Massive vibrations at low rpm, Engine feeling loose

[Ex-User (107751)]

Hi
I'm getting very strong and loud vibrations when driving less than 900 rpm. If I floor it at 4/5 gear at low speed, I can feel and hear the engine and gearbox banging forward and backwards very hard.
Also I'm getting a loud "bang" noise when releasing the clutch between gears (normally, not quickly) , unless I take 2-3 seconds to release it very smoothly. Also If I play with the throttle at fifth gear (say 60mph) it feels and sounds like the engine is moving a lot.
All 4 mounts were changed , Tried to release all the mounts and re-tigthen them in a few different positions (engine as forward as possible etc), no changes.
I'm using a powerflex dogbone since getting the car, powerflex replaced it for me and it didn't help. Maybe this is the cause, but I'm having a hard time believing no one wrote about this online if the powerflex mount was the cause.
What else could cause this ?

 

[barnesautos]

Sounds like your engine mounts are weak or sunk and it causing the down pipe to hit the heat shield on the subframe .

If the mounts have been changed then check for hoses touching ect near the bulkhead area

 

[Ex-User (107751)]

3 new oem mounts from ktec and powerflex dogbone...
The vibrations are very harsh, not something like hoses not in place.

 

[DannyR]

Checked the mount bolts? Could of forgot to tighten some if only just fitted maybe?

Especially dogbone

 

[Ex-User (107751)]

I wish, I reinstalled the mounts a few times already to try and solve this... :tongueclosed:

 

[DannyR]

Possibly driveshafts?

 

[Ex-User (107751)]

Turning left or right at full lock, with any throttle amount, doesn't make any special ticking noise. Does this rule out driveshafts? Or only CV joints ?

 

[bozothenutter]

loosen up the engine mounts, let the engine run and find it's 'spot' then tighten it all up again.

 

[Ex-User (107751)]

That's what I did a few times, also tried tigthening them when someone is holding the clutch on first gear and reverse for a few seconds, using a jack to get the engine as forward as possible, nothing have any effect on this.... But some positions do make gear shifts much better.

 

[bozothenutter]

just thought of something.
Is the bolt on top of the gearbox still in one piece?
Mine broke off and it didn't really show until I removed the mount to have a look.
It is the bolt that sticks up from tha tripod that is attached to the gearbox.

 

[Ex-User (107751)]

Yeah it's ok. I bought a generic dogbone to make sure it isn't the powerflex, still crazy vibrations at low RPMs.