Lambda's and Silicone

[daveb500]

It looks like I might have dead lambda sensors. I'm going to test them at the weekend and I've then got a RR session with Mark Adams booked for next week.

I know that they don't like silicone but just wondered how sensitive they are to it? It's probably not this but I have used silicone to seal my carbon plenum (per ACT instructions) and I also put a smear on the valley gasket (per LR manual). Could either of these be an issue?

More likely it could be related to the previous issue which was a porous block which mean water going through the exhaust and I gather antifreeze also contains silicone.

I don't want to replace them only to find they die again....they're not cheap.

[Chuggaboom]

I was told I might have the same problem with the racer, as they all had their exhausts silicone sealed to the blocks.

As mine has a Cerb road engine and ecu, it needs the sensors unlike the race cars.

Eventually I found a gasket that fitted with a minor mod.....yeah at 70 odd quid a go they're a bit of a bummer if/then they go duff, especially in pairs !

[Simon says]

Use this stuff its Lambda probe friendly in future http://www.wurth.co.uk/catalogue/pdfs/UK-CD_05_029... i use the black one its also nicer to work with than regular RTV basically if you got to use regular silicone avoid the one with the acid/vinegar odour that's the one that damages sensors

[daveb500]

Thanks, I'll have a sniff

[daveb500]

I've done a bit more research and apparently, you need to use sealants that "Oxime cure".

Mine does so it isn't the sealant. Probably the previous water issue then.

[Simon says]

daveb500 said:

I've done a bit more research and apparently, you need to use sealants that "Oxime cure".

Mine does so it isn't the sealant. Probably the previous water issue then.

They hate coolant/antifreeze so could be