rjben

Can somebody put my mind at rest? Recently my car has started to make that heat shield / metal pinging noise more and more. It used to just occur when the car was warming up / cooling down, but now I can hear it when idling and accelerating. Even giving a blip of the throttle when in neutral causes the the noise. Am I just panicing here? I thought the det or 'pinking' will only occur under load?

The noise seems to have got worse since my Magnex BB and CC were fitted - could it be a bad joint or my turbo heat shield?

Help,

Rob

nom

It's not detting if it does it in when not under load - so that's one worry out of the way!
Always tricky to know what's wrong with noises...

rjben

Cheers, I'll get somebody to look at it when it goes for a service, just need to know if it's getting damaged in the meantime.

Rob

scoobyslut

be careful, if you get the noise when engine is running, just as you go to overtake and put the engine under load, it may then be "piston slap", not "pinking", best to get it checked properly before you do any damage and costs you loads.

rjben

Nope, it happens even when the car is in neutral. It's not slap as it's not at all relative to engine speed. It doesn't sound like slap anyway (I think!)

I've heard of some cars with slap when cold, but goes after 10mins or so when car is warm. What happens if you ignore this and just take your time until the noise goes? Will it do any damage?

Rob

nom

Piston slap is no real problem - it has even been stated that this 'looseness' is no bad thing & may actually be preferable!

rjben

thanks for that, I can hopefully get some sleep now!

rjben

Anybody else got some ideas about this?

Cheers,

Rob

scoobyslut

"If" it is piston slap, yes you can continue to run the engine, but the piston itself is actually "running "undersize" in the bore, which will ,in time cause it to keep trying to turn slightly in the bore, causing wear to the block bore and, obviously, to the piston itself. It may also cause the hot combustion gases to tend to run down the side of the piston, instead of staying on the top, this then induces the side of the piston to "burn up" and be burnt as the engine runs
So, would still suggest you just at least get a "decent" garage or engine company to have a listen, purely for "peace of mind". I would not sleep easy if it was mine doing it untill i had had better re assurance then email suggestions over the internet.

rjben

Thanks,

I'll get it checked out at the next service (800 miles)

Cheers,

Rob

rjben

Thought you people may be interested.....

Went to kwickfit who kindly removed the heat shielding between centre section and front cat. The noise has now gone! Brilliant.

I'm assuming it's ok to remove this as 3rd party exhausts don't have shield?

Cheers,

Rob

nom

3rd party downpipes don't have the shield because they don't have the cat! A DP with a cat gets rather hotter than one without. Not too sure of the solution here (other than to just go with a decat DP ) as heat-wrap is likely to break the cat (retains too much heat). But good to hear it was something simple!

rjben

so whats the worst that is going to happen - my cat gets broke?

OR is my Scoob going to go up in smoke !!!!!

Cheers,

Rob

nom

It might crack the DP somewhere, which isn't a disaster but things might get noisy Or the cat might just break down... but the thing I'd worry about is the damage the extra heat without the casing might do. Lots of things around that part of the engine which are all trying to ditch heat and this isn't going to help...

rjben

Cheers NOM,

I guess I'll wait for burning smell, MOT failure or flames them ;->

Cheers,

Rob