Suicide hose & catch can

I gather the main reason folk fit them is to prevent the engine's blow-by oil getting sucked into the turbo & getting baked on in places whee it is not desirable - ie. a means of keeping things clean & extending the turbo's lifespan.

Fitting a catch can wasn't something I had ever really thought about until I lifted my bonnet in the company of a couple of mates last weekend, both experienced diesel owners & mechanics, although not specifically with Patrols.

On opening the bonnet they both immediately commented upon the fact that I still had the 'suicide hose' fitted. I had no idea what they were talking about!

Turns out they were referring to the breather hose which goes from the rocker cover to the air inlet pipe between air filter & turbo. They explained that in certain circumstances, usually when giving the motor some welly up a hill, that it can become impossible to shut the motor off with the ignition key because the motor can continue to run on the 'blow-by oil, rather than diesel, after the fuel solenoid has cut off the diesel supply. Although rare, both claimed to have known of occurrences. When it happens apparently the only way to stop the motor is to block off air, not an easy task & fraught with the danger of injury as engine suction is extremely strong.

The suggested preventative solution was to fit a catch can mid hose to separate oil from air.

I have no reason to doubt what I was told, but in looking at catch cans I have seen no mention of reasons other than for engine cleanliness.

Nevertheless I have now bought one (a Provent 200 copy) & have spent this arvo making a bracket to hang it from.

Interested in any comments about what I was told.

Hmmm... dunno why you would want to shut off the engine in the middle of giving it a huge bit of welly up hill.

Once it is back at idle the blow by is usually quite low and the donk will shut off.

Diesels 'running on' certainly happens but I would think it is more likely a dodgy fuel cut or a very worn engine with lots of blow by at idle.

IMHO the best reason for a catch Can remains that of keeping the grunge out of the EGR system... but... would be happy to accept either as a good reason to fit one.

The way it was explained to me was that engine revs could potentially continue to rise & with no ability to turn off the motor revs could rise to the point of destruction, but I imagine that if this is possible it could only be with a very worn motor & a huge amount of blow-by

Seeings I've bought the catch can I guess I may as well fit it. If the EGR were also blocked would this be an issue?

That would be a lot of blow back. I have heard of this happening but usually a mechanical fault allowing fuel or oil into the intake. A mate told me of an occurrence years back on a cray boat when routine maintenance started the engine with the air intake pipe to outside the engine room, a bit like a snorkel, disconnected. Engine ran until someone covered the air intake. Brave man to under the deck to the engine room with a Perkins going off like that. Never heard the expression of 'suicide hose' though. As ET says, the best reason for a catch can is to try and keeo the intake clean.
This example off the internet.
https://youtu.be/Cqb7l-_P_nE

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Originally Posted by Cuppa

The way it was explained to me was that engine revs could potentially continue to rise & with no ability to turn off the motor revs could rise to the point of destruction, but I imagine that if this is possible it could only be with a very worn motor & a huge amount of blow-by

Seeings I've bought the catch can I guess I may as well fit it. If the EGR were also blocked would this be an issue?

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Cuppa, go ahead and install the catch can, its function is to filters out and retain the majority of the oil vapour that is vented from the engine crankcase.

The catch can will catch better than 98% of all oiley fumes entering the inlet manifold of your Diesel. A very good mod and you will be surprised how much oil it collects and IMO empty CC each oil change. I change my oil approx every 5000km.

After installing CC good idea to remove inter cooler, inspect for oil residue (oiley gunk deposit) give it a flush/dry to clean it (good idea if grotty). Have a look at your induction piping as well, some do inlet manifold justy depends how bad things are.


Whether the EGR is blocked or not, it is always beneficial to install a CC.

I hope your prevent copy is better than the 1 I originally got , the plastic was of poor quality & the lid never screwed on straight & wouldn’t stay on - I ended up making a ‘clamp’ type thing to hold it on , the filter was just stainless mesh - not a fibreglass wrapped looking thing as in the genuine Provent I now have .

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Originally Posted by Sprock

I hope your prevent copy is better than the 1 I originally got , the plastic was of poor quality & the lid never screwed on straight & wouldn’t stay on - I ended up making a ‘clamp’ type thing to hold it on , the filter was just stainless mesh - not a fibreglass wrapped looking thing as in the genuine Provent I now have .

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I'm hoping too!
Time will tell if the plastic is any good, but it feels solid enough. The lid feels like it screws on ok, has an o ring in it which seats at the end of screwing the cap on (when there is a final 'click' which feels like it 'locks' the lid into place). The filter is just stainless mesh which I'll wait to see how well it works, fabric wrapped filters are available *if* genuine Provent ones fit aftermarket copies.

