Hi i've got a bit of a problem. I've got an 02 jtd with 59k on the clock and its getting a lot of oil in the MAF. I cleaned the old MAF but it appeared to be creating a problem so I bought a new one and fitted it. I noticed the oil when fitting the new MAF. it appears to be carrying over from the rocker box breather to the air filter then into the MAF. Is there a filter in the crankcase breather system that would block and cause oil carry over? I am obviously getting smoke from the exhaust due to oil being taken through the air system. Any thoughts?
Technical stilo 1.9 jtd oil in maf
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Technical stilo 1.9 jtd oil in maf
There is an oil trap in the airbox, it gets a might mucky in there and the best thing you can do IMHO is take out the airbox (a pain) and clean it all out. It's one of those things that probably should be done at every service 
You could disconnect the breather pipe and put an oil catch tank of some kind in the 'loop' or simply disconnect the breather pipe completely - but that's cheating
You could disconnect the breather pipe and put an oil catch tank of some kind in the 'loop' or simply disconnect the breather pipe completely - but that's cheating
The vapour trap is on the underside of the air-filter and (conveniently ) often parts company with it (which means you don't need to remove the air box at all).
You may find it's full of oil.
Oil can only arrive from the turbo and, as you say, from the breather pipe but there's no way for it to come from the air box.
) often parts company with it (which means you don't need to remove the air box at all).You may find it's full of oil.
Oil can only arrive from the turbo and, as you say, from the breather pipe but there's no way for it to come from the air box.
It will draw oil from the airbox - albeit not gallons of the stuff but it will get to the MAF I have asked the question a couple of times of Fiat mechanics and at my local garage and been assured that it can/does happen.
As the breather gases are 'exhausted' into the airbox there is only one place that oil on the MAF can come from and that's the airbox (excepting catastrophic turbo failure, in which case oil in the airbox isn't a prime concern!).
I was amazed at the amount of oil that had built up in the airbox of my JTD (found out when the GSR kit was fitted)....... but having since reverted to conventional induction I took the opportunity to clean out the airbox completely and maintain that physically removing it and cleaning it out is worthwhile.
In my case that's been at every service since reverting to standard induction, which has seemed appropriate timing to me.
I have asked the question a couple of times of Fiat mechanics and at my local garage and been assured that it can/does happen.As the breather gases are 'exhausted' into the airbox there is only one place that oil on the MAF can come from and that's the airbox (excepting catastrophic turbo failure, in which case oil in the airbox isn't a prime concern!).
I was amazed at the amount of oil that had built up in the airbox of my JTD (found out when the GSR kit was fitted)....... but having since reverted to conventional induction I took the opportunity to clean out the airbox completely and maintain that physically removing it and cleaning it out is worthwhile.
In my case that's been at every service since reverting to standard induction, which has seemed appropriate timing to me.
How can oil get into the air box (unless you're driving into the stuff ).
It's true, the vapour trap is part of the air-box and might give the impression that oil (or oil vapour) can somehow enter the air box directly but I'm pretty certain it can't. Be a pretty stupid system to feed oil vapour directly to the intake side of the air filter and MAF anyway :chin:
The only entry point for oil into the air-box is through the MAF assembly and even then it would contaminate the air filter first (the MAF sensor would of course be soaked with oil by this time and most likely ruined).
(unless you're driving into the stuff ).It's true, the vapour trap is part of the air-box and might give the impression that oil (or oil vapour) can somehow enter the air box directly but I'm pretty certain it can't. Be a pretty stupid system to feed oil vapour directly to the intake side of the air filter and MAF anyway :chin:
The only entry point for oil into the air-box is through the MAF assembly and even then it would contaminate the air filter first (the MAF sensor would of course be soaked with oil by this time and most likely ruined).
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ive just fitted the gsr kit i got from abzstilo and when i took the standard induction of theres was loads of oil in the pipes on the intake side of the turbo and down to the catch tank, but the filter was perfectly dry but the maf was also caked in oil.
I would think you have a problem if the maf is caked in oil, have you got a pic of the maf covered in oil.
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I agree
My MAF has never been soaked with oil in 4 years of ownership.Normal to see a fair bit of oil at the turbo end though and of course in the vapour trap (or oil catch tank if you prefer)
Bizarrely, you also get a lot of oil on the outside of the turbo/intercooler pipe
I'm intrigued....I'm not being funny, but how many times have you had the MAF out to see if it's got oil on it or notI agree
Each time my MAF has been changed (and that's several times) there's been oily residue on the outside of the sensor (before the delicate/expensive bits) but it wasn't drowning in the stuff - different folks, different definitions.
I'd be willing to suggest that nearly all JTD Stilos that run the same set up (so that is all of them, I guess) will have some oily residue/build up on the MAF that would surprise their owner when they saw it.
I could be wrong....... ofcourse.
