Leaderboard

Hi the trail starts thus, Air intake to filter box then in to MAF which registers the air temp coming in, the filter element is made of a cotton/paper mix with a porous surface of microscopic holes, thousands of them, when the material is past its best the engine vacuum will be greater than normal to reach its optimum flow rate this in turn deforms the pores in the filter material thus allowing larger parts of foreign matter into the air intake which then goes through the MAF sticking to the diode surface which as I said is constantly heating and cooling the bigger particles of matter will heat up and burn the diode surface which is covered in a heat proof lacquer which perforates and gives false readings, the last line of defence is the MAP sensor which picks up the extra air from the leak and reports that the MAF sensor readings are corrupted and the ECU needs to up rate the duration of the duty cycle of injection [more diesel] to cope withe the extra air it has logged, allied to the lost boost pressure this creates an over fuel situation which is what clogs the DPF, BTW if an air leak exists or boost pressure is lost the ECU suspends the regeneration process that naturally occurs as a safety protocol until the sensors have sorted out the communication problem this is to stop emissions from going up further, the situation you describe with petrol engines only existed with carburettor fuelled engines as the carb fuel flow rate was not monitored by the ECU where as the advent of fuel injection gave the ECU the facility to raise or lower injection cycles, most petrol engines from the early nineties with a blocked air filter would show a code for airflow threshold lower than expected and an EML, that came on when the ECU had exhausted its paramiters for cutting injection amounts, the MAF is upstream this designation is made from the calculation that the airflow comes into the box is filtered then passed to the MAF which creates circular used air into the turbine this stops air friction from warming the air as it travels in whilst creating negative vacuum to pull the crankcase gas through the system into the turbo intake, where boost pressure is lost the crank gasses do not mix efficiently with the intake air and start to atomise properly which also clogs the intercooler and DPF. Steve

Hi your problem is where the pipe goes in to the turbo the rubber seal is compromised thats why its letting all the CR@P from the PCV get blown out before it goes into the engine to be burnt, this also works in reverse as it allows air in which the MAF won't have registered and you will also be loosing boost pressure, you also completely defeated the object of the whole exercise as leaving the ducting off creates the same problem as it will draw extra air from all over the surface of the air filter rather than just through the ducting which is the prime source, if I were you I would add a DPF cleaner to the fuel and give it a forced regeneration before you total the DPF and the CAT, I change my air filters about six times a year or every 9k for what they cost its a no brainer and I wouldn't mind betting thats whats killed the MAF, they are very sensitive inside to dirt as if the filter has stopped working properly it allows tiny particles of dirt into the intake system which sticks to the diode inside the MAF, the diode goes into super heat when you turn the engine off this process cleans the diode of any oily film but if you have larger contaminants it will heat up and burn holes in the protective coating on the diode which causes it to read incorrectly, whilst running the diode constantly heats and then reports the cooling time to the ECU which gauges the ambient temperature of the in comming air and adjusts the injection ratios according to the latest information from the MAFF,MAP correlation. Steve.