have a look on here there are a few pics of catch tanks inline and one venting to atmosphere through a small filter(intake fitting would require blanking)
http://www.seatcupra.net/forums/showthread.php?t=217342

muppet, hope this answers your question. i dont think the air that goes into the turbo is cooled. its the air that comes out of it is cooled. i beleive it is this way around because when the air is compressed in the turbine it heats up. so the air is sucked in through your nice filter (what are the power gains like after fitting that, does it feel quicker?) into the turbo, compressed via the turbine and pump out of the outlet part of the turbo, into the intercooler which works in the same way as the radiator but cools air instead of water and then the ait goes into the engine.

this diagram should help. its what helped me understand it

http://www.team3s.com/Images/tintt2.gif



as fot the ctach tank....

Originally Posted by Stuart_89
i dont see how the oil trap would work well... because my 8v JTD has the pipe going from the oil breather pipe on the engine cover going into the pipe that goes straight into the trubo, so wouldn't the turbo suck it all in before any oild falls into the trap?

That's extremely valid but at some point you just have to trust the engineers that designed the JTD aren't stupid. I'd imagine Alfa use a very similar system.

If you look carefully, the outlet to the oil trap is directly opposite and underneath the crank breather pipe (the diagram looks a little wrong to me) so it's easy to imagine oil being blasted across the path of the incoming air stream but what happens under say full boost is another matter :chin:

Like I say, you just have to take some things on trust. You don't hear of too many turbo failures (even when mapped) so they must have got something right

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would fitting a catch tank just double the effectiveness of catching the oil. i.e feed a pipe from oil breather pipeto catch tank and other line to little join on the turbo pipe. because this will hopefully filter out the oil but if any gets throught the oil trap would catch the rest? it would give a little better protection at full boost possibly?

worth a try maybe?

so the vented ones just have a pipe from the oil breather pip and vapours are vented to the atmosphere, i.e no pipe going to air intake? but a few on ebay have two pipe holes and a filter...

No i know thats the oil catch tank, What i was getting at was this now i have looked at it,

What i couldnt understand was the intercooler setup on these jtd's, But now i realise that the EGR gasses are passed out through the intercooler and back into the turbo and mixed with whatever air comes in the filter, Which seems a odd way of doing it or do all modern td's do this now. I must admit it was kinda the same idea on the escort but i ran it with the egr blanked off.

But if you were to blank the egr off in a jtd then surely no gasses would be passed through the intercooler and therefore running on fresh air??????

Unless someone knows better than me, then is this set up not the best.???

Muppet1 said:

No i know thats the oil catch tank, What i was getting at was this now i have looked at it,

What i couldnt understand was the intercooler setup on these jtd's, But now i realise that the EGR gasses are passed out through the intercooler and back into the turbo and mixed with whatever air comes in the filter, Which seems a odd way of doing it or do all modern td's do this now. I must admit it was kinda the same idea on the escort but i ran it with the egr blanked off.

But if you were to blank the egr off in a jtd then surely no gasses would be passed through the intercooler and therefore running on fresh air??????

Unless someone knows better than me, then is this set up not the best.???

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You must have an oddball Escort there muppet because that's not the way the JTD is designed

If you start at the exhaust then most of the kinetic energy in the flow is used to drive the turbo. The business end of the VGT turbo dynamically provides anything from zero to max boost pretty much on the fly (with control being provided by the overboost valve) and the rest of the process follows Stuart's description. This design is the key reason the JTD115 suffers from such little lag.

However, before the turbo, some of the exhaust flow is piped away, cooled (can't remember if it's water or air cooled) and fed to the EGR valve.

The best way to think of the EGR valve is a means of reducing the cubic capacity of the engine (although it does other stuff). Once the valve feeds a measured amount of what is basically an inert gas into the manifold then it follows that LESS air will pass the MAF sensor to make up for the requirements of the inlet stroke. This leads to a lower fuel requirement which in theory at least should prove better mpg and less pollution.

Now consider what happens if the EGR valve sticks open. Notice that not only are exhaust gases being fed directly to the inlet manifold but there's also less flow to the turbo - which explains why a defective EGR can have such an effect on performance. It also explains why it's only necessary to blank off the EGR to prove if it's faulty or not.

Notice there's no connection between the intercooler and the EGR valve at all!

impretty sure my egr gas cooler is water cooled and i think it doubles up as a heat exchanger working the other way round when first started, with the exhaust gas temp helping to warm up engine temp through this heat exchanger water going back to block.engine gets warmer sooner and is efficient sooner.
regards fitting a second catch tank,as good as the seperator may/may not be that fiat have fitted i would regard it as very small for what its trying to do,it looks like it could seperate the liquid oil from airflow fair enough but looks like it has no chance of letting oily vapours condense/settle out before passing on into inlet pipe(purley based on volume, no idea of internal design of fiats seperator)
had seen a good pic of someone emptying out their catch tank,if i can find it i,ll stick it up.

just part way through todays job,cleaning k+n,maf and pipework breather pipes etc.the vapour trap pipe below filter box had black oil dripping out of of when removed from trap trap wasn't too bad but could see the shine of oil in there.got to be ru nning down from breather pipe or turbo seal maybe?

sussexa said:

just part way through todays job,cleaning k+n,maf and pipework breather pipes etc.the vapour trap pipe below filter box had black oil dripping out of of when removed from trap trap wasn't too bad but could see the shine of oil in there.got to be ru nning down from breather pipe or turbo seal maybe?

