Using Silicone RTV Gasket Adhesives

Alert! Use at your own risk

For those of you who are not already aware of this potential for trouble, my recommendation is that you do not under any circumstances use any type of silicone gasket adhesive on any part of your engine whether diesel or gasoline. I cannot express my dismay at how many times I have seen silicone particles running loose inside an engine. It can often lead to major engine damage. In the pictures here someone had used a silicone gasket sealer on this 380SL engine. When I removed the cylinder head I found this big clump of blue silicone actually plugging one of the passages in the engine block. I've seen silicone gum up climate control units, plug cooling systems and even plug up oil passages inside engines which all can lead to catastrophic failure.

Silicone gasket adhesive

Problem & Solution

Common among these chassis:

W108 W109
W110 W111 W112 Sedan
W111 W112 Coupe
Classic Sedans

Obviously if the silicone is applied properly in a very thin layer, damage and problems could be avoided. But in most cases I find that previous owners/mechanics have applied this stuff very thick allowing it to bead up inside whatever they are sealing. This "excess" eventually falls off inside the engine. I prefer to use Aviation Permatex gasket sealant. I've used it for years with good results and have seen no problems with this material coming loose and plugging internal engine fluid passage. So a word to the wise "mechanic beware" do not use silicone.