I am getting ready to replace O2s again after Power Steering fluid sprayed everywhere. Anytime I start a project even one I have done before I always do a search for any new info.

This time I found a post that said not to apply Dielectric to the O2 Sensor plug contacts because the dielectric can block the readings, Is this true?

I always take the time to thoroughly clean the contacts with electronic cleaner & Q-tips.



Thanks

 

I've never used it on them, it does not say to in the instructions, so I never do.

 

I always use dielectric grease on connections. True, it(the dielectric grease) is non conductive but the reason to use it is to prevent conductive liquids (water, oil) from causing a bridge between contacts or between a contact and ground. When the metal blades of the connector make contact the circuit is completed and the dielectric doesn't affect that circuit (except to prevent unwanted pathways).

 

This can be used on pretty much every connection in your truck and in the case of the front 02's it is great cause they usually get covered in engine oil from leaking v/c gaskets.
The only thing I suggest people use it on it the plug wire connection to the coils cause sometime they will pop out because of the angle and not always getting a good connection.

 

Thanks I guess it should be OK then to coat the metal contacts also.

I am really thinking of trying another idea from another poster about using Liquid tape on the outside of the connector.

 

Just so you know, the O2 connectors are water tight.

 

It cant hurt anything, it will keep moisture out and i recommended that just for that reason. Also if you make sure the connectors are in there proper place not just hanging down. Good luck!

 

Not likely in many cases since corrosion needs moisture & oxygen. Maybe they were for a very short time. I have seen many with same issues I seem to get.

All I know is mine work fine until something happens like washing engine or a major spraying leak.

I have managed to keep engine leaks to a minimum so no continuous valve cover leaks. I even had to change throttle body heater because it developed a very small leak. I have decided with rovers I can;t stop all leaks but I will keep trying as futile as it is because I hate leaks LOL.

Again only time I have had issues with O2s is when engine has been washed or major leak. Dealer never cleaned or used dielectric which once caused an early 2 week failure. I always clean but wasn't sure about dielectric on actual contacts.

So since plugs contacts seem fine I think I need to try a little extra waterproofing if it wont hurt to that is?


Im by far not a mechanic so I try to do what others have already proved works & have found good advice here in past.

Thanks everyone that takes time to help it is very appreciated.

 

If the DII are zirconia sensors then no, do not use anything on them.
I was wondering about this myself and talked to an engineer at NTK, this is what he told me:
Titanium sensor - ok to use dielectric grease on the electrical connector
Zirconia sensor - uses reference oxygen pulled in through connector, so not ok to use dielectric grease

I don't know for sure, but I'm guessing the DII is Zirconia as that's the newer technology.

 

Your past post was the reason I questioned using it since it didn't actually say DIIs were zirconia in the one I read.