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Your set-up sounds identical to the JTD115 and finding a fair covering of oil is I'm sure completely normal.

I'd imagine the source of oil will be the breather pipe with a good proportion being drawn into the turbo housing (as you'd expect) which gives the impression the oil is leaking from the turbo.

...but did you not say on the mJet that oil is returned to the sump

I know it's an older vehicle and petrol but you may find
the page of interest.
http://www.lotuscarlton.co.uk/oilcatch.htm

John

all back together now, anyone attempting taking all these hoses off i suggest you have some new jubilee clips ready in case you cant get the originals back on the larger ones i managed to refasten using long nose pliers but the smaller ones i've had to fit jubilee's.
managed to get finger tips to tubo spindle end and had a feel of freeplay for future reference.
argo it wasn't much oil and yes the oil seperator tank returns most of the oil back to sump but having seen inside now its not very big volume wise i could see no pcv valve either but the oily fumes will still travel down to inlet pipe and you will see on pics after that the design of the pipe would let the oil settle in the bottom of the bottom of the inlet pipe and won't allow it to dribble into vapor trap pipe as it stands proud by 5mm or so of bottom of pipe.

heres inside turbo inlet pipe showing vapour trap pipe at bottom and breather pipe coming in at the side, see how much pipe protrudes any oil will well up in bottom of inlet pipe rather than run down into vapour trap(unless it luckily falls into pipe).

heres some oil dripping out of bottom vapour trap pipe.

heres pipework getting cleaned in solvent.

heres the turbo inlet supprised how clean it looks.

actually looking at pic now i can see a line of oil top right hand corner which would be at the bottom(pic is side on)this must have run in from inlet pipe.

You've just proved me completely wrong about the pipe positions

They're not opposite as I thought but exactly as yours is shown although when I examined mine I never noticed that it protruded within the housing.

Mine is at such an angle that it looks like oil would drip directly directly into the vapour trap pipe. You've made me wonder now if that's correct or should the outlet to the vapour trap be positioned underneath i.e exactly vertical. :chin:

mine has a small dowel on the turbo body that aligns in a small cut out in the rubber inlet pipe to keep it all aligned.
i think its the dowel shown in the turbo pic on page 2 at top right corner of turbo name plate(unless theres more than 1)

I think you're right about that although I must admit I failed to notice when taking mine apart.

Certainly everything 'feels right' at a certain position.

Did you have fun cleaning all the oil off the intercooler ducting - now that's a lovely dirty job getting all that clean :yuck:

wasn't too bad really,had picked up a 1 litre tub of solvent/degreaser from aldi or lidle a few weeks back, and just poured it on and worked with a paint brush where possible and a couple of pieces of rag as a pull through for the pipes ended up using about 1/3 of tub then just hosed through with water and shook dry.

any oil will well up in bottom of inlet pipe rather than run down into vapour trap(unless it luckily falls into pipe).

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actually looking at pic now i can see a line of oil top right hand corner

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when i changed my air filter i noticed there was a bit of oil in the inlet pipe going into the turbo. i wouldn't imagine it would be loads but i think fitting an oil catch tank would be interesting to see how much it does collect.

sussexa if you ever fit yours coment back to let us know how it goes... i might get my mate to coble a small one together if he has the time.

Stuart_89 said:

when i changed my air filter i noticed there was a bit of oil in the inlet pipe going into the turbo. i wouldn't imagine it would be loads but i think fitting an oil catch tank would be interesting to see how much it does collect.

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I can't see it being much

I've yet to add any oil to my JTD from one oil change to the next :spin:

I've yet to add any oil to my JTD from one oil change to the next

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good point.

but if the catch tank were to collect all of the oily residue before it goes into the air inlet then it would be easier to keep the inlet pipes & throtle body etc cleaner.

hey,

you might just be the right person for the answer that i need!!!! in the middle picture, the pipework picture could you tell me where the smaller pipe fits to???? i noticed that that pipe has broken off and on numerous occasion i've been trying to find where it fits to with no luck, or if you were able to send a picture from the underneath would greatly appreciate.

thanks,

ANDRIUS

if your talking about the pics in post 30# its the pipe from the breather system in my case it goes to a metal section of pipe that passes over the engine and then goes to rubber again to join on the oil seperator at the rear of the engine, on the 8v jtd i think it joins onto the rockerbox breather ?.
see back to post 6# on page 1 its pipe 11.

JTD Turbo Hose

Hello!

Can anyone tell me what does the hose marked in red in the picture? The hose is connected to the thicker hose that connects the air cleaner and turbine. The hose is stopped at an end and is pulled up.

The car runs normally and the turbine operates normally. The engine is 115 JTD

Please help me...