Technical Breather hose oil leak

[Martin Y]

Our (2010 1.2 Dynamic Eco) Panda has an oil leak which shows up as a burnt oil smell whenever a drip lands on the exhaust. Both the Y-shaped hose from the cam cover breather to the air box and the sealing ring between the airbox and throttle body had clearly been leaking oil. (The hose was split at the engine end, the ring was loose fitting, maybe swollen and damaged by oil).

Very easy to find replacement parts except both the parts I ordered turn out to be a really bad fit. So I'd really value some advice on how to identify better ones. The hose, for example, clearly looks like the proper part but the size is just wrong - the middle part of the s-shape is about 25mm too long so the two ends don't line up with the hose barbs and the bore size at the engine end is much too big. Being silicone it's squishy enough to just about clamp down on the hose barb but I doubt it'll seal properly. I can't tell if it's actually meant for a different engine or if it's just a really badly made copy.

The other question that's bothering me is why there's quite so much oil in the hose at all. I'd expect some oil mist coming out of the breather but this seems excessive. Is there some kind of baffle or series of chambers inside the cam cover that's meant to trap oil mist before gases leaves the breather? (There is in other engines like the Mazda BP I'm more familiar with.) I could take the cam cover off to check for myself but now I'm paranoid the cam cover gasket I bought will turn out to be a bad fit too. The cam cover thankfully seems not to be leaking - I checked around it and it seems bone dry.

Any advice gratefully received.

 

[koalar]

Yes there's a metal baffle in the cam cover, it just there to stop oil splashing directly up the pipe

The normal blowby gasses are sucked in either above or below the throttle plate depending on the vacuum and burnt to reduce emissions, instead.of venting into the atmosphere

No vacuum they sit there and condense out

99% of the time it's just a problem with the breather pipes or the grommet under the air box


Eventually it will oil up the MAP sensor and cause running issues


The original genuine FCA are over £30 from the likes of shop4parts I don't know of a reliable 3rd party make

 

[irc]

Did you order by part number?
I think the Active Eco is 71747811, but i was supplied with a 46536776, which looked similar but didn't line up like yours. Some web sites are just wrong on some parts.
I find its worth checking on EPER for anything slightly unusual.

 

[eddyweird]

Our (2010 1.2 Dynamic Eco) Panda has an oil leak which shows up as a burnt oil smell whenever a drip lands on the exhaust. Both the Y-shaped hose from the cam cover breather to the air box and the sealing ring between the airbox and throttle body had clearly been leaking oil. (The hose was split at the engine end, the ring was loose fitting, maybe swollen and damaged by oil).

Very easy to find replacement parts except both the parts I ordered turn out to be a really bad fit. So I'd really value some advice on how to identify better ones. The hose, for example, clearly looks like the proper part but the size is just wrong - the middle part of the s-shape is about 25mm too long so the two ends don't line up with the hose barbs and the bore size at the engine end is much too big. Being silicone it's squishy enough to just about clamp down on the hose barb but I doubt it'll seal properly. I can't tell if it's actually meant for a different engine or if it's just a really badly made copy.

The other question that's bothering me is why there's quite so much oil in the hose at all. I'd expect some oil mist coming out of the breather but this seems excessive. Is there some kind of baffle or series of chambers inside the cam cover that's meant to trap oil mist before gases leaves the breather? (There is in other engines like the Mazda BP I'm more familiar with.) I could take the cam cover off to check for myself but now I'm paranoid the cam cover gasket I bought will turn out to be a bad fit too. The cam cover thankfully seems not to be leaking - I checked around it and it seems bone dry.

Any advice gratefully received.

View attachment 453888

Like yourself I was shocked how much oil collects in the breather pipe and at the airbox grommet, I kept checking the engine oil level thinking it was overfilled. Now reading posts on this forum it would appear it is a characteristic of the this engine.
I'm sure I read a post that a member cleans the hoses and MAP sensor as part of his/her annual service?

 

[portland_bill]

The new pipe you have is for the early engines, with the square oil cap. There seems to be several aftermarket suppliers for these.
The later engines, like yours, and mine, seem to not be catered for, or perhaps the aftermarket manufacurers have not noticed the change of spec. Shop4parts seems to be the most likely source.

