel issue. The JTD115 has a dual-mass flywheel, which usually last for several clutches.. but yours could be knackered. The flywheel would tend to vibrate on the over-run though, rather than accelerating.. (the opposite to what you get) so.. I'd look at the mounts first.


Ralf S.
 
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ruispeed3d

ruispeed3d

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That last one doesn't look too good.

If you start the engine and open the bonnet, then have a look at the engine. If it's moving around then the mounts (one or more) are shot. If it's vibrating a bit but otherwise is not moving, then the mounts are probably okay. The bone shaped mount behind the gearbox/sump is the one I hear of that fails most often.

If the mounts are good but you still get a vibration then it could be a clutch flywheel issue. The JTD115 has a dual-mass flywheel, which usually last for several clutches.. but yours could be knackered. The flywheel would tend to vibrate on the over-run though, rather than accelerating.. (the opposite to what you get) so.. I'd look at the mounts first.


Ralf S.
Thank you for your answer. I already had a look at the engine when it's working and it behaves like you said, it vibrates a bit but doesn't move around at all, but still, i'm not removing them from the equation.

A new engine mount is already on the way but i'm considering getting the gearbox one cause as you pointed out, it looks a bit knackered, like it's resting solely on the top bracket that's isolated from the mount underneath by a thin layer of compressed and dry rubber, and when i accelerate it could be bouncing up and down creating that incredibly uncomfortable shake.

If everything goes to sh*t and changing all the mounts do nothing i think it's time to look at that flywheel/clutch. They are already packing some serious millage and are in need of some tlc.

thank you and take care.
Rui L.
 

Ralf S.

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Driveshafts tend to grumble more when the suspension is unloaded, such as when you accelerate.. but you would also hear them when the car goes over a crest.

I wouldn't describe the grumble as a "shake" though. When mine packed up, it was more of a vibration... and they were pretty bad. When I took the driveshaft out of the cup, one of the rings just came off. Most of the roller bearings were still in there.. but I counted about 6 that were missing/ground into mush.

My flywheel is still (2 years) overdue to be changed.. just waiting for the lockdown to end so I can do it on my old mum's drive... and warmer weather/longer days... Again, that's making a rumble/grumble which disappears at higher speed.. and I would be hard pressed to describe it as a "shake". :)

Ralf S.
 

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Mike1alike

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I've had recently kind of this sort of problem. Only it was manifesting at lower speed, just when changing the gear being in 2nd. If the rev was under 2000 RPM it would shake and judder realy bad. I solved it by cleaning the injectors. First using petrol additive, but that have not done the job completely. But after using it, the shakes almost disappeared and came back occasionally. Then I took the injectors out and cleaned them with carb cleaner spray. The car runs smoothly now, no shake since. Also, the gas/miles numbers have improved.
Now I am curious, a friend is having exact same problem and the shakes are even worst than mine were. I advised him to clean the injectors and he did it. Just that he has an older car and took the injectors out of that one and cleaned them and he did not put them on the car he drives yet. As I've mentioned, I'm curious if this would fix the shaking on his car, too.
 
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With mine.. its a diesel..

It pulses.. and basically pushes the steering

ONLY under acceleration

Only @40mph (50/55 mph) roadspeed

GEAR : Engine revs have minimal effect

Thats why I'm 95% sure its driveshafts

Now the UK weather is improving I can strip and inspect the other side (swapped Drivers tripod last year with little effect)
 

Ralf S.

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I wonder if your cups are worn. On mine, the spiders wore little grooves into the insides of the cups, so fitting new spiders improved things, but not completely. The one that was destroyed (o/s) somehow was less bad than the one on the nearside side.

Eventually I had to change the n/s driveshaft, when the outer CV also failed and it was cheaper to buy a whole brand new driveshaft (J&R?) rather than just to replace the CV. That sorted out the noise on the nearside almost completely.

But since then my flywheel has started to go AWOL occasionally. It's the factory original item, so I can't begrudge it. That also causes a vibration.. mostly around 1500rpm.. but now and then the gearchange becomes stiff/reluctant until I've pumped the pedal a few times and it settles down again. New everything including a gasket is waiting for the better weather..


Ralf S.
 
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ruispeed3d

ruispeed3d

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Hi everyone,

Thank you for taking some time to express your opinions and experiences on this thread.

Regarding my problem, it still persists but this next weekend i'm gonna try to replace all my engine mounts for new ones that i already have and see where that gets me.

Curious enough, since some of you talked about it, i have a cv joint that's in need of attention(driver's side,inner cv joint), it's rubber boot has a tear near the clamp and made a mess of it's surroundings. I'm gonna change the hole half shaft in the near future.

