MASSIVE Engine Vibration When Idling.

[SammyLe]

Hi guys,

Anyone ever come across an engine that vibrates violently when idling and then worse again when just a little throttle is engaged (Anything past around 1100 Revs seems fine). I have a 2001 2.0 Hdi 90. 143,000 miles.

My knowledge of cars is incredibly limited but been trying to rule out any obvious causes. I'd read that some injectors may not be firing properly at low revs, but I wacked a screwdriver on each injector base and put my ear to it... All seem to be firing consistently, and checked the impedance across the contacts which are all holding steady at 1 Ohm. (I'm assuming that's the correct impedance, they're all the same!)

I've also had a look at the stay bar which seems to fine.

My next, and seemingly most obvious thought is worn engine mounts. I can see the bushing on the passenger side, above the gearbox, moving like jelly and a little of the same on the lower-rear engine "dog bone" mount. I wasn't sure whether this was happening because the bushings are compensating for a deeper problem, or if they are the problem. I've felt them and visual inspected them but I don't know exactly how solid one of these bushings is supposed to feel. From what I've been reading, engines with dead mounts tend to shudder and clunk specifically on starts, stops and gear changes? Mine isn't doing any of this, even going from "full wobble" to higher revs the engine just seems to settle with a gentle transition rather than wrenching itself around the engine bay.

Is there anything else it could be? I just need to track down the problem for definite, made so many misdiagnosed repairs to my previous car which cost a fortune and it still died of "unknown causes"... Rather avoid that again.

Seen a lot of forum posts (everywhere) where barely any details are posted so I've tried to be as thorough as possible. Any help would be greatly appreciated.

Cheersen!

[rwb]

Hi & welcome,

Engine mounts certainly seem like a likely culprit.

With the engine off, grab it by the rocker cover and try to rock it forwards and backwards. If you can move it at all then the mounts are shot.

When they were shot on my 90 the most noticeable thing was shuddering when trying to pull from low revs, e.g., applying gentle (but not heavy) throttle from 1100 in 4th.

And change with the clutch in/out?

[annie10]

rear engine mounts like cause. i did mine on my 406 90hp and on my xsara piccaso and a simpleish job if you are used to spanners . i got all the help on here and it made all the difference to my confidence in doing the job. on the 406 it took two hrs but i couldn't get the wheel hub nut off so had to drop the suspension and get it out that way.