pale orange catalyst and lambda sensor

pale orange catalyst and lambda sensor

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spitfire4v8

Original Poster:

3,990 posts

180 months

Wednesday 11th January 2017
quotequote all
Have a car in the workshop at the moment .. exhaust is off and one of the three catalysts is loose in its housing .. the catalysts also have a very pale orange hue to them and so do the lambda sensors ..
traditionally this might be down to lead poisoning, but as leaded fuel is very rare these days, and the car is a catalyst car so the owner wouldn't purposely use leaded fuel, this might not be lead poisoning ..

The only thing the owner does use is a treatment to keep the fuel from going off quite so quickly .. the car is laid up for some months at a time and the owner adds a treatment (made by millers I think) and I'm wondering if this is the cause of the orange hue and possibly the premature machanical failure of one of the catalysts.

has anyone come across other reasons for a pale orange hue on catalysts or lambda sensors, or has anyone heard of fuel treatments causing issues like this?

any help appreciated

stevieturbo

17,229 posts

246 months

Thursday 12th January 2017
quotequote all
And why does he think the fuel will go off ? Is he leaving it for several years at a time ?

And yes, many additives can cause colouration like you describe.

But the problems....maybe not.

Edited by stevieturbo on Thursday 12th January 10:06

spitfire4v8

Original Poster:

3,990 posts

180 months

Thursday 12th January 2017
quotequote all
I wondered if it was the additive doing the colouration .. spent a while googling but didnt turn anything up other than lead poisoning again so good to hear that they can cause coluration.

Also to be fair finding a loose catalyst in a tvr manifold is not uncommon so may not be anything to do with the additive, but if the lambda probes are poisoned and not working (the engine has been plagued with running faults in the past) then this is the probable loose catalyst cause - overheating of the substrate because of misfires. Engine not running at the moment so difficult to test .. might quickly put the lambdas into another car and test there.

cheers

zombeh

693 posts

186 months

Monday 16th January 2017
quotequote all
Yes.
Plenty of things they might be putting in the fuel will leave orange deposits on stuff. MMT for example. Whether you'd get enough to kill a lambda sensor or a cat I've no idea, probably doesn't help though.