Jamz3k

My car is making a tapping noise when accelerating. I can't hear it unless I have my window open but under load its definitely noticable but disappears when at a constant speed. I've also noticed that the sound is constant whether the engine is hot or cold but seems to be a bit louder when the engine is hot. Its worth noting as well that is is RPM related rather than speed related.

It sounds like its coming from the front of the engine, initially i thought it was to do with the manifold heat shield as it was cracked from underneath. Once removed and test driven, the sound still remained. Then thinking i may have a crack in my manifold, I did the paper test and couldn't find any leaks.

With the heatshield off the sound became a bit easier to track to the front right of the engine.

I'm baffled any help would be greatful.

here is a video as I tried to record the sound but unfortunately my phone couldn't pick it up well, if you listen carefully the tapping can be heard
http://www.youtube.com/watch?v=IYo3aImutbo.

The Zohan

split/lowing exhaust manifold/gasket by the sound of it (no pun intended).

check the exhaust manifold studs are tight and see if there is any soot on the head around the manifold.

Jamz3k

could you hear the tapping noise Paul or are you assuming thats what it may be?

The Zohan

What you describe sounds like a blow next to the head between the head and manifold or a split in the manifold - i would put money on it. as i said check the head bolts and look for soot/deposits.
Cannot hear a thing on the youtube clip!

MMT WRX

I can hear it. But sorry not a clue what it could be though. The clicking is there though if you listen carefully.

Jamz3k

Thanks Paul, will have to wait till next weekend to have a good check!

Jamz3k

well least i'm not going nuts!

MMT WRX

Could it be an injector?

My Mrs car has one that ticks a bit when its really cold.

Jamz3k

I honestly don't know enough about mechanics to make a judgement. It looks like i'll be going up to my mechanic next week to spend more money i don't have.

I so wanted to get started on a home cinema room this year too!

Ayde

iTrader: (6)

If it's an Alfa twin spark it sounds like it's your variator, google it, think it's quite a common issue

Jamz3k

Its not the variator but good guess!