LS3 valve sound

[geoffm]

Purchased WN2 Caprice in 2018. 35000 on the clock. Valve failed about 100000. Mechanics replaced valves, LS7 lifters, new standard camshaft, new fuel injectors due to 1 failed. Valve sound has returned about 6 months later. Now 180000, driven carefully only by me. Noisy valve sounds like metal on metal knocking as before. Disappears in about 3 to 4 mins after first cold start. Does not return till next day first cold start. I am at a loss what to do. Surely a new valve can't fail so quickly. What else could it be? Any ideas appreciated.

 

[NJD-1992]

Given you describe it as a metal on metal knocking sound that goes away once warm, Its likely Piston Slap

Tonights reading for you

https://forums.justcommodores.com.a...le-on-ls3-piston-slap-engine-replaced.267349/

Also for further reading

https://forums.justcommodores.com.au/threads/seized-engine-vf-ss-ii.297163/

 

[geoffm]

Given you describe it as a metal on metal knocking sound that goes away once warm, Its likely Piston Slap

Tonights reading for you

https://forums.justcommodores.com.a...le-on-ls3-piston-slap-engine-replaced.267349/

Also for further reading

https://forums.justcommodores.com.au/threads/seized-engine-vf-ss-ii.297163/

Thank you very much for that.
Have left it overnight at mechanic and I shall let you know the outcome.
Fingers crossed.

 

[darrenj9413]

Purchased WN2 Caprice in 2018. 35000 on the clock. Valve failed about 100000. Mechanics replaced valves, LS7 lifters, new standard camshaft, new fuel injectors due to 1 failed. Valve sound has returned about 6 months later. Now 180000, driven carefully only by me. Noisy valve sounds like metal on metal knocking as before. Disappears in about 3 to 4 mins after first cold start. Does not return till next day first cold start. I am at a loss what to do. Surely a new valve can't fail so quickly. What else could it be? Any ideas appreciated.

I also have a WN2 Caprice and I find it makes a noise when cold. I liken it to an old fashioned tappet noise so it too might be valves. The cars now done 96K, about 6 months ago an injector failed but otherwise ok so far. I'm always carefull not to over rev it cold and if possible let it warm up for atleast a couple of minutes before driving. I often start it by remote control from the house before using it for this reason.
I'm hoping this does not lead to trouble for me or further trouble for you.

 

[geoffm]

I also have a WN2 Caprice and I find it makes a noise when cold. I liken it to an old fashioned tappet noise so it too might be valves. The cars now done 96K, about 6 months ago an injector failed but otherwise ok so far. I'm always carefull not to over rev it cold and if possible let it warm up for atleast a couple of minutes before driving. I often start it by remote control from the house before using it for this reason.
I'm hoping this does not lead to trouble for me or further trouble for you.

Hi Darren.
Yes it is a worry. I would suggest you take it to a mechanic and ask them to have a listen. I had to leave it overnight obviously, recently and they are no wiser, even though they did all the work. They said they will remove tappet covers at the next service to see if there is no physical issue or damage. Other than that, they will use thicker engine oil for a while to see if that quietens it down.
Will keep you posted.

 

[geoffm]

I also have a WN2 Caprice and I find it makes a noise when cold. I liken it to an old fashioned tappet noise so it too might be valves. The cars now done 96K, about 6 months ago an injector failed but otherwise ok so far. I'm always carefull not to over rev it cold and if possible let it warm up for atleast a couple of minutes before driving. I often start it by remote control from the house before using it for this reason.
I'm hoping this does not lead to trouble for me or further trouble for you.

Hi Darren.
Well my mechanic had the car overnight and listened to the ticking or knocking sound. He said it is possibly "lifter tick." One of the new ls7 lifters maybe be dirty or a little slow. So they changed the oil to 15w40 oil which I think is thicker and used 2 bottles of Nulon Lifter additive and we will see how it goes. No difference after a couple of weeks. The ticking sound lasts 3 minutes after first cold start up and sounds quite unhealthy. I suppose only time will tell as no one knows what to do now. Just to add insult to injury my power steering is now failing intermittently so another problem. Ah the joy of cars. Geoff

 

[darrenj9413]

Hi Darren.
Well my mechanic had the car overnight and listened to the ticking or knocking sound. He said it is possibly "lifter tick." One of the new ls7 lifters maybe be dirty or a little slow. So they changed the oil to 15w40 oil which I think is thicker and used 2 bottles of Nulon Lifter additive and we will see how it goes. No difference after a couple of weeks. The ticking sound lasts 3 minutes after first cold start up and sounds quite unhealthy. I suppose only time will tell as no one knows what to do now. Just to add insult to injury my power steering is now failing intermittently so another problem. Ah the joy of cars. Geoff

Thanks for your input Geoff, I hope all this doesn't lead to too many woes for you. Just lately I have noticed that the motor doesn't tick cold anymore. Like a ticking rattle sound it was. I didn't notice at first because I tend to start the car from the house and by the time I get down to the shed its already been running about five minutes. I made a point of starting it cold the other day while I was near it and no worrying sound. Its booked in for a service next month and I've asked my mechanic to listen to it while cold. I'm hoping the problem will just go away but I'm very shy of causing any serious damage to such an expensive motor. Darren

 

[Skylarking]

Other than that, they will use thicker engine oil for a while to see if that quietens it down.

Don't mean to be snarky but why doesn't your mechanics throw in a banana peel or two... that should quieten it down

Really, addresing noise by using hjeavier weight oil isn't a great strategy...

As is, if the engine needed new lifters and especially a new camshaft, I'd expect there was rotation of one of the lifters that resulted in metal to metal contact where a cam lobe was wiped. Such metal on metal results in sending metal throught the oiling system and potentially damaging other components. As such I'd expect good shop practice to be for the engine to have been pulled out, the sump removed and the internals very carefully inspected for damage and the presence of any metal particles... I'd think checking crank and cam bearings and their surfaces along with the condition of the oil pump along with checking the bore wall condition and checking for ovaling would be a minimum if you don't want to be having problems... Maybe I'm overly cautions but I'd not want to go blindly changing just cam and lifters and hope all else is ok...

Depending on what one finds in the partial teardown = what one needs to spend to fix the broken engine (which is why I guess some dont want to go too far into dchecking due to cost)...

Good luck with it and hopefully you've dodged a bullet...

 

[darrenj9413]

Thanks for your input Skylarking. My mechanic is going to service the car early March, in about two weeks, I don't use it daily so I'm not too worried. I'm not sure if I am like full on over reacting because it is not a sound thats real scary, does not sound like metal on metal. What it does sound like is a soft ticking sound the disapears after a couple of minutes. I'm hoping my mechanic has an opion on the matter. I'm actually not even sure if it was doing it right from the start when I bought the car two years ago, Its just something I started to notice. Anyway I'll see what my mechanic thinks, hes a pretty good mechanic and has a couple of V8 cars of his own, older models than we are talking about.

 

[RevNev]

Really, addresing noise by using hjeavier weight oil isn't a great strategy...

A lifter bleeding down overnight from the spring tension of an open valve, will pump up and stop rattling faster with a thinner oil. Thicker oils are only beneficial for increasing hot oil pressure from worn or excessive clearances.