Nasty noise, place your bets.

[vcosmin]

For about 3 weeks my AAN S4 started to make some noises getting progresivly louder. My friend which is a mechanic said it piston pin, or worst :-) , i hope it's just a stucked tappet. - so from noise what to expect (engine will be opened tommorow). Oil pressure 2 bars on hot idle, engine compresion 140-150 across all cylinder with one beeing 190 ?

http://www.youtube.com/watch?v=n_WQDO7-Lps&feature=youtu.be

[Avantus]

Con rod bearing I'm afraid.

[Thuppu]

Con rod bearing I'm afraid.

+1

Don't use the engine at all anymore! If you are lucky there is no damage on the crank and you can put new bearing shells. This job is quite easy to do underneath, no need to take the engine out.

[AndyP]

I had a sticking tappet on mine and it didn't sound like that

[macspring]

Too much additional noise over and above the sticking tappet like part of the noise.

Be sure and post the fault when you know for sure.

Best wishes for it to be reasonable.

Was the oil a bit low or not changed for ages ?

[vcosmin]

not realy, new bearings about 6month ago. the conrod bearing should not sound diferent on cold and warm oil ?

[Avantus]

Will pretty much be the same noise warm and cold

[nip]

Loose spark plug maybe

[Monkeymagic]

While it is running pull each coil pack/ht lead in turn. If its con rod bearing the noise should stop as you take away the spark to the affected cylinder.

[simon20vq]

Funny sounds like top end of engine to me? Are all the plugs the right colour i.e sparking?

[vcosmin]

So far spark plugs ok, tappets ok, next engine out .

[vcosmin]

Back, conroad bearing - i'll take some pictures.

[macspring]

Tough break, silver lining is that it will be fresh when rebuilt and the cost of the rebuild recedes into history.

[vcosmin]

Probably the bearing spined a lot getting so smaller in size.

[simon20vq]

Thanks for up dating us. Always good to know what the fault was. All the best with the rebuild.