Hi yes they do tick - but its a gentle tick
if you have a loud tapping its most likley a tappet or the exhaust manifold gasket
cheers
Steve

 

Could also be the idle control valve, When mine was gunked up it was making a ticking noise.

Rob

 

The injectors on my Volvo (five of em) tick, but it's not outrageously loud!

 

Some great replies here! Thanks.

It's hard to judge how loud the tick is - It wasn't loud enough to cause me too much concern when I thought it was tappet just annoying, I've heard worse! But it's just audible with the bonnet closed standing at the front of the car.

I am confident it's not the idle control valve due to proximity and that I've heard that before under ECU diagnosis conditions - it's a duller sound IMO. I recently cleaned it as well.

Can I test the injectors by disconnecting their plugs one at a time with engine running?

Can I test the exhaust gasket theory and how?

And, assuming it's an injector, is it causing or likely to cause any problems? Would I need to replace one or all and how expensive are they?

 

Oh, I forgot to mention that I replaced my injectors about 20k ago and noticed no difference in either performance or noise!

 

If the bonnet is closed it is likely to be tappets,or as mentioned an exhaust gasket blowing.The injectors do click,but very quietly,and you will only hear them on tickover with the bonnet open.Jerry

 

You can see if the exhaust gasket is blowing by looking around the manifold for sooty deposits, mine leaked at the top left hand side where a bolt had sheared off.

Rob

 

if your oil level gets too low this will also make it tap loudly.

 

if your oil level gets too low this will also make it tap loudly.

Not for long,though:lmao: Jerry

 

Ok, just to clarify some points. I cannot hear any ticking (bonnet open or closed) at any revs other than idle - perhaps that demonstrates how quiet/loud it is?

Earlier, I failed to realise the exhaust manifold is on the front of the engine and I'm 90% sure the noise is definitely emitting from behind it. I will try and pinpoint it later but there is no soot or other indication the gasket is leaking.

Old oil, new oil, always within the dipstick limits, I hear the same noise. I'm even running slightly thicker diesel oil this time in an effort to clean years of built-up sludge and the noise remains the same.

Given the above, it does still point towards an injector. Is it ok to disconnect them individually with the engine running?