Vibration, grinding rumble in my VF 6.0 auto when feathering throttle or using cruise control. At any speed.

[Momby]

If it’s a factory tune, then issues of square wave stutter (not sure what that is to be honest) isn’t something a dealer can fix… All a dealer can do is check to see if GM/Holden have an updated factory tune showing on GDS2 against the owners car (VIN)… If it’s an after market engine tune, then OP needs to go back to the tuner for them to look at it (if that is where the issue lies).

As to dirty jets, it ain’t a carbi engined VF but I assume you mean partly blocked injectors or poor spray pattern… Maybe it’s bad fuel or may be it’s the own faulty injector issue. Always worth running some injector cleaner when you have a low tank of fuel as a first fix, then filling up with some good fuel when you are almost empty. See how that goes over the next tank…

If it’s the known injector issues that plagues some VF’s, the easiest check for faulty injectors is to look for any misfire trouble codes and/or check injector resistance as dodgy injectors would be rather different to good injector tors (can’t remember the ohms)… If misfire DTC’s are showing and injector resistance is wrong, Holden has replaced all injectors when such occurs but who knows if they will do the same now (with their don’t give a shot attitude).

BUT, I thought this known injector issue was on the 6.2 ltr LS3 V8 and not on the earlier 6.0 ltr L77 V8. Interestingly the OP lists VF in thread title and VE in their ride so it’s unclear which vehicle it is that has the problem, VE or early VF?

Regardless, the dealer that did the auto job should have checked things out fully when Tne vibration issue was raised and not just fobbed the owner off saying such vibrations that didn’t exist before are normal. pulling yne auto to change TQ and doing who knows what else does have scope for careless fcukups

Wow, maybe a bit much for me to comprehend but will someone I think maybe able to decipher for me.
Thank very very much for taking so much time on this, it's very much appreciated.
Cheers.

 

[UTE042_NZ]

Like farked injectors?

Or just dirty as?
V. hard to diagnose over the internet with no information.
KMs, owned from new or recent 10th owner, service history (dealer regular always or self mostly sometimes), unmolested or seriously tamperered with (absolutlely stock or mail-order chip chip installed by an ex-mate) usage (daily or weekly, long commutes or lots of short stop start cold runs), drive like you stole it or like a grandma?

Momby asked any ideas. Square wave stutter was one I made up on the spot, so sue me.

I'd shove a bottle of injector cleaner in the tank and then put a full tank of 98 on top of it (real stuff - non of that ethanol shite in it) and drive it aggressively for an hour each way at 100 kph. That's 2 hours at least. Might just need a good drink and a clean out. Then again the stress might just kill it.

 

[Momby]

Or just dirty as?
V. hard to diagnose over the internet with no information.
KMs, owned from new or recent 10th owner, service history (dealer regular always or self mostly sometimes), unmolested or seriously tamperered with (absolutlely stock or mail-order chip chip installed by an ex-mate) usage (daily or weekly, long commutes or lots of short stop start cold runs), drive like you stole it or like a grandma?

Momby asked any ideas. Square wave stutter was one I made up on the spot, so sue me.

I'd shove a bottle of injector cleaner in the tank and then put a full tank of 98 on top of it (real stuff - non of that ethanol shite in it) and drive it aggressively for an hour each way at 100 kph. That's 2 hours at least. Might just need a good drink and a clean out. Then again the stress might just kill it.

Hahaha, yes get it totally.
It's 2014 Calais V done 65ks when I bought it 3 mths ago. Totally stock, perfect Dealer service history. I'm 73, so driven like a grandma 90% of the time because it's my baby, however I do like to hook into it every now and then. I still have an identical VE Series 11 In my garage that I bought 4 years ago which had done 65ks at the time now 111ks, never had an ounce of trouble, babied 90% of the time as well.
I am guilty of using E10 petrol 100% of the time in both. Acknowledge that could be an issue, but doubt it's the problem.
I'm no mechanic, but did spend 40 odd years in the car game, 20 as a GM, for a large Mitsu dealership in Sydney, the later 5 as a wholesale manager, valuer, buyer, so have bought quite possibly more than a 1000 cars in that time. I do know a good car when I see one.
This one obviously, got the better of me. As someone said, S*it happens.
Thanks again for your input.