Aye, I'd noticed that too. I wonder if all of this oil around the place is designed to stop things seizing up so that mechanics can change expensive bits more easily
To be fair, every TD engine I've worked on has always tended to be oily/dirty when you get to the complicated bits - no reason to assume an oil burner in a car should be any different I suppose
Hamish, The first time I did this it was by the book i.e. I removed the complete MAF assembly. I certainly wouldn't say it was coated in oil although the gauze filter (which I think is on the turbo side) showed signs of collecting a few bits of foreign matter.I'm intrigued....I'm not being funny, but how many times have you had the MAF out to see if it's got oil on it or not
Ever since, I've used a 5-star tool to remove just the sensor itself (hell of a lot quicker that way
) and I'd say on every occasion it's been spotless.I've even tried cleaning it on occasion, for the sake of it, but can't say its ever made any difference.
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another point to note argo is that my iduction setup is different to your 115 jtd and is a hybrid between the stilo and the GP induction, so shares the same MAF as the GP but has the air box of the stilo but then has different breathers to both of them
john55
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The EGR valve not function correctly or being blocked off will cause oil to be splashed onto the MAF. All diesels naturally get some oil into the inlet manifold so dont worry that it is there.
The smoke will be caused by the incorrectly reading MAF, not the small ammount of oil in the inlet.
On a JTD, the MAF is located rather close to the breather pipes so can easily get oil splashed on it due to changing pressure in the inlet pipe, often caused by the EGR is not working correctly.
The smoke will be caused by the incorrectly reading MAF, not the small ammount of oil in the inlet.
On a JTD, the MAF is located rather close to the breather pipes so can easily get oil splashed on it due to changing pressure in the inlet pipe, often caused by the EGR is not working correctly.
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Hi I'm back again. I dismantled the MAF and pipework and found it to be dripping with oil. There was carry back to the filter too. The oil appeared to be coming from the breather pipe from the rockerbox although I have just read that the oil can be caused by the EGR valve malfuntioning. Its my sons car and the oil in the intake has made it very smokey. We have cleaned all of the airways except the actual inlet manifold now and replaced the MAF. The engine now seems to hunt when the engine is on light load e.g when cruising at about 2000-2500rpm, when you put your foot down the fault goes away and the engine has loads of power but still smokes heavily which I thought was residual oil in the system. Could this be caused by the EGR val sticking and would it go away if I cleaned it?
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How does that work then? The EGR valve recirculates gas not oil infact oil goes nowhere near the EGR. If the car is smoking badly it's burning oil meaning something else internal in the engine must be wrong eg valve stem seals or piston rings leting oil up from the sump
My thoughts exactly
I know that a stuck open EGR will slow the turbo from spinning up (due to lost exhaust flow to the turbine) but even that still means the oil must makes its way all the way from the inlet manifold, through the intercooler and back to the MAF (which is ALL in the wrong direction)
I think you're right that this engine has suffered severe wear since, as already said, oil can only come from either the breather pipe or the turbo (either of which is bad news
)john55
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ebay. When mine went, I got a reconditioned one that someone never got round to fitting very cheap. It is the same as the Multipla JTD turbo.
It is unusual for a turbo oil seal to fail at this low mileage, also you say it is stuttering at about 70mph, on light throttle. That is classic EGR valve sticking symptoms.
What colour smoke do you get? A turbo oil seal failure will give clouds of light blue/ greyish smoke. If it is black smoke then oil seal is not your problem.
john55
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No. The EGR when open vents the inlet manifold to the exhaust pipe so the pressure created by the turbo is lost out the exhaust pipe. The turbo is still working normally.My thoughts exactly
I know that a stuck open EGR will slow the turbo from spinning up (due to lost exhaust flow to the turbine)
The rocker cover breather pipe enters the inlet just before the turbo and just after the MAF. It can not enter the high pressure pipes after the turbo.but even that still means the oil must makes its way all the way from the inlet manifold, through the intercooler and back to the MAF (which is ALL in the wrong direction)
No it wont be suffering from wear.My thoughts exactly
I think you're right that this engine has suffered severe wear since, as already said, oil can only come from either the breather pipe or the turbo (either of which is bad news
A little oil normally comes through the breather pipe. It is quite normal in any Diesel engine, and gets burnt harmelessly in the engine. Oily intercooler and inlet pipes are quite normal.
I doubt his turbo is the problem either as it seems to be working, and when oil seals go on a turbo it is because the bearings fail and the impellar stops spinning.
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how do you know it wont be suffering from wear?
we were just saying possible causes from the symptoms the OP had given.
i agree oily intake pipes are normal in diesels but even so there are limits.
if you doubt its his turbo and say there isnt any engine wear, where do you think the smoke is coming from?
having worn engine internals can cause smoke just as much as a buggered turbo tbh.
