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[Salty]

Ok looking for a few opinions here. I have a tapping sound when the engine is cold, sounds like a badly adjusted tappet but as the revs increase it sounds more like a leak from the exhaust quite close to the engine. The thing that is confusing my thoughts on the issue are that it sounds louder inside the car than with my head under the bonnet. I'm sure it sounds worse under load as well, but goes away when the engine has warmed up a little. Further to all of this after the car has stood for ten to twenty minutes after a long run the sound returns on restarting and takes a couple of minutes to go away again.
I've checked under the car and can't see any obvious holes around the front end of the exhaust system, but the down pipes have a sort of double skin to them which is loose so i can't see if there are any holes here.
anybody any ideas? btw its a 3 litre v6

[STMO123]

From what I've read previously it sounds like the dreaded manifold gasket,Salty

[Salty]

I was thinking that way myself, but it may be the easy side to do.

[STMO123]

There's an EASY side?

[Salty]

Well maybe not, looking at it I think the drivers side may be easiest.

[STMO123]

I have this theory about omegas:

Things go wrong, manifold gaskets, knock sensors, power sounders etc, but they dont STOP. they just keep going. So, ignore it

[Martin_1962]

Definately gasket

[Salty]

well that's two votes for manifold gasket. does anybody know how difficult they are to change? Haynes book of lies suggests that the righthand/drivers side bank can be done in car, but that you need to remove engine/cylinder head to drivers side bank?

[Salty]

or any other suggestions as to cause of noise?

[johnny.dee]

do not the omegas have hydraulic tappets, it might be the oil drying overnight and when started sounds tappetty untill warm. could be your oil. this problem is overcome by using fully synthetic oil.
just another alternative thought, as it used to happen in my sports car until it was recomended I change to synthetic, tappy moise then stopped.

[Salty]

do not the omegas have hydraulic tappets, it might be the oil drying overnight and when started sounds tappetty untill warm. could be your oil. this problem is overcome by using fully synthetic oil.
just another alternative thought, as it used to happen in my sports car until it was recomended I change to synthetic, tappy moise then stopped.

It's a thought, currently using the GM semi-synth which was changed the other week. The noise comes back when the car has been stopped for 20 mins or so and restarted so everything is still warm at that stage but not up to running temperatures.

[EddieX]

Yes it could be a tappet draining down. On my last car, the hotter the engine was before parking, the louder the tappet noise the next morning. Which points to thin, hot oil draining from the hydraulic tappets. A change to the thicker 'racing' version of Mobil 1 helped.

Eddie.

[Salty]

If it were a tappet would it not go away as soon as normal oil pressure was achieved? Or does the oil struggle to get to the tappets?

[nigsey1600e]

I am sure i have read somewhere that knackerd EGR valves  can make tapping noise when cold so for a easy check/fix try unpluging  the connector on that whilst running when cold hope this helps  :-/

[Salty]

I am sure i have read somewhere that knackerd EGR valves  can make tapping noise when cold so for a easy check/fix try unpluging  the connector on that whilst running when cold hope this helps  :-/

Thanks, definitely worth a try and cheap