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Wideband sensor safe sealant
ChrisL - 21/5/19 at 07:52 AM

Hi,

In the process of putting the car back together and have fitted a wideband 02 sensor. Does anyone know what exhaust sealer is suitable and won't damage the sensor. I was looking at using PlumbaFlue bout not sure if it is safe, alternatively I could use Holts FireGum but don't know if that's safe either!

TIA
Chris

[Edited on 21/5/19 by ChrisL]

40inches - 21/5/19 at 08:10 AM

I used the cheapest silicon sealer I could find, and never had a problem. I think that when the sealer has cured (24hrs?)
all the harmful gases have gone.

Theshed - 21/5/19 at 08:57 AM

All the sensors I have ever seen seal using a crushable washer at the top of the thread. They do not need to seal on the threads and would be a bit of a pig to remove if they did. They come coated in anti-seize compound so I would just use that.

I do not pretend to know but I understood that wideband sensors hated silicone. In any event surely a silicone sealer would burn off in seconds?

ChrisL - 21/5/19 at 09:36 AM

The sealant would be for the exhaust joins and not the sensor itself
On the once it is cured it'll be OK, not sure if that's true as I'd imagine it'll give off more fumes the first time it is heated. And that probably holds true for whatever sealant is used...

[Edited on 22/5/19 by ChrisL]

Theshed - 21/5/19 at 09:56 AM

Oops sorry I misunderstood the problem. Why not use a sealer recommended by an OE manufacturer that uses wideband sensors? Or...use any old crap and leave the sensor out for a few heat cycles.

40inches - 21/5/19 at 03:33 PM

quote:
Originally posted by Theshed
I do not pretend to know but I understood that wideband sensors hated silicone. In any event surely a silicone sealer would burn off in seconds?

What can I say? Four years on and no leaking joints and the sensor is still doing it's job.
Andy Bates also uses the cheapest silicon sealer he can find

ChrisL - 21/5/19 at 03:38 PM

Cheers for the advice chaps will let you know how I get on...

MikeRJ - 22/5/19 at 10:19 AM

As mentioned you don't need any sealant on a W/B sensor, they use a crush washer for sealing just like a spark plug. The silvery coloured grease you get on the threads of new sensors is an anti-seize compound. I've used copper grease when refitting them with no issues.