This is the one I bought https://www.ebay.com.au/itm/Pro-200-...72.m2749.l2649

Anything thats makes the engine run cleaner and more effircient has to be good eg. blocking the EGR
I thought it was to keep the MAF a bit cleaner

Catch can has a few benefits Cuppa. Your motor will thank you for it.
I must admit that was the first time I've heard of blow by oil keeping a motor running away. But it makes perfect sense.
I have a Provent 200 ready to fit in. Been sitting on the bench for a while now. I'm in the process of finding some matching hoses, without bulky 25mm hose barb reducers.

I am keen to see where you have fitted yours. What bracket contraption you've come up with.

As some above have mentioned please be wary of imitation catch cans. There are varying degrees of "quality" of a copy. Keep an eye on yours.

Work friend had a provent copy on his 105 cruiser. It looked fine and dandy on the outside.
We sometimes use sump oil caught in a catch can to get a camp fire going, and that day we decided to empty his one out.
His one has a clear drain hose at the bottom of it. And inside the hose there were bits of black plastic fragments. When we opened the catch can we noticed the catch can has just about been eaten from inside out. This includes the outgoing hose barb. Meaning many plastic fragments ended up in the air intake post-filter.
Hence they're all in his crank case now .
It just seemed like the plastic it was made out of was not oil resistant. Could have been the heat too. Either way it wasn't good.
Same goes for hoses. Make sure the hose is oil resistant. On my 3L Patrol I had a hose from a XE Falcon heater with flared ends. It matched the 25mm catch can barb, and the 16mm motor side perfectly. Looked neat and tidy. After a while, I noticed oil drops from somewhere.
It turns out the hose was literally sweating the oil out, as the oil eventually made it's way through the skin of the hose.

Hi Hodge,
Unless I started moving other stuff around under the bonnet I really only had one choice of a place to put the can, on top of the passenger side wheel arch. It once had an aux battery fitted there, but I removed it so had that space. Without that space available I reckon it would have been too hard & I wouldn't have bothered!

I made a rather 'utilitarian' (ie. not pretty) mount from pieces of aluminium I had sitting around, glued (Soudal TRex) & riveted. Bolts to the wheel arch using two existing threaded holes & a third nut & bolt through a plain hole. I have demounted it for the time being until I have the hoses. I bought a couple of silicone hose reducers - for $24 which I'm waiting to arrive.
https://www.ebay.com.au/itm/AEROFLOW...72.m2749.l2649 The ad says 'not recommended for fuel & oil' but I reasoned that I have brass hose joiners so if I take care & cut the reducers accurately to length, little, if any, of the reducers will be exposed to any oil. I'll buy new 16mm oil hose. If I end up with a problem like you had with your heater hose I guess I'll grumble & cough up for a pair of Provent silicon hose reducers. I'll be keeping a close eye on the whole affair until I'm happy it is problem free.


Here's a pic of my "agricultural' mounting bracket sitting (not bolted) in position. Work of art eh? :D

http://www.nissanpatrol.com.au/forum...2018/05/72.jpg

http://www.nissanpatrol.com.au/forum...2018/05/73.jpg

Good job @Cuppa. You have ample room. My whole battery and DC-DC assembly is where your catch can ended up.
I only have one vacuum tank, at the spot where you have two. So thats roughly where mine will end up.

While we're at it ... Do you know / Have you measured the barb sizes needed exactly? I see you've ordered 25mm -> 16mm reducers.
Is the hose bar at motor end AND the air intake hose end the same? 16mm ?
I'm a little confused what size hoses are needed exactly.

You're so kind :D @Hodge . FWIW if I'd welded something up it would have looked even worse, would've needed painting, & weighed more into the bargain. :)

Yep, both 16mm (5/8"). I've only pulled the hose off the air intake side so far, but it's the same hose & has no flare at the rocker cover end.

I was a bit concerned that my brass hose joiners may have been too restrictive due to their wall thickness, but when I checked, their ID was identical to the ID of the barb on the intake.

Ah, so that's what they are - vacuum tanks. I thought they might be something to do emission control. Doh! Wonder why I have two when one is sufficient on yours?

The lid on mine wouldn’t screw on straight & would keep jumping over the thread no matter how carefully I tried to get it on straight so if yours screws on properly you’re off to a good start - they tell me the Provent filters fit he aftermarket copy cans but I turfed the whole lot out after a few months when the lid wouldn’t stay on & I wasn’t comfortable with the clamp contraption I’d made .

