Hi all,
I know a fair bit about VL's etc.. but not much about the V6's so to speak.
I have a stock VR that has a nice annoying rattle! It really sounds like a heat fender rattling off the exhaust (which it is not) but sounds dead set like that! It rattles in all gears including idle at low revs. Once the revs pick up, it goes. I first thought it was coming from the auto, but after pulling down the inspection plate etc. All the bolts were tight and no cracks on the plate. Then, I was actually changing oil back to the standard 20/50 after having a thinner grade in it and noticed that the rattle is a little quieter when cold, but, reverts to the same old noise when warm, hence, why I am now convinced it is from the engine.
I mean I have spoken to a few gear box mobs who all say it is not the box and one went further to say that the V6's sometimes had some rattle for some anti balance device on the crank???
Like I said, I have no idea about the V6's but have heard at least 3 others on the road with the identical rattle, leading me to believe that this may have been raised here before?
Any help would be greatly appreciated!!
Cheers Guy's!
Yeah thank's dude!
Yeah, something to do with the anti balance.... I think though a whole lot of mucking around... Might as well just get a reco replacement! Bloddy things....
Quote:
Originally Posted by aus880
Welcome back
That engine rattle is common in the V6s
I've heard that there is a balance shaft that you can simply disconnect and that shuts them up.
The rattle is caused by the crappy link timing chain which stretches,this then flops around and makes the noise (even though there is a tensioner which is suppposed to stop this).
I have rebuilt 2 Holden V6's which have had this problem and a good brand timing chain like a Crow single row roller chain has fixed this problem,also fit a new tensioner as these become brittle with age and can fall apart after removal..
Never remove the balance shaft in a road car as this will cause the motor to hit the sides of the strut towers (literally),I was told that this happens when the balance shaft is removed.
Quote:
Originally Posted by aus880
I've replaced a timing chain in a V6 and it made no difference to the noise.
Was that a link or roller timing chain?
The V6's I rebuilt ran as quiet as a mouse (apart from when headers and the mandrel bent exhaust systems were fitted,this made the exhaust loud) after the motors were fully rebuilt,that is replacing the timing chain set with a good quality aftermarket "roller" chain & sprockets,along with a new tensioner.
THe balance shaft bearing up the front, if they start collapsing from excessive wear this will make the motor noisy also.
I know an engine builder (who is semi retired) who had the trouble with the old Falcon 250 Xflow motors where he'd fit a link chain into a recoed motor,a lap around the block resulted in a rattle from the front of the motor,then off came the timing cover then a new roller chain was then fitted,the SOHC Falcon motors also use a link chain.
Note these V6 engines that I rebuilt had done 300,000 - 500,000 kms ,the last one we wanted to make sure was o.k. as it has a knocking noise in it and a piece of bearing (big end bearing) came out in the oil,so the piston to bore clearance was checked along with the bearing clearances,the motor apeared to be wearing the original oil filter (GM filter) so not surprisingly the clearances were out of spec or at the edge with both bore clearance & bearing clearance.
THe block was bored out 20 thou oversized but the crank was left alone till we could check the clearance with new shells using a plastigauge,this resulted in the clearanced being at the bottom to middle of specs,it was the same case with the new pistons as the clearance was also in the middle after the rebore.
The cam bearings were also replaced and line honed to suit the new cam journal diameter.
