Where is this Tapping coming from???

[toboris_w]

Here is the deal. My 1990 190E is making a tapping sound from the top of the engine every now and then. The oil is changed on a regular base with the good stuff (Castrol).

Tapping Traits:
The tapping starts and stops on its own, some time over a month apart. The sound is not consistent, loud some times soft other times. The tapping usually last from 10 to 30 minutes when it happens. At speeds over 30 mph the tapping stops, but when I come to a stop it start again.

I know the engine has over 287,000 miles, but I wold like to keep it another 200,000.

Does any one have any ideal what it could be?

[MrCjames]

Hi

You could have one of two things happening.

First: Lifter bleeding down

Second: Camshaft wear/rocker wear

You'll want to start with a complete visual inspection of the valve train. Remove the oiling tube to get a good look at the camshaft.

You may need to remove the cam tower assemblies to completely inspect the rocker surface.

CAUTION: Shims located on top of the valves, work with care so these do not get lost (they do fit in the oil drain holes located on the exhaust side of the cylinder head)

Let us know what you find!

[toboris_w]

Thanks for the reply.

I called a friend that had the some thing happen to his 325i 2 years ago. He used engine flush followed by adding 1 quart of Rislone Engine cleaner from AutoZone. He told me it has not made a tapping sound yet. I did the flush and Rislone yesterday so will have to wait to see if is did the trick.

If it happens again I will be using your advice MrCjames.

Thanks.

Does the tapping occur after a hard break when the car is in motion?

Cheers,

jlam

[toboris_w]

When the tapping occurs its starts after all stops, hard or soft.


2Boris

Why not check your front brakes. It might be an uneven wear on the face of your disc. If you can, try rotataing the brake pads per disc and see if the tapping stops.

Just a thought.



Cheers,


jlam