The 75 and ZT Owners Club Forums - View Single Post - KV6 bad engine noise & vibration - looks like I may need to take my car to a garage

Bolin · 7th September 2013, 16:07

OK, done a fair bit since I last posted.

Cam covers, breather hoses & throttle body have been cleaned. Replacement inlet manifold has been fitted after being cleaned inside, a new aux idler fitted and new cam cover oil meshs.

Car seems noticeably quieter - largely due to the inlet manifold I suspect. However, the vibration is still there, at it's worst at about 1,100rpm (ish), plus the 'third noise' mentioned in post 36, which is now very noticeable - perhaps eliminating the other louder noises has made this more prominent.

The vibration felt worse when the revs were dropping back at they drop back more slowly than I was revving it up, so they spend time around the RPM where the vibration is at its worst.

I have done more recordings. First one - from cold.
https://picasaweb.google.com/1090441...04393873218322

I then stopped recording, revved the engine and the remaining bad noise went away for a little bit, only to come back. So I did another clip where I revved the car and you can hear the noise disappearing and then coming back. N.B. the volume seems to vary a bit, seems to be due to my phone.
https://picasaweb.google.com/1090441...04394944916386

Third clip - done with aux belt disconnected. Not really any different.
https://picasaweb.google.com/1090441...04396039547394

I'm still thinking that the crank pulley damper is the cause of this..........

7th September 2013, 16:07	#42
Bolin This is my second home Rover 75 2.5 V6 Connoisseur SE 4dr manual Wedgewood Blue 2 04-05/06/2001 Join Date: Nov 2006 Location: N.E. Hampshire Posts: 4,617 Thanks: 289 Thanked 308 Times in 243 Posts	OK, done a fair bit since I last posted. Cam covers, breather hoses & throttle body have been cleaned. Replacement inlet manifold has been fitted after being cleaned inside, a new aux idler fitted and new cam cover oil meshs. Car seems noticeably quieter - largely due to the inlet manifold I suspect. However, the vibration is still there, at it's worst at about 1,100rpm (ish), plus the 'third noise' mentioned in post 36, which is now very noticeable - perhaps eliminating the other louder noises has made this more prominent. The vibration felt worse when the revs were dropping back at they drop back more slowly than I was revving it up, so they spend time around the RPM where the vibration is at its worst. I have done more recordings. First one - from cold. https://picasaweb.google.com/1090441...04393873218322 I then stopped recording, revved the engine and the remaining bad noise went away for a little bit, only to come back. So I did another clip where I revved the car and you can hear the noise disappearing and then coming back. N.B. the volume seems to vary a bit, seems to be due to my phone. https://picasaweb.google.com/1090441...04394944916386 Third clip - done with aux belt disconnected. Not really any different. https://picasaweb.google.com/1090441...04396039547394 I'm still thinking that the crank pulley damper is the cause of this.......... __________________ "...the new Rover 75, which is a fabulous car......I think it looks fabulous....It's like sitting in a Rolls Royce......For me, this is the star of the show.....it looks so good" - J. Clarkson, motoring journalist on the launch of the Rover 75 in 1998.