Has anyone seen any information about silicone products causing O2 sensor damage ? I have used silicone grease on vacuum hoses on my 560 SEL. Thanks for any input..

H. O. Tyler
560 SEL 1990
300 SD 1985
240 D 1985

Silicone
 

I remember reading a report claiming that silicone lubes
are poison to and will damage an oxygen sensor. I think it was related to the Jeep Grand Cherokee that I had

Why you asking this question? Did your O2 sensor go out and why you putting WD-40 in vacuum hoses? I am just trying to understand the purpose of your question.

Hello Benzmac:

Do you have any comments about silicone lubs and O2 sensors. Is it a problem if you use them on the intake vacuum system. I replaced nozzle holders and a couple of brittle hoses and used silicone grease to help them seat together. Please let me know your comments.



Thanks, H. O. Tyler
1990 560 SEL 120K
1985 300 CD 62K
1983 240 D 260K

Silicone grease is fine on hoses, connectors, as long as you don't slobber it all over the place. It has high thermal resistence and will not degrade the rubber (neoprene). Silicone sprays should not get inside the engine, but why would anyone use it in that fashion anyway. Silicone is a fairly inert substance and if you use it properly, you will be fine. I use it for all kinds of lube issues. Really great with suspension bushings which are squeaky.

Hello Jeffsr:

Silicone grease is a excellent grease/oil lubricant for vacuum systems, electrical and other applications as well as a preservity for neoprene and rubber components. I used it on the replacement of old brittle leaking components on my fuel injection nozzle guides, holders and vacuum lines. So I am asking if anyone has any data that would confirm that the use of silicone lubs on the intake fuel injection for a 560 SEL is a problem for the oxygen sensor ?
The application was a very thin layer for the lubricating, sealing of hoses and "O" rings. I heard the comment about silicone and O2 sensor on the Crank & Chrome show on TNN. So I thought I would see if anyone has any info.

Thanks, For any Comments.

H. O. Tyler

You are fine. Just use it sparingly. A little goes a long way. If anything, the fuel pressure would be pushing in the opposite direction..