Hi,

My 2.5 is doing an increasingly good impression of a London taxi at idle. It performs ok, seems a bit sluggish low down relative to its predecessor and does alot of high speed motorway driving. I would appreciate any advice on whether it's usually a case of freeing off clogged hydraulic tappets, or finding that they are worn and need to be replaced with known good ones.

I'm thinking about two options. Take the existing tappets out, put them in paraffin or something for a week, make sure they function by hand, oil them and put them back. Or fit the tappets, camshaft and valve gear from the spare engine in my old 2.5 that was much quieter until it's head gasket went.

Has anyone had any luck in quietening things down at idle?

Cheers

Marc

Hi Marc

On a 2.5 with a/c if the idler pulley and aux belt are on the way out it can make a tremendous amount of noise at idle. Quietens on load. Very difficult to spot visually and you can need to put a stethescope on the head to convince youself it is not noise from the top end.

John

Thanks John,

I'm familiar from previous experience of the horrible noise on start up from a slipping aux belt and broken spring, but this car doesn't do that - yet! Just sounds like noisy tappets that are way out on an old petrol engine and the noise goes away once I'm over 50mph or about 2000rpm.

I cleaned and freed up some hydraulic tappets from a spare head, they now move in and out by hand easily but some were really tight initially. Not sure if these things seize up but have got a spare set now.

Anyway will check pulleys and replace belt first as it's well worn.

Cheers

Marc