Quote:
Originally Posted by X5only
I changed mine and it started leaking again from the case after a year or two. I did it again but applied a thin layer of sealant and that fixed it. Thin layer only, like barely!
|
There's a big omission from the BMW TIS system regarding sealing the valve covers. My Snap-On man is a former BMW Master Mechanic whom I consulted before doing the valve stem seals job on my buddy Dave's X5. When getting ready to replace the valve covers I noticed a relatively big bump of timing case gasket extruded up at the front top and bottom of the head. I measured it with a feeler gauge; the ridge of rubber sat off the head's sealing surface by 66 thousandths (about 1/16"). I asked Mr. Snap-On about this - he told me I must trim the protruding gasket flush with the sealing surface, suggesting a lubricated single-edge razor blade so the gasket wouldn't tear.
No way the valve cover gasket would have sealed with a wisp of RTV silicone and that big ridge. See attached photo.
The valve cover I removed was leaking, even though the dealer had changed the valve cover gasket only last November, 2017.