 

[Skylarking]

I am guilty of using E10 petrol 100% of the time in both. Acknowledge that could be an issue, but doubt it's the problem.

Ah, if the car has had a life on 95 or 98 and has also spent time sitting for long periods, a small amount of varnish can build up in the tank and lines. Then if you as a new owner chuck in a tank of e10, it can loosen the years of fine varnish in the fuel system and cause part blockages of injectors. Good thing is to throw in more fresh e10 or even e85 if the car is capable as ethanol (especially the higher amounts in e85) will wash things clean…

Having said that, if you didn’t have a problem b4 the TQ change, doubt that’s your issue. And injector issues or bad fuel almost always cause P030x error codes

 

[Momby]

Ah, if the car has had a life on 95 or 98 and has also spent time sitting for long periods, a small amount of varnish can build up in the tank and lines. Then if you as a new owner chuck in a tank of e10, it can loosen the years of fine varnish in the fuel system and cause part blockages of injectors. Good thing is to throw in more fresh e10 or even e85 if the car is capable as ethanol (especially the higher amounts in e85) will wash things clean…

Having said that, if you didn’t have a problem b4 the TQ change, doubt that’s your issue. And injector issues or bad fuel almost always cause P030x error codes

Not sure what you mean by TQ change?
After apparently fitting new torque converter and harmonic balancer selling dealership referred me to local GM, service how said, vibration is STD, nothing wrong here, saying they tested 3 or 4 other VF's in for service, all displayed the same issue, I find that hard to believe.
The only error code I've had displayed in the 3 months and 4000ks I've owned the car is "check steering wheel lock" or something to that effect, displayed maybe 3 or 4 times, then not evident after restarting the car. Given it doesn't have a steering lock, I haven't worried too much about it.

 

[Skylarking]

TQ … meant TC = torque converter though I use them intercaphangably

 

[Momby]

TQ … meant TC = torque converter though I use them intercaphangably

 

[Momby]

Thanks

 

[Anthony121]

I think my Redline does the same thing. It's noticeable around 80-90 kms per hour after you place your foot back on the throttle after coasting. It's a slight rumble as if the car is coming back to life. Maybe it the tailshaft taking the slack back up after coasting. I haven't noticed it in the Director. Also the SS also has a 2.5 mid section and maybe the engine firing back up too as I think sometimes the spark and fuel is cut while coasting.


I'll add maybe it's a harmonic thing within the car. It doesn't seem to be tyres as they have been changed and I put it down to tail shaft taking up the slack again when throttle is pushed.

 

[Momby]

I think my Redline does the same thing. It's noticeable around 80-90 kms per hour after you place your foot back on the throttle after coasting. It's a slight rumble as if the car is coming back to life. Maybe it the tailshaft taking the slack back up after coasting. I haven't noticed it in the Director. Also the SS also has a 2.5 mid section and maybe the engine firing back up too as I think sometimes the spark and fuel is cut while coasting.


I'll add maybe it's a harmonic thing within the car. It doesn't seem to be tyres as they have been changed and I put it down to tail shaft taking up the slack again when throttle is pushed.

Thanks Anthony for your thoughts. That does seem to be the same or very similar issue.
I called into a performance workshop today specialising in among other things Commodores, after explaining my lengthy story including the fact my series 2 VE doesn't display this problem, BUT, that I'd be running both on E10 fuel, his diagnosis was the fuel, some kind of fuel or octane module/sensor that's in the VF, but not in the VE. So his thoughts, run tank basically dry and fill with 98, I'm going to give it a try and will only use 98 in the future.
Thanks again for touching base, Cheers.