Thread: How smooth is your 3.0 at idle?

My D4 was smooth as initially but I've noticed it getting slowly rougher at ideal especially when stopped and in drive. The vehicle only has 5k on it so at this stage I'm putting it down to the engine loosing up and the idle speed increasing although I would have thought it was electronically fixed. It's due for it's health check so I'll see how it comes back from that.

Coming up to 26,000km on the clock for my Sep 11 D4 3.0L. It runs well, is quiet, with no noticable roughness. It has also had a software update at 13,500km. The only noticable difference after that was (in my opinion) an improvement in the auto-trans gear changes.

Originally Posted by Graeme

I noticed an engine-related harshness at idle when I started the D4 at the dealers after open heart surgery but perhaps all the 3.0 engines are like this.

Hi Graeme, I know a few people that have the 3.0 Lt engines including myself. No complaints so far, in fact one bloke I know has clocked over 240,000 Klm's.

Cheers, Craig

Hi Graeme
My 3lt (65k, 08/2009 build) has just been at dealers for a rough/miss idle,
when cold at start
if I slowly raise revs,. at 1100 rpm it is most noticable.
Dealer did reproduce, and has sent enquiry to LRA.
Will let you know what they say


Cheers Ken

Thanks Ken. I only checked slightly higher revs so will do some more checking. I don't think the roughness is only when cold but will monitor that too. It may be that the engine has had this roughness all the while but that there is now a misplaced hose or something else after the body lift that is transmitting the roughness to the body, although I think the roughness shouldn't exist anyway. Having the harmonic balancer moving at the same time on such a new and modern engine makes me nervous too, especially as its purpose is usually to smooth harmonics created by the addition of ancilliary equipment at higher revs, not the engine itself. I thought the Faultmate might show injector information but not so. Warranty is running out with 80K on the clock so there's some urgency in getting it resolved.

Hi Graeme
A follow up on rough idle, mine was rough at about 1100 rpm, more noticable when cold, but still there when warm in the end run.
LRA wanted dealer to do live data test and send to them.
Came back with everything OK with engine, must be a vibration from somewhere.
Dealer has been over it with electronic ear, and reckons it is an ordinary engine mount.
They get replaced tomorrow, will see then

Cheers Ken

I discovered on Monday whilst using CC at 110 kph up a rather steep incline on the freeway that the vibration was considerably worse, to the extent that the vibration through the steering wheel made all my fingers tingle until the crest when less power was produced. I still haven't had a proper look to see if something is out of place after the body-off job but must do so before any damage is done if that is the cause. I'd be surprised if mine's cause is an engine mount as it started with the body-off job but that could be a coincidence.

Bloody hell......that does not sound good Graeme.

Looks as though someone has certainly not put the body back on correctly.

Brett......