If the breather starts to get blocked it will cause excessive pressure in the crankcase. This will the cause the oil to over pressurise and leak out of the weakest area, which is normally always the turbo seals. This will then cause oil in the exhaust manifold, excessive smoke and ruin the DPF if fitted. It sounds like your turbo seals are going to be honest.

 

Hi thanks for you reply I’m struggling to understand how excessive crank case pressure can effect oil delivery pressure oil pressure is supplied by the oil pump ........ the turbo’s don’t have oil seals that on the oil freed side it does have bushes that can ware out ! The rubber seals on a turbo are on the air intake side and boost side the crank case pressure as far as I can see is piped in the the turbo pipe work after the turbo’s So I still don’t understand how crank case pressure can effect the turbo’s?

 

The crank case breather vents into the low pressure intake before the turbo so the engines inhales and consumes the fumes. When the breather is blocked the crank over pressures and these glasses cant get out, with these extra gases and the crank/piston movement this causes the oil system to over pressurise. This causes damage to the turbo oil seals and causes oil to let buy and eventually totally failure.
You car was originally fitted with a loo roll type oil breather filter which were notorious for blocking up. The later cars 2007 onwards were fitted with a cyclone breather which was less prone to fouling up.

 

Hi when you say the crank case blockage causing the oil system to be pressurised what do you mean ? Oil pressure or crank case pressure ? How does crank case pressure effect turbo seals ?? The turbo has a oil pressure feed and Low pressure return to the sump I cannot see how crank pressure is effecting oil pressure ! And can you explain exactly what seals you mean when you refer to turbo oil seals ?

 

The oil sits in the bottom of the crankcase at the same pressure as the crankcase itself. If the crankcase pressure goes up so does the pressure that oil is under. Once that exceeds the pressure a seal can hold the seal will let by and the weakest seals on the engine are in the turbo.

 

I need to understand how the crank case pressure relates to the seal in the turbo ? And exactly what seal your referring to as the only seal I can think of is an o ring type that seals the turbo cases the turbine shaft Rotates in bushes when they ware out the turbo passes oil and there in excessive play in the shaft I understand completely how crank case pressure works I just don’t understand how it can effect oil feed pressure and as the oil in a turbo is oil feed pressure and when a turbo fails resulting in excessive play in the turbine shaft then allowing the oil feed to the turbo to pass in the inter cooler and then in to the intake resulting in high oil consumption and burning oil I understand that if crank case pressure is to high and the breather becomes overwhelmed that it can dump oil in to the air intake system filling the inter cooler With oil in a similar way my turbo’s have very little free play so I don’t believe they have failed but my inter cooler has excessive amounts of oil in it so I believe the breather is dumping oil in to the turbo pipe work what is confusing me is that this problem is intermittent I have already changed the breather to the later vortex type but the problem still persists

 

The turbo is fed oil supplied by the oil pump the crank case pressure is relieved by recirculated blow by gasses back in to the inlet system I don’t understand how excessive crank case pressure can damage/ destroy / the turbo Or as you say blow seals in the turbo ? I work on the principle that you can’t fix what you don’t understand hence my need to understand the connection between oil pressure created from the oil pump and crank case pressure? If there are seals in the turbo that I don’t know about I’d like to be educated of what and where they are .... many thanks for your time and input

 

Go and have a search on Google it's excessive crankcase pressure causing turbo failure and is fairly common as a failure point. Sometimes the crankcase over pressures because of piston ring blow by this can cause the same fault. On these engines though it caused by the breather clogging up. The oil leak can come from either the compressor or the turbine side of the turbo.

 

Yes it’s certainly true there are lots of people stating that excessive crank pressure causes turbo failure but my question remains unanswered as how ??? How can excessive crank case pressure effect oil pressure? My second unanswered question was whats specific oil Seals fail due to excessive crank pressure my questions are specific........ I’m pretty sure that my breather is dumping oil in to my air intake pipes and filling the inter cooler what is strange is that it’s seems to be an intermittent fault I have changed the vortex breather for a new one so very strange..... thanks for your input but still none the wiser

 

Not sure about that. This would be true if the oil pump were a centrifugal pump, however, the oil pump is a positive displacement pump (gear pump) and its outlet pressure is a function of the discharge back pressure, not the inlet pressure. (crankcase pressure) OP is correct in better understanding the oil circulation system and how it might be affecting his/her problem.