I doubt it is the cause of my shaking though, because, at least right now, i'm not hearing any clicking or knocking sounds when turning or driving and i only experience this shakiness at "high" speeds. If my cv joint was causing that amount of shake i think by now it would have already disintegrated. But i'm not a mechanic, so i'm not removing it from the equation, we never know.
 
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ruispeed3d

ruispeed3d

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I wonder if your cups are worn. On mine, the spiders wore little grooves into the insides of the cups, so fitting new spiders improved things, but not completely. The one that was destroyed (o/s) somehow was less bad than the one on the nearside side.

Eventually I had to change the n/s driveshaft, when the outer CV also failed and it was cheaper to buy a whole brand new driveshaft (J&R?) rather than just to replace the CV. That sorted out the noise on the nearside almost completely.

But since then my flywheel has started to go AWOL occasionally. It's the factory original item, so I can't begrudge it. That also causes a vibration.. mostly around 1500rpm.. but now and then the gearchange becomes stiff/reluctant until I've pumped the pedal a few times and it settles down again. New everything including a gasket is waiting for the better weather..


Ralf S.
One last thing, i was wondering if you or everyone else would know all the torque settings needed for each individual mount on this engine(jtd115 8v).

i searched the elearn software but regarding the gearbox mount it only had information about torque settings available for the jtd 16v, are they the same?

About the lower mounts, Reaction Rods as elearn calls them, i haven't found that information either, only settings for the petrol models are displayed. The other mounts they talk about for my car seem to be regarding rigid mounts(which i dont think that is what these are) or other stuff i dont really know about or what they are. the torque on these ones are any similar to the petrol ones?

Thank you in advance.
Rui Louro
 
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Hi everyone,

Thank you for taking some time to express your opinions and experiences on this thread.

Regarding my problem, it still persists but this next
I doubt it is the cause of my shaking though, because, at least right now, i'm not hearing any clicking or knocking sounds when turning or driving and i only experience this shakiness at "high" speeds. If my cv joint was causing that amount of shake i think by now it would have already disintegrated. But i'm not a mechanic, so i'm not removing it from the equation, we never know.

Split boots mean 2 things..

Loss off Grease - Bad

Grit in the remaining grease - Worse

https://www.fiatforum.com/miscellaneous-guides/79388-how-check-driveshaft-wear.html?p=2651208
 
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ruispeed3d

ruispeed3d

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Hi everyone,

I have an UPDATE. I changed all of my mounts. Gearbox mount, both bottom mounts and the engine mount. I did it myself with help from a friend and it was a relatively easy job to do(with the right tools to do it).

But unfortunately it did not removed the shakiness, only damped it a little bit (cause of the new rubber on the mounts i suppose).

I noticed improvement on the overall vibration on the car and it runs much smoother on lower speeds(city driving) and at idle, but as soon as i start to reach speed higher than 70kph(~43mph) all hells breaks loose again and the car starts to shake again, not as rough as it was, but it is still there.

The time to change my clutch and flywheel might have arrived as i'm not seeing what else could possibly be causing this. When i lifted the car to change the bottom mounts i didn't notice anything loose or out of place, only a rubber boot of the cv joint(left side, inner joint) has a tear and lost most of the grease but as some of you pointed out, it normally should only show symptoms at lower speeds, like vibrations or cracking noises.

thank You
 

lunchbeers

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I might have missed this, but seems nobody has mentioned tyres or wheel alignment?

My last car had an alarming shudder at 70+mph, but was otherwise fine around town or at lower speeds, turns out one of the cheap tyres fitted by the previous owner had knackered apparently.

Had all the alignment checked and tyres changed for premium ones and balanced, and all was well again.
 
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ruispeed3d

ruispeed3d

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I might have missed this, but seems nobody has mentioned tyres or wheel alignment?

My last car had an alarming shudder at 70+mph, but was otherwise fine around town or at lower speeds, turns out one of the cheap tyres fitted by the previous owner had knackered apparently.

Had all the alignment checked and tyres changed for premium ones and balanced, and all was well again.
Hi lunchbeers, thank you

That shudder must be very similar to what i'm experiencing but mine only appears every time i accelerate and it happens at speeds over 40 mph(at least that's when i start to feel it).

If i accelerate until i reach like 90 mph it does it every time but as soon as i let go of the throttle it immediately stops, it basically starts as soon as i put load on the engine to speed up.

that's why i discarded wheels/alignment cause if that was to blame, that shudder would be constant, whether i accelerate, decelerate or driving at cruise speeds, i'm almost certain of that.
 

lunchbeers

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It rounds similar to mine, it was a couple of years back, so can't remember the exact circumstances, I thought it was worn driveshaft cups, which was a recognised fault.

Having your tyres checked for balance and a wheel alignment would be my first port of call, and likely the cheapest option.
 
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