wampir

Hi guys.
I have a question. When my car is on idle it gets big vibrations. Anyone know what could be wrong?
I tried to search on this forum, but my mechanic checked everything people written about it - engine mounts are changed (used, but in good shape and original, mine was worn), balance is checked, idle is on 1k rpm, compression is good (9.5-10 bar), changed spark plugs with distributor cap and rotor, ignition leads with plugs (everything new) - and still getting those vibrations.
Can anyone help what else could i check?

MPD47

One of the balance shafts 180 degrees out?

wampir

Dont know if i understand this right. You say that balance shaft may be set up incorrectly? It was checked and set correctly, so it should be ok. Or should it be replaced?

MPD47

Yeah you got it, I was checking to see if it was aligned correctly.

Does it vibrate through the RPM range or just at idle?

wampir

Its from idle to about 1100-1200 rpm (tried to slowly increase rpm to get the point where vibrations stops but its hard to tell exactly) - so you can tell that on idle only. On higher rpms everything is okay.

MPD47

Hmmm, I'm fresh out of ideas, but it is 6am, I haven't slept, and have a full day ahead of me.

How badly is it vibrating?

spoolin51

Mike can't injectors cause bad idle?

wampir

How badly? How should i define that? Whole car is shaking. When you sit inside you can see the shifter shaking. It isnt that much so it could make me any problems (didnt even noticed that its something wrong, before my mechanic didnt say that it shouldnt be this way but still its vibrating and it shouldnt so im trying to find where the problem is.
Im starting to think that somebody setup something incorrectly in the engine, but dont know what it could be. And we are also out of ideas

MPD47

Iratic idle from faulty injectors? Sure, but that doesn't sound like the cause IMO.

Chris White

USED motor mounts......I would look at those first! Don't even think about the cheap new ones either - they don't last a year in most cases.
Typically balance shaft problems are most noteabel at about 3400 rpm.

wampir

Though of that, but mine were completely damaged, we changed to another set of used ones - but in good condition and it almost didnt change anything, thats why i think that its not a problem with engine mounts.
And the new ones costs about 200 eu for 1 So would like to know that i really need new ones before i throw 400 eu for nothing...

Chris White

Yeah, I hate throwing money at a problem unless you know what the problem is!
How do you know that the used mounts were good? If they were original they were filled with a fluid that usually leaks out – so they may have looked good but aren’t. The best way is to look at the installed height – that will tell you if they are compressed.
Its possible that a misfire is causing the vibration – but if idle speed is good and the engine is not visibly shaking then motor mounts are a good guess.

wampir

How to check that?

Idle speed is good, but dont know if the engine is visibly shaking. Didnt think of checking that.

wampir

Ok, im going to get another set of engine mounts and check if it will be better. Ill let you know

ehall

You could also have a reference sensor that is just a bit out of spec, or not tight enough. I know for certain that is the problem with mine, I just haven't fixed it yet.