p0420 & p0430 on volvo xc90 2012 Topic is solved

[chitownV]

Just a consideration, if an engine running and maintenance issue is causing the oil accumulation in the catalytic converters and contributing to the P0420/P0430 codes, the engine issues should be fixed first. Since brand new catalytic converters were already installed, if the paint thinner helps clean the cats, this problem will return without fixing the engine issues.

We always start with the known (high-mileage) maintenance first so that new catalytic converters don’t get contaminated. Doing the paint thinner also won’t solve an oil consumption issue, or white accumulation on the spark plugs, or oil burning smell in the engine bay.

Exactly!

But the problem is that i don't have a Clue what is the problem.
Maybe it is the rings... And then i don't have anything to do besides exchanging the engine

.
Exactly! , the problem is that you don't have a Clue what is the problem. You've got to establish a baseline and then test! Going all over the place looking for things unknown without a potential remedy or just replacing parts can get expensive, so is not the way to start.

Changing parts and hoping the code goes away is not diagnostics. Start with the known and it if improves or is gone you're good but if it comes back then you go into the unknowns. Regardless, unless you establish a baseline of no codes you won't know whether anything you do had an effect. Have to clean and clear before doing other things assuming there is root cause or a combination of causes affecting the CAT.

Known:

* CAT was changed and code came back slower.
* Plugs are starting to foul again.
* Problem improved with 0W40.
.
First:

* Clean CAT and if code goes away you know it can go away.
* Change oil to 15W40 and see how long before code returns or doesn't return. If the length between code is extended you know it's an oil issue as the or one of the issues.
* At this point you can start to poke around for the unknown and see if you can find something else potentially contributing to the problem.
* Regardless, you have to bring the CAT back to the baseline or else it's wait and see after you decide you want to pursue the unknown(s) and replace parts as a way of diagnosis.
.

The baseline is doing the maintenance with good parts. Then verifying they are still good. Using a non-OE PCV has seen more issues than not; OE is Volvo, Land Rover, FoMoCo. I can't remember the last time I heard about issues with someone who changed to a new OE-branded PCV. Unless there was some other cause like rusted and leaking downpipes. This is basic 3.2. The PCV could also make the engine stall out, just like in the P3 2.5t engines that have a diaphragm PCV. The difference between the P3 2.5t/3.0 T6 is that the 3.2 does not have PCV hoses.

There are clear external signs of PCV issues, with the new Vaico branded PCV. This would be a priority, along with the catalytic converters if the correct ones were changed and if the cat/manifolds were changed, if they were done correctly.

I would NOT recommend 15W-40 for the 3.2. Let me repeat, don't use 15W-40 in the 3.2. This isn't an old white block or a turbo engine. That will NOT solve carbon build up blocking piston drain back holes. This does NOT address the P0420/P0430 issue.

There are 5W-40 oils that can keep their 40 hot viscosity from getting too thin yet will start up with better flow than a 15W when cold, when oil is the thickest. 15W-40 is truly old thinking. There is a difference between excess oil on the cylinder walls not being able to drain out when scraped off with the piston rings, compared to trying to seal the piston rings. Part of the piston rings are the oil control rings. This is what's being referenced about the piston rings and getting them (and the piston drain back holes) clogged with carbon. It's not just a Volvo issue as most other makes have engines with similar issues. This is one reason not to use a 15W oil in the 3.2 engine.

Have you seen the differences in the clearance of the oil control rings and oil drain holes in the video you linked from my Oil Burning & P0420/P0430 thread?

[EgoziAlon]

I checked with mechanic and he did not replace the gaskets

[chitownV]

So,

Issues with work already done,
- PCV
- Old gaskets used for the (primary?) catalytic converters. Or exhaust paste used for the secondary catalytics?

How were the cats installed?
You also have to verify the mechanic installed ALL the bolts & nuts. Like I mentioned in the other forum, the Magnaflow manifold/cats had a design flaw where one of the primary runners (tubes) was blocking access to tighten a bolt. Magnaflow was notified of the issue. Since this was noticed by a SS XC90 member this year or late last year, you may have old stock/inventory of the old design.

How did the shop handle this? Did the shop not install the bolt, did they cut the manifold flange, did they install a stud, did they hammer an exhaust manifold pipe, etc.? This doesn’t even include if there’s any unavoidable damage done to the downpipes/flexpipes.

These are under your ownership…if it’s your XC90. Since you’ve had it for a year now, it doesn’t matter what the past owner did or did not do. It’s up to you now.

Re-read past posts
Again, I’ll repeat, go over what has been written to help you in both this forum and the SS forum. Did you take pictures yet of the secondary catalytic converters, down pipes, decoupler seal area, vacuum pump seal area, read the spark plugs again, etc. None of these will be fixed using a 15W-40 oil. None.

I also mentioned in the SS forum thread you started months ago that you need to double check if your spark plugs are counterfeit. In your country, it’s probably a higher chance than the U.S. and we can still get counterfeit spark plugs from Amazon here.

You still haven’t smoke tested or double checked the intake tubes yourself, haven’t done the serpentine or cooling system work, read the Long Term Fuel Trims (LTFT) which is the fuel adjustment the computer makes with longer term data (baseline fuel adaptation), listed any other type of observations. The burning smell in the front, it could be oil burning from a leaky seal, it could be that you are breathing toxic carbon monoxide from a leaking exhaust manifold gasket, it could be the PCV spewing from its cap or gasket, etc.

Have you checked if you can see or smell any combustion gas leaking from above the exhaust manifold?

This is important
If you have the A/C on with the windows closed and there’s carbon monoxide leaking past the gasket, you could get poisoned from the gas. Don’t let anyone who is a child or someone pregnant ever ride in that vehicle until it gets fixed. Even if the windows are open.

This deserves repeating…
Most issues in the XC90 are from delayed or poor maintenance. Poor maintenance includes using cheap/bad parts or from not doing repairs correctly. You have to verify, not assume, each known maintenance part and repair.

[EgoziAlon]

Took out the plugs. For your judgment

[EgoziAlon]

More pictures

[chitownV]

#6 indicates your PCV (aka oil separator). Bad PCVs will start at cylinder #6 and then as it gets worse move towards both banks. In the Oil Consumption and P0420/P0430 thread I specifically linked to a thread showing this pattern.

You didn’t mention any observations while removing the plugs. Any oil in the spark plug holes? How are the coil boots? How do the spark plugs smell? Etc.

You kept on questioning my help and experience with the 3.2. The collective 3.2 experience that I reference in my threads are just the start so you can continue to research on your own. You assumed the cheaper PCV was good and then tried to justify why it’s not an issue. I hope it’s a good lesson for you to not make assumptions and to simply verify.

I think this is where I’ll end the my help in this thread in this forum. Now you can see to trust the process and the specific 3.2 threads directly addressing these issues.

Here’s one video on spotting a fake spark plug. You can search for more.

[EgoziAlon]

I didn't understand.
You are saying my pcv is bad?

[chitownV]

Re-read past posts thoroughly. Then read them again.
Thats all…..good luck.

[EgoziAlon]

I just smelled the no. 6 plug and it does smell like burned oil

[EgoziAlon]

I don't have much understanding in car parts resource when it is not on my language.
I really tried to send you all you asked for as much as i could and understand.
If you as a professional can give a conclusion of some kind as far as you see or tell me something specific to check then that will be the best.
I feel as if you are throwing at me a bunch of missions to do and i am not a mechanic so there is a limit to what i can do although i would of really wanted to.
Any way i will be happy for specific things to do or even go to a mechanic and ask from him.
What's the first few things you think i should do/check?