Those stainless mess filters are not worth a pinch of old cocky shit mate. When I was selling these years back I did a comparo of the mesh unit vs the original fibre filter. at 5000k the original filter would see 125ml of oil on average, I weighed the filter before and after too and noted the weight difference. Using the mesh filter, it only collected 35ml of oil on average and the weight difference was minimal...

@mudski Ok, got ya. A ton of old cocky shit aint worth much, let alone a mere pinch! I explained this to MrsTea who simply smiled & told me I should get a dinky di filter so have just ordered a genuine (79 buckeroonies - swoon) Provent filter element - fingers crossed it'll fit my filter housing ok or a bit more explaining to MrsTea might be in order.

Hahaha . By the way your bracket looks good 👌🏻

To wash out the fibre element I use petrol first, then hot soapy water. I found petrol the best to get the oil out of the element.

@Cuppa
I'm interested in what reducers you will be using.
I've just had a play with some reducers / hoses I've come up with in our diesel hydraulic mechanics work shop.
One issue I'm slightly concerned about is the internal hose joiners greatly reduce the internal diameter of the hose . So when a joiner is inserted inside a 16mm hose, the hose gains a 11-12mm internal restriction. If that makes sense.
Now I don't know what pressure this works under or whether or not this will be of any hindrance.
I've got the reducing kit pictured below at home but the joiners internal passage is 10mm at most.




http://www.nissanpatrol.com.au/forum...2018/05/80.jpg

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I've also found a hose that reduces internal size along the length . Designed for provent 25mm applications. So just cut where the hose diameter suits and you're set. A bit pricey though.

https://rover.ebay.com/rover/0/0/0?m...2F252254170757

http://www.nissanpatrol.com.au/forum...2018/05/81.jpg

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Originally Posted by Hodge

@Cuppa
I'm interested in what reducers you will be using.
I've just had a play with some reducers / hoses I've come up with in our diesel hydraulic mechanics work shop.
One issue I'm slightly concerned about is the internal hose joiners greatly reduce the internal diameter of the hose . So when a joiner is inserted inside a 16mm hose, the hose gains a 11-12mm internal restriction. If that makes sense.
Now I don't know what pressure this works under or whether or not this will be of any hindrance.
I've got the reducing kit pictured below at home but the joiners internal passage is 10mm at most.

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@Hodge Yep I saw that kit after I'd ordered my reducers. Probably the one I should have bought if I'd found it earlier.

I measured the ID of the connection to the air inlet hose & it was exactly the same as the ID of the joiners I have - (approx 11mm /12mm). The Provent is made to be used on a variety of motors,including bigger ones than ours with greater blow-by flow. As I understand it as long as any restriction is no less than the stock TD42 then we should be ok. I can't see any point in trying to fit 1" pipes as there will still be the 11mm/12mm restriction which Nissan use.

Quote:

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Originally Posted by Hodge

I've also found a hose that reduces internal size along the length . Designed for provent 25mm applications. So just cut where the hose diameter suits and you're set. A bit pricey though.

https://rover.ebay.com/rover/0/0/0?m...2F252254170757

http://www.nissanpatrol.com.au/forum...2018/05/81.jpg

Sent from Note 5 using TapaPro

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They are pricey because its oil resistant silicone. Well thye say it is so hopefully they are selling you oil resistant silicone. Normal silicone will deteriorate faster than rubber when it see's oil. I silicone at work, so I see this all the time.
Those hose clamps in the pic above Eric too will chew out the silicone hose, lined clamps is what should be used....
Attachment 75302

i used these for reducers...
Attachment 75303

Quote:

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Originally Posted by Hodge

@Cuppa
I'm interested in what reducers you will be using.
I've just had a play with some reducers / hoses I've come up with in our diesel hydraulic mechanics work shop.
One issue I'm slightly concerned about is the internal hose joiners greatly reduce the internal diameter of the hose . So when a joiner is inserted inside a 16mm hose, the hose gains a 11-12mm internal restriction. If that makes sense.
Now I don't know what pressure this works under or whether or not this will be of any hindrance.
I've got the reducing kit pictured below at home but the joiners internal passage is 10mm at most.




http://www.nissanpatrol.com.au/forum...2018/05/80.jpg

Sent from Note 5 using TapaPro

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Same joiners /bushes came with my Provent 200, works fine very low operating pressure and flow rate (restriction not a problem). Just been taking mine in and out over last couple of days fitted and adjusting actuator on stage 3 turbo and noted slight cracking at the larger dia of the reducer bush(all good though). For operating pressure, if interested, drain can open drain trap and put finger over end for indication.. My brkt made out of angle section cut from 150mm steel C-purlin (one leg longer in my case).

Your mechanics story has some credence - it's happened to me, though the circumstances were a little different.

