This Engine Mount Knocking!

[woody_159_2000]

There seems to be a fair few of these threads, so I hope this is slightly different!

I get a rocking/ knocking/rattling type noise when accelerating briskly in 1st and 2nd sometimes 3rd. This noise also happens when driving across really uneven roads.

I don't know if this is related or just a coincidence but the noise started after I went over a speed bump that had a chunk out the front of it so it was almost like driving up a curb!

Any help and ideas as to the cause of the Noise is much appreciated, cheers

 

[Budgie]

Check all the mounts are tight and not visibly shot.

If not, undo mounts, pull engine forward and tighten mounts whilst it's still forward. THe noise you can probably hear is the manifold knocking on the subframe.

 

[DMS]

The engine will rock about if the dogbone mount bush is knackered too.
It's one of the things my car's having replaced this week to sort the exact same problem.

 

[woody_159_2000]

Not sure how to check the dog bone mount bushes. But the upper engine mount above the cambelt does show some signs of movement.

The rubber wedges around the middle part appear to have been rubbing against the solid black square surround part (sorry for lack of technical names)

Red areas



Cause for concern or normal? How do i check the other mounts? (not my car, just for illustravtive purpose)

Thanks

 

[Cookson]

I was thinking of fabbing up a shim to bolt down onto that and slip 2 x metal pieces inbetween the rubbers, like a wedge

 

[DMS]

The dog bone mount is beneath the car. It's quite hard to miss - it connects to the gearbox and has a twist in it. The bushes are the pieces of rubber attached to either end of it. If they look worn it may be time to replace them (quite cheap).
I don't know how you'd check the top mounts for movement. Perhaps try rocking the engine while the car is stationary?

 

[woody_159_2000]

Cookson how did you do that? and did it work?

 

[woody_159_2000]

The dog bone mount is beneath the car. It's quite hard to miss - it connects to the gearbox and has a twist in it. The bushes are the pieces of rubber attached to either end of it. If they look worn it may be time to replace them (quite cheap).
I don't know how you'd check the top mounts for movement. Perhaps try rocking the engine while the car is stationary?

Thats how i checked the mount above the cambelt, it moved a bit, just over half a centimetre. Wheres the other top mount?

 

[Cookson]

Cookson how did you do that? and did it work?

Thinking of doing it, lol

Would just be a case of measuring, cutting, and bending some steel into like an M shape, but flat in the middle, for the bolt

 

[franx]

^^ I also tried this.. simple, two 3mm plates grinded into wedge shape so you could fill the two gaps.

Test-drove it around for 2 hours and removed the shims (plates) ; did'nt like it. Tightening up the engine (stopping movement) on just one side made my car feel like it had a sort of pull to one side when hitting the throttle, a sort of torque steer. When thinking about it it's logical that it did this. Throttle coming to one of the wheels sooner/harder because of just the one side stiffened up.

It would work when also doing the gearboxmount under the battery

 

[franx]

Not sure how to check the dog bone mount bushes. But the upper engine mount above the cambelt does show some signs of movement.

The rubber wedges around the middle part appear to have been rubbing against the solid black square surround part (sorry for lack of technical names)

Red areas

View attachment 41811

Cause for concern or normal? How do i check the other mounts? (not my car, just for illustravtive purpose)

Thanks

The mount is supposed two allow this movement. (little gaps) Sucks, but it's normal do'nt worry

 

[woody_159_2000]

So i can rule out this mount as the cause...Just got to check the other one under battery and dogbone bushes.

Anything else i need to look out for?

 

[franx]

a mount can actually be broken.. even the one we were talking about , without being able to see it from above when looking at it.
Pop open the hood and grab your engine by the inlet and pull hard forward and backward. The engine should only have "some" movement, say 2 to 3 centimeters (between back + forth)

 

[woody_159_2000]

a mount can actually be broken.. even the one we were talking about , without being able to see it from above when looking at it.
Pop open the hood and grab your engine by the inlet and pull hard forward and backward. The engine should only have "some" movement, say 2 to 3 centimeters (between back + forth)

I have done that, i get movement of max 1cm back and forth (no im not being weak) before the whole car rocks about. so i guess/hope that its not broken.

 

[ianysm]

Its most likely to be th edogbone mount underneath. Having mine changed this week also. I ordered the powerflex one form KAM racing. £34 delivered. Apparently quite easy to fit. I looked under the car at this mount with engine running and its obvious how much engine movement this one controls even just at tickover.

The garage also found a bracket that was not tight and pretruding onto the engine/manifold causing nasty grinding sound at slow speeds.

All covered by the warranty luckily but non of it is expensive stuff