Allo allo

[whatarascal]

Allo people

My name is Brian I live in Wiltshire UK.

I have owned a 1991 940td estate since 1993.
The old girl has no rust "well it wouldnt would it"and has never failed an mot wow.
There have been some advisory notes the last couple of years so I am expecting a failure pretty soon.

I have run it for the last two years on hombrew biodiesel,apart from hoses melting it runs like a dream on the stuff.

It has an intermitent tappety noise,thats the reason I have joined this forum.
Perhaps I can learn something in my old age.

Too ashamed to post pics afraid paintwork has been neglected,still not ashamed to drive it though.

[freds83]

paint dont mean any thing check out the post rite under yours by stroked383 he has moss growing on the side of his car :D

[piper109]

Hello Brian,

I used to date a girl in Salisbury but that was many, many years ago now.

Your intermittent tapping may be the vacuum pump. It reputedly can do this. If it was valve clearance you would hear it all the time.
Are you sure its not piston slap?
Is it louder when the engine is cold?
Does it disappear if you rev the engine?
This link might help.

http://www.brickboard.com/FAQ/700-900/EngineDiesel.htm#TurboDieselVacuumPumpNoise

cheers,

Steve

[Benzsc1]

Hi Brian,

I get the same on my D24 engine but in an LT Volkswagen I reckon it is the vacuum pump although not sure if your Volvos use the same type of pump as on rthe commercial engines.......

[whatarascal]

Sorry for the delay in posting.

The noise started around 50k ago and was intermitent but gradually over the years has become more regular..

Although when the engine is first started the tappety noise is not there untill it starts to warm up.

I intend to investigate when the weather gets a bit warmer I have more time on my hands now.

I did get a stethoscope and listen and I suspect it was noisier around the vacum pump area although there is such a clatter from this engine its hard to be sure.

[whatarascal]

I think I read somwhere that the pushrod to the vacum pump can be removed and the engine run to see if the noise still exists.

Can anyone verify this please

[piper109]

I see no inconvenience to that. The pushrod slides in a bore which aligns it with the camshaft. It is just a straight rod with a flat on it to promote lubrication. Nothing will fall out or befall the engine.

Obviously the brakes would be very heavy!

[ngoma]

I heard you need to replace it in the same direction you removed it. Something about the wear patterns?