S3 Catch can effluent - What has my catch can caught this month?

warren_S5

warren_S5

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I decided to empty the catch can at the weekend and see what had been captured by the BSH system that would usually be clogging up the system had the PCV mod been fitted.

So I pulled out the can, emptied it, and got this little mess; a conglomeration of oil and water which on the face of it doesn't look to pretty (I appreciate without prior warning you could be forgiven for thinking I'd shat in a pot after a very bad night out).

P1000260.JPG


I'm not sure what to read into it really.

> Does it look so bad because the catch can system sits outside the engine, and normally any of this stuff would dissolve in the heat of the engine?

> Does the oil go this way just purely down to the fact its been sat in condensation for a while?

Not sure what to say one way or the other, and don't suggest this is a cue for anyone to rush out and buy one of these devices as I'm sure it is not as bad as it looks (4 weeks of catching, and 1000 miles of average journeys).

Be interested if anyone else on here has one to see if they are seeing any different.

Does anyone know if the PCV mod recirculates this stuff or allows the condensation/ water to escape meaning the oil doesn't congeal?

Answers on a postcard, and what a pleasure to be writing a relevant post for what feels the first time in ages :blush:
 
Interesting er...stuff you've got there!

I'd like to hear from others too.
 
Interesting thought process, would that have burnt up in engine anyway or would it clog, me also would like to know of others experiences
 
and for the record it stinks (not like sh1t), but it's really unpleasant smelling in really manky oily dank foul kinda way. Turns my stomach.

By the time I had poured it out and gone and got the camera it had settled a bit as the water was frothier and cloudier. This is what it settled to. This may be due to strainer holes at the head of the catch can though.
 
Obviously I don't have the knowledge of Forge, BSH or JonnyC (all of whom have a PCV fix of this kind) but I just can't find within me the need to worry about this.

Mitch78 has around 80,000 miles on his S3 and others have plenty over 50,000 miles - all with no problems at all. Engines are dirty places - and on these engines some gunk like this goes back into the manifold. It doesn't look good (or smell good) but is it worth worrying about ? If it causes harm surely someone with high mileage would have experienced a problem of some kind by now ? Then again maybe they have and I've just missed it.
 
Jonnyc car might not be a totally fair comparison? Wasn't his heavily tuned?
 
edition said:
Jonnyc car might not be a totally fair comparison? Wasn't his heavily tuned?
Click to expand...


it was, but it was quite low mileage (from memory).

any tuned car is pushing the parameters enough to accentuate the issues as the oil is worked harder, temps rise, the fuel may not burn as well etc...
 
It's not the same engine,but both of the relatively highly boosted cars I've owned before we felt it was mandatory to include an oil separator,plus crank and cam breathers,to ensure firstly that all of the crap isn't fed back into the induction system,but also that muck is pretty good at inducing preignition at high boost levels,which is the best route to holed pistons.

Both of those were 2L Cosworths,one running 2.5bar,and the other 2.5-3bar,reliably,without any problems over many thousands of miles.

Now I know from what S3BigAndy said,that he'd ended up with holed pistons on his GT3071 conversion,and I don't know if he had a separator on his,and JonnyC also bought his back after selling it,only to find the guy he'd sold it to hadn't even changed the oil,and had a holed piston into the bargain.

I think the rule is that with modified engines,you need regular oil changes,and a separator system.

Anyway Warren....yummy. :puke2:
 
Staz said:
Jonnyc had this:

From his build thread:
Click to expand...

That's the point though Staz - he had that despite having done the PCV mod very early on in the engine's life. I think it was the lack of a regular oil change which caused this - not the PVC business.
 
Last edited:
I think I misunderstood something then! I'll have another read of it when I get a chance...
 
im sure that car in its early life had jonnys 'pcv mod' in not the catch can i hope im getting this right, and the mod was the pcv completley blocked off with the breather facing down into the engine, now forge do a system for it and jonny is waiting for it i 'think'

or is that breather pipe the bit that dispenses the cr*p ? im not really sure
 
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