2.5 Diesel Tapping/knocking

Just been recovered after my series 11a developed (extremely quickly) a
loud tapping noise whilst travelling along at ~45 mph.

Sounds exactly like a knackered cam lobe sounds, ie half engine speed,
but it is virtually undetectable at tickover, getting louder as the
engine is revved.

I ran into a local garage, they diagnosed a knackered small end bearing,
but I am not convinced of this due to the half engine speed nature of
the noise.

The engine is a 2.5 litre N/A from a sherpa, and has been faultless
until this occurred. The engine appears to vibrate more as it is revved
than it used to.

I am hoping for a valve gear related problem that won't take too long to
fix. Does this engine have any 'known' problems that may cause this noise?

Thanks all, Terry

"terry" <[email protected]> wrote in message
news:[email protected]...
> Just been recovered after my series 11a developed (extremely quickly) a
> loud tapping noise whilst travelling along at ~45 mph.
>
> Sounds exactly like a knackered cam lobe sounds, ie half engine speed,
> but it is virtually undetectable at tickover, getting louder as the
> engine is revved.
>
> I ran into a local garage, they diagnosed a knackered small end bearing,
> but I am not convinced of this due to the half engine speed nature of
> the noise.
>
> The engine is a 2.5 litre N/A from a sherpa, and has been faultless
> until this occurred. The engine appears to vibrate more as it is revved
> than it used to.
>
> I am hoping for a valve gear related problem that won't take too long to
> fix. Does this engine have any 'known' problems that may cause this noise?
>
> Thanks all, Terry.
Hi Terry,
It is possible it could be a hotspot or pre combustion chamber that has
come loose in the cylinder head on one of your cylinders, quite common.
Regards Rotty

terry wrote:

> Just been recovered after my series 11a developed (extremely quickly) a
> loud tapping noise whilst travelling along at ~45 mph.
>
> Sounds exactly like a knackered cam lobe sounds, ie half engine speed,
> but it is virtually undetectable at tickover, getting louder as the
> engine is revved.
>
> I ran into a local garage, they diagnosed a knackered small end bearing,
> but I am not convinced of this due to the half engine speed nature of
> the noise.
>
> The engine is a 2.5 litre N/A from a sherpa, and has been faultless
> until this occurred. The engine appears to vibrate more as it is revved
> than it used to.
>
> I am hoping for a valve gear related problem that won't take too long to
> fix. Does this engine have any 'known' problems that may cause this noise?
>
Maybe a sticky injector.

--
EMB
change two to number to reply

On Wednesday, in article
<[email protected]>
[email protected] "terry" wrote:

> Rotty wrote:
> > "terry" <[email protected]> wrote in message
> > news:[email protected]...
> >
> >>The engine is a 2.5 litre N/A from a sherpa, and has been faultless
> >>until this occurred. The engine appears to vibrate more as it is revved
> >>than it used to.

[snip]

> Does anyone know if the sump can be removed, and pistons removed without
> removing the engine block?

I did it that way to a 2.25 diesel, many years ago. Jacking to get some
good blocks under the front wheels will help with access. I don't
recall if we changed all the pistons or not.

--
David G. Bell -- SF Fan, Filker, and Punslinger.

"History shows that the Singularity started when Sir Tim Berners-Lee
was bitten by a radioactive spider."

terry wrote:

> Just been recovered after my series 11a developed (extremely quickly) a
> loud tapping noise whilst travelling along at ~45 mph.
>
> Sounds exactly like a knackered cam lobe sounds, ie half engine speed,
> but it is virtually undetectable at tickover, getting louder as the
> engine is revved.
>
> I ran into a local garage, they diagnosed a knackered small end bearing,
> but I am not convinced of this due to the half engine speed nature of
> the noise.
>
> The engine is a 2.5 litre N/A from a sherpa, and has been faultless
> until this occurred. The engine appears to vibrate more as it is revved
> than it used to.
>
> I am hoping for a valve gear related problem that won't take too long to
> fix. Does this engine have any 'known' problems that may cause this noise?
>
Maybe a sticky injector.

--
EMB
change two to number to reply

On Wednesday, in article
<[email protected]>
[email protected] "terry" wrote:

> Rotty wrote:
> > "terry" <[email protected]> wrote in message
> > news:[email protected]...
> >
> >>The engine is a 2.5 litre N/A from a sherpa, and has been faultless
> >>until this occurred. The engine appears to vibrate more as it is revved
> >>than it used to.

[snip]

> Does anyone know if the sump can be removed, and pistons removed without
> removing the engine block?

I did it that way to a 2.25 diesel, many years ago. Jacking to get some
good blocks under the front wheels will help with access. I don't
recall if we changed all the pistons or not.

--
David G. Bell -- SF Fan, Filker, and Punslinger.

"History shows that the Singularity started when Sir Tim Berners-Lee
was bitten by a radioactive spider."