My old Hilux sucked some water through a hole in Wombat back in the day. Pulled glowplugs, got it running again, bit smokey for a while but she was ok.

On the drive home stopped at Deer Park Maccas for a feed, came back out after a couple of McChickens and it's dumped a litre or two of oil on the ground.

Soaked it up with some rags, topped the oil up with the idea of limping it home. Turned it on, she fires up, then starts revving uncontrollably. Well above the redline.

Flick the key off, and she keeps going, revving as high as anything. Lucky for me it was a manual! Throw it in 5th, stand on the brakes and drop the clutch. She shut off. Last time that car ever ran :'(

Like it. Had an old swb cruiser put a B series diesel(4cyl) in it, had a mech injector pump pull cable to shut off fuel. In my case cable broke and had to stall her. Fun times..

@Cuppa, you must have a sixth sense or something.
https://bit.ly/2rJlftJ

I take no credit @4bye4, t'was my mates - both old school diesel heads.

@Cuppa

How did you go with yours ? Fitted yet? Operating? Catching much ?

I just fitted mine quickly on Friday before a quick run up to the high country with Mudski. Today I finished it properly with a bracket on the firewall.
I also found a grommet which perfectly the drain hose and sends it into the passenger front wheel arch tucked away for draining purposes.

I've done just under 600km after fitting and it has caught not a hell of a lot. Incoming hose is a little bit misty on the inside but thats about it.

http://www.nissanpatrol.com.au/forum...id=75345&stc=1http://www.nissanpatrol.com.au/forum...id=75346&stc=1http://www.nissanpatrol.com.au/forum...id=75347&stc=1http://www.nissanpatrol.com.au/forum...id=75348&stc=1

Don't know how long that hose will last with stones rocks and mud being thrown it's way?

Quote:

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Originally Posted by Hodge

@Cuppa

How did you go with yours ? Fitted yet? Operating? Catching much ?

I just fitted mine quickly on Friday before a quick run up to the high country with Mudski. Today I finished it properly with a bracket on the firewall.
I also found a grommet which perfectly the drain hose and sends it into the passenger front wheel arch tucked away for draining purposes.

I've done just under 600km after fitting and it has caught not a hell of a lot. Incoming hose is a little bit misty on the inside but thats about it.

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Neat job! I'm still waiting for the hose reducers to arrive, so have only bolted the can into place. I just ran the collection hose over the wheel arch & down to the bottom corner of the radiator. Not as aesthetically pleasing as yours but easy to see & access & no holes cut. I did 'chicken out' & ended up buying a genuine Provent filter element. Fits into the Provent copy can ok. I thought it would just be a stainless mesh with a fabric surround, but not so. The fabric filter material has no stainless mesh inside it & is quite thick.

Was talking to jack this morning, he's going to fit one too & plans to use the screw in hose reducers which will look really neat, but not sure how they would be for long distances on corrugations. He is getting a genuine Provent can, possible that the plastic may be better quality than mine & that it will hold the tapered thread better??? If his hold in ok I may yet copy him. :)

Quote:

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Originally Posted by Throbbinhood

Don't know how long that hose will last with stones rocks and mud being thrown it's way?

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Did think about that.
I think It should be fine. I used pretty much identical setup on my 3L. It's been on the car for nearly 5 years now and it's copped everything from the wheel and not had issues.

http://www.nissanpatrol.com.au/forum...id=75349&stc=1

I had my catch can in place for about 12 months, it works very well, I reckon I would catch about 50-100ml of oil every 5000kms.

I've done a shifty and cut the hose that leads back to the turbo, blanked it at the turbo and the other end just feeds out to the atmosphere. The catch can is still in place & catching as much oil as it always did. I no longer get oil mist into the intercooler and there is no sign of oil at all out of the atmosphere end of that catch can hose. I've also removed the rubber ring around the catch can lid so it doesn't seal 100% just in case pressure needs to be let out, even though those Provent CCs are meant to have a pressure relief valve in the lid.

@Cuppa
How did you go with yours ? Fitted yet ?

Mines been in for about 4-5 weeks now and it's caught nothing.
Opening the lid gives off a definite oil smell and it is misty / oily a tiny bit inside .. but no liquification or drops in the deposit tube.

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Quote:

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Originally Posted by Hodge

@Cuppa
How did you go with yours ? Fitted yet ?

Mines been in for about 4-5 weeks now and it's caught nothing.
Opening the lid gives off a definite oil smell and it is misty / oily a tiny bit inside .. but no liquification or drops in the deposit tube.

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PM sent Hodge

Catch cans and why they're a good idea. https://www.youtube.com/watch?v=T-B4VRxAtbw