Cleaning Mass Flow Sensor (2.0HDI)

[andy-womble]

2.0 HDI Engine,

Whilst having a nose under the bonnet the other day I had the air filter out and removed the elbow containing the mass flow sensor.
Noticed a few specks of what looked like oily globs on it, which had presumably been drawn from the crankcase breather.

I know theses sensors are extremely delicate and should not be touched for risk of damage but wondered if anyone on the forum had actually cleaned one using carburretor cleaner, brake cleaner or similar and with what results???

Need to know before I launch in with my delicate little donnies and do some lasting damage!!!!

[3rensho]

What is the function of the mass flow sensor?? Never heard of one.

[andy-womble]

Hello 3rensho
The mass flow sensor is located in the ducting between the air filter and the inlet manifold.
Its function is to monitor the amount of air being sucked into the engine for the purposes of combustion (posh name "Mass Flow"). Having monitored the amount of air the engine is receiving it sends a signal to the ECU (Electronic Control Unit or engine management computer). From this information, the computer then decides how much fuel needs to be sent to the injectors to achieve an efficient "burn" or ignition cycle. This is a laymans description and I am not yet familiar with the technical intricacies of how this is acheived.
All that I know is that if the sensor, which is in full flow of an airstream, should happen to get contaminated with oil or other inclusions then it will affect the running of the engine, fuel efficiency and possible throwing up of fault codes and illumination of the engine management light.

Hope I have enlightened you, you now know as much as I do on the subject !!!

Since my motor has been throwing up intermittant faults, the engine management light keeps illuminating and in an effort to familiarise myself with the vehicle, I am trying to rule a few things out. Really, as I have stated in other threads, I need a code reader but am not ready to buy one yet until I know it will work 100% with my vehicle.

[3rensho]

Thanks for the explanation Andy. These new cars are amazing in their complexity to be sure. I liked the days when it was just set the points and timing, gap the plugs and an occasional carb rebuild. Gas was $0.25 a gallon and you got your windows washed, tires and oil checked.

Tom

[andy-womble]

Thanks for the explanation Andy. These new cars are amazing in their complexity to be sure. I liked the days when it was just set the points and timing, gap the plugs and an occasional carb rebuild. Gas was $0.25 a gallon and you got your windows washed, tires and oil checked.

Tom

Me too, Tom.
Back in the late 1980's, In addition to my full time job I used to do a bit of part-time lecturing in motor vehicle technology to aspiring apprentice motor mechanics at the local technical college. The new technologies were coming in at that point and were a nightmare to stay in touch with then.

I spent some time out of touch with the motor trade but in my last job I worked for a commercial vehicle dealership in an administrative role. The advent of electronically controlled diesel engines had begun by then and the new technology phased me completely and blew me out of the water.

Diesel engines controlled by electronics and computers, nah your having a larf guv'nor!!!!.... I remember when I was an apprentice...

Unfortunately they weren't having a laugh and it looks like the new concepts are here to stay.

[scarab]

Need to know before I launch in with my delicate little donnies and do some lasting damage!!!!

You could try electrical switch cleaner solvent from a spray can, that May do the trick it's used on electronic thingamabobs so might be a good bet..?

[pk7478]

andy-womble. Do not use solvents. Use only alcohol.

[andy-womble]

andy-womble. Do not use solvents. Use only alcohol.

Thanks for that pk7478, what alcohol would you suggest???
eg isopropyl alcohol or whatever????

Appreciate your advice on this please.

[raf35y]

Re which alcohol to use,
I've been using gin for quite a while now (with a bit of tonic) works every time, I run a bit rough the following morning though

sorry for being of no help what so ever.[/i]

[pk7478]

andy-womble. Do not use solvents. Use only alcohol.

Thanks for that pk7478, what alcohol would you suggest???
eg isopropyl alcohol or whatever????

Appreciate your advice on this please.

No, of course.
Use C2H5OH. It's cheaper and safely