One catch can - Or two ?

the best way is to have the ecu mapped and while in there get any codes that its likely to throw up by fitting a catch can off self check as the pcv is all part of the emissions on that engine so maf and map sensor will feel any changes as a rule, ie if breather pipe and catch can restrict the flow in anyway or if it opens it up as its all part of the whole engine system that bmw/psa spend millions on getting it to run at a eco friendly level, needs doing right i have seen many people follow utube links and some random unqualified person messes around with it and gets it to run sort of but never reposts with what has happened 10k down the road ie engine killed off from lack of balance within the combustion chamber ie pinking or knock those turbo engines run on whats just about possible for 100k maybe. and just changing anything that will effect how it ignites each power stroke really is based on some luck. where correct way is to have it mapped with all the mods you want, ie can delete the pcv run a straight catch can can run a better inlet filter panel or big cone can also put a sports cat ie less honeycomb in it then through a big bore exhaust could even go to next level hybrid turbo and bigger injectors etc all these can be programmed in to work correctly and also will pass a mot of emissions, this all sai for what it all costs you only need a good remap maybe include a louder air filter in to of thats what you like etc will see over 200bhp easy on a eco map a lot more on a power map, in my signature black magic timing can either do a mail order ecu only rema ie generic with anything you want deleted or better way book in and have a day out get him to bespoke map etc, just mention me off here he will give a discount when people do,, just a heads up hes the guy other garages go to when they have a faulty car that beats them he's not just a mapper anyone can flash a ecu he's proper tech as well.
done a vauxhall 2,0 cdti the other day they run high pressure glow plugs that are for emissions not for starting the car really, had it dpf gone and egr and remap from 130 to 160 ish eco map he also removed the glow plug codes from ecu as dont need them ie new glow plugs are £136 each and not needed on a mod like this, funny a ecu repair company argued this could not be done impossible he said as self check would find it, hmmm car has been driving around perfect a far while now so much better, my point is these things need to be done by the right people otherwise 10k or 20k down road the damage could be done even more of a risk on a car that has been changed based on non qualified advice

Mr.Whippy said:

OK chaps - just getting to grips with my new (to me) 2008 Cooper S.

Had it a week, now It's in bits (not because it's faulty, because I want to renew the timing chain and do a few other jobs), one of which is to walnut blast out the inlet ports and fit a catch can to the hose which goes from the rocker cover to the turbo inlet.

Now my question is - there's a second breather hose (PCV ?) from the back corner of the rocker cover. My thinking is that this will also recirculate oily fumes back into the inlet so surely this pipe should also have a catch can plumbed in if I am to prevent the inlet valves from gunking up once again ? I see plenty on here and on youtube vids showing one catch can, is there a good reason that people only fit one and not two ?

Cheers - Dave.

Click to expand...

I would only recommend using oil catch cans if you're sure the engine has no problems.

2 catch cans would be better at delaying the carbon buildup.

N14 engine people usually fit 2 oil catch cans and N18 just the one oil catch can.

If you check on their website, it'll give you a good explanation why 2 oil catch can is preferred


If you can walnut blast service yourself, I would probably say don't use any oil catch can and just walnut blast every 2 years or 20K or whenever the carbon buildup becomes a problem.

Thanks for your input chaps…..

Car was running fine, no error codes. It’s done 65000 miles and there’s no record of the timing chain being replaced so I’m doing that now for future peace of mind. It is an N14 motor.
Once I locked the flywheel it was obvious to the eye that the cams were starting to move out of time even before I fitted the cam locking tool so I am glad that I took the trouble now. The original chain guides are still in one piece although I’ll be changing them as well of course.

Whilst it’s in bits I thought I might as well blast the inlet ports clean and seeing as I’m going to the trouble of doing that I don’t want them fouling up again, hence the catch can(s) question. It is a N14 engine so yes, it does seem that I’m thinking along the right lines doing both vent tubes. I have done some online digging and found other reports of people running two cans.

Seems daft to me only fitting one catch can – it’s only going to fix half the problem as I see it – Might as well do both pipes or none at all. (just my 2p)

The main goal here for now at least is just to have a reliable car that drives well and where I can trust that the engine isn’t going to suddenly self destruct. – I’m not out to chav it up with shiny billet bling just for the sake of it. I might go for a stage 1 or 2 remap at some point in the future but in the meantime I’ll be keeping it stock, or close to stock.

