Oil Catch Cans - another danger...

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FlyPenFly

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From the B8 A4 Audi forums:

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Blew RMS, upper timing cover gasket, VC gasket and catch can gasket on VC. Emptied my catch can yesterday, but seems like there was some water that froze in the line last night. Going back to the factory PCV setup.

Happy Monday!


These things have almost no impact on intake valve deposits on DFI engines. No reason to run them, and probably a really good reason NOT to run them. The RMS on these engines are super hard to get to..

$1,500 in repairs caused by a useless system
 
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We don't know their exact setup and we don't know if it appeared to be the catch can but was actually something else. I wouldn't trust a forum without seeing it first hand or having the whole story.

I've seen plugged PCV's before and it will either force the dipstick out of the tube or pop the PCV/hose off and cause 0 issues with seals on the engine.

It's super cold here right now, I'll let you know if my engine encounters the same fate.
 
The VW/Audi 2.0L DFI engines are known to lose RMS when the PCV system fails. Probably should be a regular maintenance Item every 30k miles or so to change it. The assembly can be had from $42 on a Chinese knockoff up to about $100 for an OEM. Catch can freezing if full would mimic a bad PCV in some cases.
 
Originally Posted by sloinker
The VW/Audi 2.0L DFI engines are known to lose RMS when the PCV system fails. Probably should be a regular maintenance Item every 30k miles or so to change it. The assembly can be had from $42 on a Chinese knockoff up to about $100 for an OEM. Catch can freezing if full would mimic a bad PCV in some cases.

And this would be the "More to the story" part. I'm not saying that a frozen PCV breather line isn't cause for concern but that it usually results in popping off the line, popping out the PCV valve if it's the push in type or pushing the dipstick up the tube so it can breathe is all. Not great but not catastrophic like this case above which is more of a design fault that the frozen PCV line helped along.
 
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Originally Posted by StevieC
Originally Posted by sloinker
The VW/Audi 2.0L DFI engines are known to lose RMS when the PCV system fails. Probably should be a regular maintenance Item every 30k miles or so to change it. The assembly can be had from $42 on a Chinese knockoff up to about $100 for an OEM. Catch can freezing if full would mimic a bad PCV in some cases.

And this would be the "More to the story" part. I'm not saying that a frozen PCV breather line isn't cause for concern but that it usually results in popping off the line, popping out the PCV valve if it's the push in type or pushing the dipstick up the tube so it can breathe is all. Not great but not catastrophic like this case above which is more of a design fault that the frozen PCV line helped along.


Wonder if this engine doesn't have a dipstick? Many of these "advanced" vehicles have electronic oil level indicators.
 
Originally Posted by OVERKILL
Originally Posted by StevieC
Originally Posted by sloinker
The VW/Audi 2.0L DFI engines are known to lose RMS when the PCV system fails. Probably should be a regular maintenance Item every 30k miles or so to change it. The assembly can be had from $42 on a Chinese knockoff up to about $100 for an OEM. Catch can freezing if full would mimic a bad PCV in some cases.

And this would be the "More to the story" part. I'm not saying that a frozen PCV breather line isn't cause for concern but that it usually results in popping off the line, popping out the PCV valve if it's the push in type or pushing the dipstick up the tube so it can breathe is all. Not great but not catastrophic like this case above which is more of a design fault that the frozen PCV line helped along.


Wonder if this engine doesn't have a dipstick? Many of these "advanced" vehicles have electronic oil level indicators.


On the B8 A4, and I imagine others, it comes blocked off but it's simple to get a dipstick in there instead.
 
Originally Posted by FlyPenFly
Originally Posted by OVERKILL
Originally Posted by StevieC
Originally Posted by sloinker
The VW/Audi 2.0L DFI engines are known to lose RMS when the PCV system fails. Probably should be a regular maintenance Item every 30k miles or so to change it. The assembly can be had from $42 on a Chinese knockoff up to about $100 for an OEM. Catch can freezing if full would mimic a bad PCV in some cases.

And this would be the "More to the story" part. I'm not saying that a frozen PCV breather line isn't cause for concern but that it usually results in popping off the line, popping out the PCV valve if it's the push in type or pushing the dipstick up the tube so it can breathe is all. Not great but not catastrophic like this case above which is more of a design fault that the frozen PCV line helped along.


Wonder if this engine doesn't have a dipstick? Many of these "advanced" vehicles have electronic oil level indicators.


On the B8 A4, and I imagine others, it comes blocked off but it's simple to get a dipstick in there instead.


thumbsup2.gif


So they make one that can be fitted? I believe, and I could be wrong, that some BMW's don't even have a provision for it, you are supposed to use the EOLS.
 
Originally Posted by OVERKILL


thumbsup2.gif


So they make one that can be fitted? I believe, and I could be wrong, that some BMW's don't even have a provision for it, you are supposed to use the EOLS.


The tube is still there, but it's plugged. You can buy the dipstick and remove the plug if you want. Takes 30 seconds.
 
Originally Posted by Jimmy_Russells
Originally Posted by OVERKILL


thumbsup2.gif


So they make one that can be fitted? I believe, and I could be wrong, that some BMW's don't even have a provision for it, you are supposed to use the EOLS.


The tube is still there, but it's plugged. You can buy the dipstick and remove the plug if you want. Takes 30 seconds.


Not a bad setup then.
 
I was wondering about freezing,,, maybe as Stevie collects all the material and saves it for a year, he can freeze it and see what happens. I'd suspect the freeze point does change a bit...
 
Originally Posted by sloinker
The VW/Audi 2.0L DFI engines are known to lose RMS when the PCV system fails. Probably should be a regular maintenance Item every 30k miles or so to change it. The assembly can be had from $42 on a Chinese knockoff up to about $100 for an OEM. Catch can freezing if full would mimic a bad PCV in some cases.


I want to say it is FCP Euro has an updated RMS that is supposed to fix the issue.
 
Originally Posted by JHZR2
I was wondering about freezing,,, maybe as Stevie collects all the material and saves it for a year, he can freeze it and see what happens. I'd suspect the freeze point does change a bit...

I'm going to leave a bottle of collected fluid out in the cold for a couple days for demarpaint to see what happens... I'll report back.
 
This specific failure seems to be caused right after emptying it. It seems that there is increased water vapor concentrations with the catch can setup. When emptied there is no oil to stop freezing.
 
Originally Posted by FlyPenFly

These things have almost no impact on intake valve deposits on DFI engines. No reason to run them.


What he said.
 
I'm interested to see (as stated in my thread) what it catches over the course of a year. I would also like to do comparative UOA's to see if it has any effect on the lubricant. (For fun, not saying it's required)
 
Originally Posted by Patman
Catch cans are a waste of money, and here's yet another reason to avoid them.


Ever notice that most of the people extolling the virtues of catch cans on internet forums are usually involved with the sale or manufacture of catch cans? Yes, people install them and collect "stuff" in the can. Big deal. That same stuff would pass through the engine intake tract with no ill-effects like it has for years if you weren't forcing it to condense in a can.

Cans don't address the other source of oil contamination on intake valves. Valve stem seals always have a controlled leak so that guides stay lubricated. With vacuum in the port, where does that oil go? How ya' gonna trap that stuff?

We ran a GDI turbo 2.0 Ecotec regal well beyond 100k miles with no "necessary" catch can, and it ran like new when we traded it. As OP indicated, they can cause more problems than they solve (not to mention making your wallet lighter).
 
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