Now I'm Sure Its Not Big Ends Rattling

[kyepan 291]

Short version, I think its an engine mount.. but am not sure.

 

 

long version, car was running fine, went round a long left hander (m25 to m40 north bound slip road) took it easy, low revs but about 60, pressure dropped as it usually does, backed off.

Pooteled back down the broads to maidenhead from beaconsfield, got to the bottom, noticed it was sounding horse when decelerating towards some lights, alot of vibration was being transmitted through the cabin at about 3000 - 4000 rpm. It pulls cleanly, and rev's smoothly, the noise definilty is only around the 3-4k. out of gear it still happens, with clutch depressed it still happens. It was low on oil but i've topped it right up, not much has improved noise wise though.

 

Got the old mans ears out, and he's 100% sure its not big ends, he thraped it about for 20 mins untill i told him he was just doing it for fun, then said its transmitted vibration.

 

I've got a solid lower engine mount, with very little movement so its not the exaust fouling on the subframe cross member, or the bulk head, the exaust is tight, all the manifold stud nuts are ok, as are the clamps for each section. checked for play in the lower engine mount, the upper one is resting on the rear most rubber and will move about 7mm when you rock the engine, is that normal?

 

The upper left mount and gearbox mount have never been replaced though, what symptoms would they exhibit when going.

 

any replies appreciated.

 

cheers

 

J

[ashley peddle 3]

7mm is quite a lot of movement so i would get that sorted as a matter of course... iv always had 0mm movement but 1 or 2 at the most for road cars i would have thought?

[Tom Fenton 1,526]

As above it does sound a tad excessive. As a test, open the bonnet, with the engine running, and get your dad/mate to just take up drive on the clutch in 1st with the handbrake on, the engine will move a little, but if the whole lot is flopping about then perhaps a new mount is needed.

 

The other possibility is a knackered driveshaft inner CV causing this vibration, I've had this a couple of times now, on a 205 it was the inner joint on the long shaft near the intermediate bearing, on a 306 it was the short shaft inner CV u/s.

 

Hope that helps.

[McPikie 0]

The other possibility is a knackered driveshaft inner CV causing this vibration, I've had this a couple of times now, on a 205 it was the inner joint on the long shaft near the intermediate bearing, on a 306 it was the short shaft inner CV u/s.

 

Hope that helps.

Seconded

 

Had this issue myself and now having to do the otherside

[kyepan 291]

As above it does sound a tad excessive. As a test, open the bonnet, with the engine running, and get your dad/mate to just take up drive on the clutch in 1st with the handbrake on, the engine will move a little, but if the whole lot is flopping about then perhaps a new mount is needed.

 

The other possibility is a knackered driveshaft inner CV causing this vibration, I've had this a couple of times now, on a 205 it was the inner joint on the long shaft near the intermediate bearing, on a 306 it was the short shaft inner CV u/s.

 

Hope that helps.

I'll do the check on the movement, cheers for the tip.

 

I'm pretty sure its not the driveshaft, because it does it stationary on the drive.

[Guest ae86clyde]

Is this problem on an mi16 engine? If so im having the same issue!!! ive changed all bearings and it still persists

[Batfink 201]

Justin. Support the engine and whip the top mount off and check it for splits etc. Also might be worth checking the condition of the gearbox mount

[maxi 36 1 Cars]

If you only run a solid bottom mount and the rest are standard it sends strange resinations through the engine and actually causes the gearbox mounts to loosen. If only a solid bottom mount has to be fitted the gearbox bolts should be threadlocked in. Might be worth checking these while you are poking about.

 

Maxi

[McPikie 0]

I never knew that

 

Maybe that's why mine is knocking it's cock off then, lol

[kyepan 291]

the top right hand mount is shafted, so i'm in the process of changing it, but don't know how ot remove it, i would assume that you unwind it, however all my twisting force seems to do is twist the rubber, had it nearly 180 degree's before the hex bit in the top split the thread.. so any ideas how to remove it?

[Super Josh 4]

Hammer and Chisel/Screwdriver to drive it round. Then when you've slackened it enough it should unscrew easily enough.

 

 

 

Josh

[yeti-dj 7]

I had a horrible rattle from mine, at startup, when you rev'ed the engine at stand still and when you drove it..

 

Turned out to be the inner bearing on the drivers side drive shaft, it was dying and only found it after replacing every other part we could think of. Did expect it to be the drive shaft at all as rattled when the car was standing still..

 

hope this helps..

[kyepan 291]

Hammer and Chisel/Screwdriver to drive it round. Then when you've slackened it enough it should unscrew easily enough.

Josh

worked a treat tanks!

[kyepan 291]

however new engine mount has not fixed it, and the tell tale clunk when lifting has come about again. either its the gearbox mount or somehow the solid mount at the bottom has died, although i doubt that.

[Batfink 201]

i've got a spare gearbox mount kicking around j.

[kyepan 291]

the silence of no longer being in solid lower mount land is blissfull... spent the morning "taking out " the old bush from my spare rear engine mounting bracket, and persuading in the new one, swapped back into standard bush land, oh its so quiet.

 

However when warm something is definitly touching, suspecet the gearbox mount is to blame, as on inspection it had lots of movement and appears to have rotated on its mounting.

 

yes kev I do need that mount, seems we need to meet up, what you doing on the 18th of april?

 

Also, a friend told me that silver haired chaps driving mitsubishi gto twin turbos, are rather surprised when they don't leave little blue sheds behind at the lights, even when they take a rolling start advantage. This I was pleasantly surprised to hear this, and did smile to myself.