 

[Martin Y]

Did you order by part number?
I think the Active Eco is 71747811, but i was supplied with a 46536776, which looked similar but didn't line up like yours. Some web sites are just wrong on some parts.
I find its worth checking on EPER for anything slightly unusual.

I did find that 71747811 part number on ePER but then struggled to find anyone selling it.

On Amazon I found this supplier of part 46536776 https://www.amazon.co.uk/gp/product/B0C9T5XY5P which looks like exactly the right part, but isn't. Incidentally the pic shows a relief notch cut out of the end which goes onto the airbox, but the supplied part doesn't have that.

I'll try the suggestion of shop4parts to try to get the right hose, and I'll try to get a better fitting version of the gasket that seals the airbox to the throttle too (46528828) as the one I got is reluctant to stay in place. Annoyingly I can't now remember where I got the poorly fitting version from.

 

[eddyweird]

Apologies for jumping in here MartinY, open question to all the knowledgeable folk.
Whats with airbox to throttle body rubber seal?
It was never a good seal and I can understand it's before the metered air so doesn't need to be, so why does it need replacing?
I can only think that it starts to behave like ramair induction kit?

 

[koalar]

Apologies for jumping in here MartinY, open question to all the knowledgeable folk.
Whats with airbox to throttle body rubber seal?
It was never a good seal and I can understand it's before the metered air so doesn't need to be, so why does it need replacing?
I can only think that it starts to behave like ramair induction kit?

The crankcase gas recirculation relies on vacuum to suck the glass into the cylinders

Without vacuum the gasses will stagnant in the pipes and condense back into oil and drip into the inlet manifold and eventually contaminate the MAP sensor


Think sucking up liquid through a straw with a hole in the side

A leak between the air box and throttle body has zero effect on the fuel mixture, it's the oil dripping in the inlet manifold that eventually effects performance

Does depend on driving style lots of low revs, short journeys and so on will cause the MAP to get contaminated quicker, long motorway drives will clear it, but if the system is 100% there still isn't a problem regardless of driving style,

 

[eddyweird]

I hate yes or no answers!

Thanks Koalar thats cleared that.

 

[Martin Y]

To be honest, the reason I wanted to replace the rubber gasket was because it was weeping oil. For as long as I've had the car, the throttle body and manifold below it have been slick with oil that's slowly leaked from there and I guess it must all have been accumulated oil vapour that settled in the airbox and ran down. The original gasket was a very loose fit and I suspect it degraded and got swollen over time because of the oil that was always coating it.

Oddly, having cleaned it all up and replaced the split Y-shaped hose, it doesn't seem to be accumulating oil there now. I can't quite figure it out, but perhaps the split in the hose was letting more air in there and carrying the oily blowby gases up into the airbox faster, before the oil mist could settle out. Or it might be that the little breather pinhole into the manifold was blocked (the one which the other branch of the hose goes to) so all the oil mist had to go up to the airbox and through the throttle instead). I couldn't tell if that pinhole was clogged or not - it had oil filling it, but a blast of air from a can of air duster cleared it out. The liquid oil might just have settled there but maybe it was blocked with sludge,

 

[DaveMcT]

My M-Jet had a cracked breather hose from the cam cover. The rubber was hard (as expected) but there's no relative movement from the cam cover stub to oil separator. The crack looked like nothing but made a right old mess down the back of the engine. I was not able to find an OEM part but a pattern fitted well enough.

 

[linelect]

Hi everyone, found suitable aftemarlet hose for my Panda 1.2 2009: ORIGINAL IMPERIUM 19658
Fit perfectly and looks the same as from factory.
This one has a relief notch cut out of the end which goes into the airbox.

 

[DaveMcT]

Hoses like the one pictured can be shortened. Use a piece of suitable diameter metal tube to join the cut. It might need hose clips to finish the job. Obviously, if you have to buy a length of tube, the cost won't be worthwhile but offcuts of plumbing are usually easy to find.

 

[The Panda Nut]

I think a catch can is worth the expense. The amount of water it collects is suprising. I have 2 fitted and had one on our 169 before it was sold last year. I find the amount of oil collected varies from one car to another and by quite a lot. Fitting seems to put a stop to fouled map sensors and reduced throttle body fouling by 95%. Search catch can and you should find my post on fitting. Preventing water vapour building up in the crank case has the advantage of eliminating may (except in the catch can)