front end jolt

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sym
1.8 16v
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front end jolt

Post by sym »

im getting a jolt on the front end of the 406, if im in 3rd gear doing about 25 & take my foot off the throttle i get a jolt & the gear lever moves slightly, it also does it if i accelerate from around the same speed, it happens on & off the throttle, so far ive changed the near side mount,lower mount & the fork & the dogbone mount, only one ive not changed is the offside engine mount, any suggestions to where to look would be gratefull, thanks lee
madmadmax
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Re: front end jolt

Post by madmadmax »

i did not read the post
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steve_earwig
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Re: front end jolt

Post by steve_earwig »

Now write it out 100 times :cheesy:

Umm, look at the offside engine mount? I'm not sure why it would be speed related though, at least not only in a specific gear :?
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keppler
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Re: front end jolt

Post by keppler »

When my offside engine mounting needed changing I could feel an excessive amount of judder when releasing the clutch from stationary also when performing the same procedure the knackered mount was sending a hell of a lot of vibration along the car through the drivers side door, even the passenger window used to vibrate sometimes. I suppose the question to ask yourself is, did the car feel better every time you changed another mount? If it did (like my car did) then I would strongly suggest you change the last mount. If you've been driving for a long time with the bottom engine mount disintegrated then its probably put alot of extra stress on the other 3 mounts. The way I recommend checking them is to get someone to start the car while you stare at the mount. Do this with the brand new gearbox mount first then repeat with the drivers side mount. If the mount is tired there should be a lot more movement in the drivers side.
If this mount turns out to be the culprit then I'd be really surprised because you should be getting a bucket load of judder and vibrations especially in low revs.
Another thing to try is to sit in the car with all doors and windows closed, put the car in neutral and just slowly and gradually rev it from idle to about 2krpm. if you notice that the engine sounds a bit grumbly and rough in the lower half but then just suddenly sounds smooth from say about 1400/1500 rpm up then id say your mount is definitely in need of replacing.
sym
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Re: front end jolt

Post by sym »

update. all engine mounts have been changed now & it still does it, its like the lower engine mount & the nearside mount are too soft or knackered, there all genuine items from the dealers, could it be fuel related in any way? lee
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Doggy
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Re: front end jolt

Post by Doggy »

It's possible to install the bottom engine mount bush in the wrong orientation - the rubber 'doughnut' has two spaces which have to be aligned with the way the engine's supposed to be able to move, (can't remember the right way tho). :oops: :cry:
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sym
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Re: front end jolt

Post by sym »

Doggy wrote:It's possible to install the bottom engine mount bush in the wrong orientation - the rubber 'doughnut' has two spaces which have to be aligned with the way the engine's supposed to be able to move, (can't remember the right way tho). :oops: :cry:
i had that one done at a garage as ive no way of doing it, the only way would be to get it replaced again & put it in different to the way it is now, il have a look at some pics of the bottom mount & compare mine, thanks, lee
keppler
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Re: front end jolt

Post by keppler »

sym wrote:
Doggy wrote:It's possible to install the bottom engine mount bush in the wrong orientation - the rubber 'doughnut' has two spaces which have to be aligned with the way the engine's supposed to be able to move, (can't remember the right way tho). :oops: :cry:
i had that one done at a garage as ive no way of doing it, the only way would be to get it replaced again & put it in different to the way it is now, il have a look at some pics of the bottom mount & compare mine, thanks, lee
Hi sym, Doggy's right,
the solid parts of the bottom engine mounting should be vertical and the gaps should be at the horizontal so when the engine tries to pivot on the upper mounts there is some movement allowed.
sym
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Re: front end jolt

Post by sym »

keppler wrote:
sym wrote:
Doggy wrote:It's possible to install the bottom engine mount bush in the wrong orientation - the rubber 'doughnut' has two spaces which have to be aligned with the way the engine's supposed to be able to move, (can't remember the right way tho). :oops: :cry:
i had that one done at a garage as ive no way of doing it, the only way would be to get it replaced again & put it in different to the way it is now, il have a look at some pics of the bottom mount & compare mine, thanks, lee
Hi sym, Doggy's right,
the solid parts of the bottom engine mounting should be vertical and the gaps should be at the horizontal so when the engine tries to pivot on the upper mounts there is some movement allowed.
thats how its fitted, ive decided to poly bush it, ive had enough banging of the engine now, its driving me round the twist. im prepared to take a chance on engine vibration. il let you know the out come, cheers lee
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