Occasional ping from engine bay while driving

[savage1987]

Not sure what this is, used to do it heaps before rebuilding auto, now maybe not quite as much. Pinging noise occurs at random, not under certain load conditions etc... I have no idea why or what this is.

I don't know what detonation sounds like so have nothing to compare it to, however it happened before and after my new memcal so I don't think it's that. Is it just my motor being old? 500,000km old?

Has a tiny miss for a few seconds on cold startup shortly followed by a random flat spot but apart from that no real problems bar a massively old timing chain.

Can anyone shed any light on this for me? I don't even know where to start
Sam

[greenfoam]

I reckon if the only issue you have after 500,000 is a slight miss you count your blessings

[rawsonn]

lol so true greenfoam

[savage1987]

haha true.. but wtf is that ping? lol

also fuel efficiency has stayed EXACTLY the same (to within 10km / tank) as before your tune Jason, so I KNOW something is wrong!

[PaRaDoX]

maybe its because you dont thrash it enough?

i wouldnt be suprised if something along your timing line is slapping its way round, maybe timing chains loose? ive snapped a tensioner before left shards all in my sump, but it was also making sounds like a prostitutes business tool in action. but that was just rod knock :P

maybe your coil pack grounding is ****? that explains any missing etc

i dunno dude go over everything and check for anything dodgy, best way to figure out whats broke

[savage1987]

haha, no I'm pretty sure it really doesn't want to be thrashed.

Timing chain loose? Probably, it's VERY old. I haven't had it done. Dad never had it done. That means it hasn't been done in 15 years and 400,000km or so. Question being: do I replace it now or just keep saving and hope it holds on long enough for me to find a VP Calais?

Coil pack probably needs doing, it's still the original :0

Already checked as much as I can think of, that's why I let it go for so long (years) before posting a thread about it

[excalibur]

I reckon if the only issue you have after 500,000 is a slight miss you count your blessings

i only hope of getting that many KMs out of my VP with no probs like yours

[savage1987]

I rebuilt the auto a few months back, but not sure that counts ..

[savage1987]

Sounds like stones flicking up and hitting metal.... or metal expanding/contracting with heat...

Nobody?

[Bz Kn33z]

take a recording of it, it might help some people diagnose it where do u think the sound is coming from, the timing chain is most likly stuffed and streched and the tensioner is most likly rooted.

[vnv8driver]

Might not be a ping, can be hard to hear over a buick!

Are you running 95 RON fuel?

[savage1987]

Might start with timing chain..
Sound seems to be coming from the bottom of the engine bay somewhere, on the driver's side.. sounds that way while driving anyway. At first I thought it was rocks hitting my inner guard, but then I realised they're plastic haha and no way could that many little stones be flicking up... all the time!
A recording would be pointless beause the motor makes so much other noise... and it never does it whilst idling, all you can hear on idle is ticks and rattles lol

There's a slow weep of oil onto the driver's side header from the rocker cover gasket but surely that wouldn't be enough to cause heat expansions/contractions at speed though would it....? Surely not.

I really don't want to spend the money on a timing chain as my next car should be a VP Calais anyway and legally you can't use an older motor in a newer car.. otherwise I'd probably rebuild the whole thing.

Yes I'm running 95RON with a greenfoam tune but used to happen on both 91 and 95 on the factory tune as well.

[vnv8driver]

hmm bit of a stumper, maybe take it to a shop so someone can listen to it. Probably get a better idea diagnosing it in person.

[savage1987]

don't care enough... maybe if it starts making more serious noises I will. It only happens when you drive it, not many workshops I know of are happy to come for a drive to listen for noises.