VN S1 Rattle

[JoshSvc]

Okay guys, i've had the VN S1 V6 for about 6 months now and she is having afew issues.

Small engine knock that rises and falls with revs.
Rattle like marbles in a can, more so when in Drive and when under load - But not when the engine is cold when its cold of a morning it has no noise at all.
Vibration when the car hits 80kph which i'm assuming is the infamous torque converter lock up so it will need to be replaced.

Engine has been serviced, transmission oil is a bright red i havent serviced it yet as the torque converter has to come out and be replaced and i didnt want to service it if there is crap in the converter.

I'm thinking a damaged rod is causing the knock so the engine is up for a rebuild and the transmission either needs a full service or replacing as well, i would happily convert it to a 5 speed manual but i plan on using the car for towing.

Any other ideas?

 

[delcowizzid]

the s1 engines are bad for smashing off the timing chain tensioner and rattling like hell

 

[JoshSvc]

Sorry i forgot to put that in there to, it does sound like a chain related noise i mean i hear every second vn-vr commodore making the same noise, the rattle i can fix but the engine knock is abit more worrying.

 

[someguy360]

probably balancer shaft......pretty common (If the S1 had a balancer shaft, can't remember)

 

[1991VNvacationer]

probably balancer shaft......pretty common (If the S1 had a balancer shaft, can't remember)

They did have a balance shaft, and it could be the bearings. I don't think it would rod knock, but I would guess that its either timing chain or bearings.

 

[Jxfwsf]

probably balancer shaft......pretty common (If the S1 had a balancer shaft, can't remember)

All v6's have the balance shaft (In holdens anyway), something about bolting a couple of 3 cylinders together equates to a very unevenly balanced platform... but it'll either be a shagged front blance shaft bearing as you said (6205-N partnumber and must have the ring groove in the outer shell, apparently running this type of bearing with a helical cut gear driving it wasn't the best idea... but hey it's probably lasted 400,000km's so it ain't to bad) or more commonly the chain tensioner is in the sump, the timing chain has stretched, it's never been changed and is flapping around in the wind like.... well iono, whatever flaps about in the wind unrestricted alot....

 

[JoshSvc]

Okay i'll look into the timing chain and also the balance shaft, i have a set of inlet manifold gaskets here as well, i kind of dont want to start replacing things until i can pin point this knock, lets see if the tensioner is still intact and go from there.

 

[HarryHoudini]

The harmonic balancer can get a knock that resonates in other parts of the motor before it finally sheets itself.