Hello

Having an issue with my S40's engine, seems like the valves are making a tapping sound on start up, it does seem to disappear occasionally but returns even when the engine is warm. I have added some hydrolic lifter additive to the oil but this has only made it worse.

What is the solution to this very annoying problem??

Help!

 

Could it be an exhaust leak? When my 1.9L engine made tapping noises on start up it was a loose nut on the exhaust manifold studs. A stop nut fixed it from reoccurring.

With an overhead cam engine it's highly unusual for valve train noise. On mine the fuel injectors are louder than the cam and valves.

 

Thanks for your reply but it's definitely not the exhaust.

 

Do you have a mechanics stethoscope? Another method is a simple rubber hose held to your ear. Have someone start the car cold and try to pinpoint the tapping noise. The valve train mechanics are very straight forward. Cam - bucket tappet - valve stem. Mine did not have a method for adjustment other than replace the bucket tappet with a thicker one.

Have you a loss of power? Although rare it's possible a valve spring has broken and is rattling around. There is no room for anything to fall down under the tappet from above.