buzzy vibration at around 1600 rpm

[EHVS]

Hi folks, I just bought a vz wagon - its the basic one, 175kw 4sp auto.

It has a buzzy/rattle vibration thing when under some load which peaks at about 1600rpm. It is noticeable up to just under 2000rpm. It's not there above 2000 and below 1500. It seems to be coming from the left side (while driving) of the engine bay.

I haven't done any analysis yet, as I keep forgetting until I drive it. I don't think it happens while stationary and simply revving.

I'll have a go stationary tomorrow morning to see if it happens. I've just changed the oil and the oil&air filters.

Anyone have a clue/experience as to what may be causing such a thing?

 

[EHVS]

Further info. It doesn't do it while in park. I removed the plastic engine covers and radiator cover, no change.

 

[SavVYute]

Anything loosely mounted on the firewall? Clips etc.
Lower down it might be the exhaust heat shields or a clamp loose.

 

[EHVS]

Thx for the input savvy. I've had a quick look now and there doesn't seem to be anything loose. The heatshields are pretty tight. I don't think they would cause the vibration though, perhaps the buzzy resonance. The vibes can be felt in the cabin.

 

[GetToDaChopa]

I get a buzzy noise on my exhaust from the heat shield even though it's all tight.

 

[SavVYute]

Ok. If it's happening while you're cruising you might have a misfire from a faulty coil breaking down under load.

 

[EHVS]

I tried unplugging each coil and seemed to get a relative effect on each coil. As you say, it could be faulty and breaking down under load. Is there a way to check/test for this?
Other thought I've had is it could be engine or gearbox mounts which I don't really know how to check for. Tried rocking the engine by hand but it's pretty solid.

I had meant to check/change the plugs on purchasing the vehicle only to discover that it is some effort to do so, compared to the VS anyway.

 

[Stubacha]

Did you ever get to the bottom of this problem

 

[Stubacha]

i found the problem with mine the AC compressor was slightly loose put it in drive foot on the brake and get in the rev range whilst someone puts a little pressure on the ac hose and see if the vibration stops

Did you ever get to the bottom of this problem

 

[diysv6]

Some members have reported a vibration/rubbing point where the solid AC lines are fed through the firewall.

Maybe you have a rubbing issue causing the vibration?