Too much boost. Tapping top end.

[lurchio2]

Hi. I recently changed my mbc and stupidly forgot to check it was wound to minus. Put my foot down. Far too much boost. Now it sounds like it a noisy tappet would sound. It drives fine just has a tapping sound. I used engine flush and changed oil. Only halfords 10-40 semi because money was tight. The sound has quietened down a little but still there. Definatley a top end tap. Sounds like from the back cam. Any ideas??? Thanks. Matt.

[RT MECHANICS]

Hi. I recently changed my mbc and stupidly forgot to check it was wound to minus. Put my foot down. Far too much boost. Now it sounds like it a noisy tappet would sound. It drives fine just has a tapping sound. I used engine flush and changed oil. Only halfords 10-40 semi because money was tight. The sound has quietened down a little but still there. Definatley a top end tap. Sounds like from the back cam. Any ideas??? Thanks. Matt.

Sorry to say it sounds like a bent conrod what boost did it get to ??

[lurchio2]

Hi 20,s it doesn't sound loud like a rod. Not a horrendous noise. Just like a tappet needs adjusting on a older car. But it started when I over boosted.

[RT MECHANICS]

Hi 20,s it doesn't sound loud like a rod. Not a horrendous noise. Just like a tappet needs adjusting on a older car. But it started when I over boosted.

Still think the same a small boost spike will bend the rods...

[shaun850]

As russ said, it's gunna be a bent rod.

Been there done that in my first ever volvo many years ago.

[Volvostorm]

New or rebuilt engine time, me thinks

[stu_850t5]

surely if it was a bent rod, the engine would not quieten down after an oil change.

id carry on driving it till it stops!

[smithy]

surely if it was a bent rod, the engine would not quieten down after an oil change.

id carry on driving it till it stops!

ive seen and heard the car and it is a tappet noise not a bent rod because when you give the car some it goes away and is quiet and then the noise comes back when left to idle for abit if is was a bent rod the noise would still be there or get worse and the car would not pull like it does.but im going to check the car over properly next weekend to confirm things.

[Volvostorm]

It could well be a failed/failing hydraulic tapped, maybe the extra boost pushed the oil out of it?

[mhill53]

That's exactly how mine sounded,was 100% convinced it was little ends the sound disappeared while under load, changed oil and filter which made it less noticeable, stripped it down to find the big end shell had spun in the rod, no matter how much boost your running I'd fit a decent set of rods as they really are the week link in these engines