I am thinking that the reason for my O2 constant failure and cats not working at their best could be from the oil consumption of RotellaT and T6 over time. It my not be the problem but it's just a theory. I use quite a bit of oil expesally at startup.
If the chemicals that are in T and now T6 are backing on the O2 and cats, is there something that will remove it?
I tried a soak in soapy water overnight but moved from the emission testing area before I could tell if there was any affect. I did notice the smell was different. It was the same smell when I put a new cat on an older vehicle. I know that's not scientific. I do know that in Europe there was reasearch on citric acid and how it could clean diesel cats. I have a gas cat but use diesel motor oil. Not sure how much of the cause of diesel cat contamination is from diesel fuel and how much, if any is from diesel motor oils.
Removing burnt on RotellaT syn oil from cat/O2
- Thread starter landtoy80
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What is said vehicle?
IF you want to waste your time you can try cleaning them, but the best bet is to reduce your consumption issue and replace the damaged parts.
94 Land Cruiser
411,000 mi
1 qt first 2000 to 3000 mi. It gets down to about 1qt per 1000 mi +- at about 9000 mi +- oil change. It starts out with fresh oil and 1 qt MOS oil additive from Liqui Moly. I assume that as the consumption of oil is used and when I add more oil the ratio of MOS is decreased and that increases consumption. But even without the use of MOS, the consumption is increased as the oil gets older.
Yes, the cats must be past their normal life, but the same could be said about the motor in the Land Cruiser but it still runs on.
I gave up replacing the O2's and it now runs default mode with no O2's checking the fuel ratio. The EGR is not working either, not much to fix that though. With all the miles and no O2's, the LC has more power than it has had in the past. May have to due with the O2's always getting fowled??? Not sure.
I did play with unplugging the O2's and many miles later plug them back in and they worked fine (no codes) for several months before finally dieing. Was told that some have had luck with removing them and heating with propane torch to clean them, I have not tried that.
Back to cleaning the Cats and O2's. When I had the cats and O2's off, there was a light brown/grey glaze on them. I would assume its the oil??? With the O2's unplugged, I get black soot inside the tail pipe. Maybe running a little rich?
When I tried to pass emissions 3 years ago, I got very close with new O2's and a working EGR. A new set of cats would of done the job.
I was just thinking of removing the cats, I have SS bolts on the cats and its an easy job removing them now, and cleaning them somehow, just to see if I can pass or even get close to passing than I did 3 years ago. If it works, then I have saved a few buck, if not, then all I have to do is buy new cats.
It looks like its ZDDP or zinc that may be what is coating the cat and O2's.
What chemical will remove ZDDP/zinc?
It is the Phosforous from ZDP that cause coating problems. Maybe a good torch on it ...
Even if you never used HDEO, that rate of oil burn would still quickly destroy smog devices.
The only solution is to repair your engine.
Some people do use Citric Acid on gasoline cats and get positive results. I think Scotty Kilmer showed how to perform the procedure.
Originally Posted By: fdcg27
I'll put on my fireproof underwear and note that Shell specifically recommends that Rotella oils not be used in any vehicle with a catalytic converter.
Originally Posted By: fdcg27
I'll put on my fireproof underwear and note that Shell specifically recommends that Rotella oils not be used in any vehicle with a catalytic converter.
If an LC with 411,000 miles is consuming some oil and has failed cats, I wouldn't be surprised. I also wouldn't be blaming the oil.Don6t use anything ever on the lambdas.
NO:
oil
contactcleaner
soap
anti sieze
There is a membrane that lets it have outside air as reference
and if you get anything in there its destroyed...
Most sensors get their Death sentence when they are new and getting installed, some anti sieze here and some Contact cleaner here and it fails way to soon...
The cat are doomed the second you decide to run without the lamda...
As for blaming rotella...well you also poured mos in there so..
I am not blaming anyone as I stated at the start of my post. I was just questioning weather or not the oil is a problem with smog parts or not.
I got this from Shell:
Dear Sir,
If you are using oil between oil changes (consumption), then you can shorten the life of a catalytic converter which is the result of the ZDDP additive contaminating the catalyst. It is for this reason that we do not recommend using Rotella oils in gasoline engines with catalytic converters. There is no way I am aware of to remove the conatmination once it is attached to the catalyst.
Regards,
Shell Technical
IF there was a problem with oil contamination, then the issue could be resolved with proper chemicals (that is IF its the cause of the problem). Thus the reason I asked on this forum.
IF gas cats can be cleaned like the diesel cats can be in Europe, then a proper chemical can be used to clean them.
When I have removed the cats in the past, they were not plugged. It just had a coating on the filament. It didn't look like the pic's that I saw of cats that had the filament plugged up.
So it looks like my theory of ZDDP on the cats is correct but there is no way to remove, at least from Shells point of view.
Are these the original cats?
Yes. Original cats.
Three years ago I tried to pass the test but failed. Colorado lowered the limits for the 1994 vehicles to CO 20.0, HC 2.0, NOx 4.0. Had the limits not been lowered I would of passed. I failed the NOx. I was told that the old standards were 6.0 NOx. New cats for other Land Cruiser owners got them to pass the test.
I started this post to find out if ZDDP can damage cats and if the ZDDP can be removed. It looks like ZDDP is a contributing cause to cat desegregation and now want to know if it can be removed.
If the ZDDP can be removed without damaging the cat's, then I would like to know how to do it. IF the cats can be cleaned and they work again, is there a problem with trying it?
Well, removing phosphorous from cats is a little out of my depth. I do know that after 411000 miles, those cats owe you nothing. But, like you say, if you can somehow clean them and get them working correctly, there's absolutely nothing wrong with trying, assuming it doesn't cost a bunch of money.
But, like you say, if you can somehow clean them and get them working correctly, there's absolutely nothing wrong with trying, assuming it doesn't cost a bunch of money.Originally Posted By: Pontual
It is the Phosforous from ZDP that cause coating problems. Maybe a good torch on it ...
SH was the API certification when your vehicle was new. The API SH, SJ, and SL oils available for the first 10 years of your Land Cruiser's live had Zn, and P levels virtually equal to CJ4 T6.
In 2004 the EPA required manufacturers to extend the warranty on catalysts to 150K miles. They used their voice in the API to get the Zn and P levels lowered in the upcoming SM certification to reduce their exposure to warranty costs.
At 411K, you are likely more than twice the design life of the catalysts. Running an oil that has Zn and P at the levels in oil when the car was built is not your issue. It's worn out. Rebuild the engine and replace the cats.
Ed
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