Just bought a couple of these - https://www.ebay.co.uk/itm/Quality-...608852?hash=item2accbdac14:g:Ea0AAOSwyotc570n the pipes are 19mm diameter which is roughly right for the mini - there are cheaper catch cans on ebay but they have tiny narrow pipes so best avoided I reckon. Those GTT ones sure look the business but my budget is stretched enough at the moment, & I'm not bothered what it looks like so long as it works. My 2 catch cans plus some rubber hose & clamps should come in well under £60 so if I start getting any odd error codes or problem running then it will be easy enough to put back to standard again and I won't feel like I have been burned if I have to ditch them.

I already have a media blast gun and a compressor, just bought a bag of walnut shells. I will have to pull the manifold, take some measurements from the ports then fabricate an adaptor that will allow me to suck up the nut shells into the shop vac. It's going to keep me busy for a weekend or two...

Dave.

Just to update this thread -



Catch cans from ebay fitted with some 19mm rubber hose (car heater hose) - Homemade bracket holds both together. Have modded the cans with some additional baffling inside (fine stainless wire mesh wrapped around the inlet side) - and also drilled & tapped the tops and made some dipsticks from M8 stainless threaded bar.



It's a tight fit if you want to remove / refit the airfilter box as one unit due to the pipes but you can just about do it.

Have also cleaned out the inlet ports & valves - they were really heavily coated - My walnut blaster struggled to get them clean on it's own - I ended up doing a fair bit of scraping and spraying some injector decarboniser https://www.wynns.eu/product/injector-decarbonizer/ after spotting it in my local accessory shop. It seemed to soften up the carbon somewhat. I then had to rotate the valves 180 degrees to be able to fully clean round the other side. Alternating with scraping, spraying and blasting sorted it out in the end but it got very tedious.

Also removed the pipework from the turbo and cleaned all the oil out, also in the intercooler.

I also fitted a new thermostat as I had read that they were another common failure point - and it's a good job I did as although the old one had no leaks and there were no fault codes, the 'stat inside had failed in the open position.

Cam chain done, oil pump chain done, new exhaust sprocket. Vanos solenoid cleaned & refitted. No obvious bits in the oil strainer or bottom of the sump. Reset the vanos with autocom.

Had 2 error codes thrown up afterwards - one throttle actuator code and a rough idle - turned out a tiny fragment of walnut shell had jammed itself on the edge of the throttle butterfly stopping it from fully closing - picked that out and the fault cleared. My garage is now infested with walnut shell media - it gets everywhere !

Then on the first test drive I gave it a bit of gas and lost the turbo boost and got a 2885 code. Turns out I hadn't tightened the jubilee clips tight enough on the boost pipework and the hose blew off.

So all sorted, been driving it a couple of days now, running great.

Thanks for all the advice guys.

louisjlang said:

Hi! Reading this I am well impressed with the thorough work you've done! I have a quick query, as someone looking to do the same dual can install, how did you solve the issue of attaching pipework to the fittings on the inlet manifold and rear left of the rocker cover? I have seen people butcher old OEM breather pipes for fittings, but am curious as to how you have done it here as it looks very clean and neat!
Any advice would be amazing!
Thanks

Click to expand...

OK, thanks.

It's been a while since I did it but from memory it's all 19mm ID rubber braided hose, (not PVC, as the bends would kink PVC hose) and it's a pretty tight push fit onto the Mini OEM fittings. I haven't used any hose clips, didn't need to. I also bought catch cans with 19mm hose fittings to make it easier.- like these - Billet Aluminum Oil Catch Can Tank Bottle for BMW N54 Engine 500ml 19mm | eBay
I think the cans normally sold for the mini application have smaller hosetails so would then need adaptors either at one end of the pipework or the other ? - just makes sense to me to keep the pipework all the same diameter and keep it simple.

I also find that the easy way to empty the cans is to unscrew the dipsticks and suck out the contents with a Pela oil extractor, it's a 2 min job that way with no fiddling about and almost no mess.

Dave.