Cleaning MAF

[dragon]

In Parrot's posting on cleaning, it says use Isopropyl alcohol, where can I get it locally. I been to Halfords, they said go to chemists like Boots. I been to motor factor they said use Engine degreaser. On closer look the contents are HydroCarbon distillate. Can I use lighter fuel?

 

[rpe2]

http://cgi.ebay.co.uk/ISOPROPYL-ALC...39:1|66:2|65:12|240:1318&_trksid=p3286.c0.m14

Or Maplin's or such like.

Richard

 

[dragon]

Thanks Richard.

 

[television]

Cleaning the MAF on cars hardly ever works,, 2 reasons on petrol MAF's there are 2 types, on the early hot wire type, the wire erodes away knocking it out of spec, the later sensor types also go out of spec, you must remember that these things live in a hostile environment, all of the air entering the engine goes via the MAF,,this include moisture and micro grit, the bombarding of the sensor over the miles does alter the characteristics. In the case of a diesel the air flow is much faster than for petrol and wear quicker,, diesel being a slightly more oily fuel than petrol can leave deposits on the MAF that can wash off,,,I would use lighter fuel as this is refined petrol and it leaves no deposits

 

[Jay Gee]

Television,I seem to remember having read before that airflow is higher in a diesel-but I can't seem to get my head round it as I thought diesels run at lower revs generally.Could you please explain this to me? Many thanks.

 

[television]

They run at a much higher compression than a petrol,, so it needs more air to compress

 

[dragon]

Cleaning the MAF on cars hardly ever works,, 2 reasons on petrol MAF's there are 2 types, on the early hot wire type, the wire erodes away knocking it out of spec, the later sensor types also go out of spec, you must remember that these things live in a hostile environment, all of the air entering the engine goes via the MAF,,this include moisture and micro grit, the bombarding of the sensor over the miles does alter the characteristics. In the case of a diesel the air flow is much faster than for petrol and wear quicker,, diesel being a slightly more oily fuel than petrol can leave deposits on the MAF that can wash off,,,I would use lighter fuel as this is refined petrol and it leaves no deposits

Hi Malclom,

Hope you enjoyed your socialising today.

If cleaning is not recommended when is the best time to start replacing it? Currently it hesitates on 3/4 roundabout. Not sure it MAF or too low gear (3rd) of 6 manual gears 2001 2litre petrol kompressor slk or something else. There is yellow goo around the joint which I cleaned off.

My 97 C180 is older 12 years and is still OK because I looked after it from new, I looked at it again today, it clean and no yellow goo.

 

[television]

The yellow goo will be an oil waste from the compressor, just wash it away,, the lower rev band is affected first when they go down and cause hesitation say at 2k and this can be seen by measuring the voltage on one of the pins,,but you need a break out box to do this so thats out of the question

 

[dragon]

The yellow goo will be an oil waste from the compressor, just wash it away,, the lower rev band is affected first when they go down and cause hesitation say at 2k and this can be seen by measuring the voltage on one of the pins,,but you need a break out box to do this so thats out of the question

There are at least 4 pins and inside the MAF I can see a pink diode.

What a breakout box? I got an avometer.

 

[television]

There are at least 4 pins and inside the MAF I can see a pink diode.

What a breakout box? I got an avometer.

A break out box is a socket and a plug combined with access points to all of the pins so that voltages can be measured and links can be removed to measure current with the item under test in situ

 

[Jay Gee]

Television wrote ' They run at a much higher compression than a petrol,, so it needs more air to compress'
_
_Thank you for that.Kicking myself for not having thought of that,but in truth,I probably never would have.

 

[colechelle]

good answer!!!!

 

[television]

If this subject is taken one step further,, this would explain why a blown diesel is so much better the a normal aspirated.

The 124 300D takes around 18 seconds to get to 60 and the 300TD that never came to the UK does it in under 10 sec

 

[rpe2]

Oh do tell...

If this subject is taken one step further,, this would explain why a blown diesel is so much better the a normal aspirated.

The 124 300D takes around 18 seconds to get to 60 and the 300TD that never came to the UK does it in under 10 sec

 

[television]

Oh do tell...

Diesels are not my line and I know little about them other than you must not fill them with petrol:-|

 

[stumo]

They run at a much higher compression than a petrol,, so it needs more air to compress

But higher comperssion doesn't mean it needs/has more air, it just means that it compresses the same air more.

I think the MAF failures are more to do with the harsh environment. Eg when you shut down your engine there is some back-flow of nasty gasses/particles back out of the engine on the inlet side.

 

[television]

On a petrol engine the air fuel is atomized long before it gets into the cylinders, a diesel engine just takes in air, compresses it and then injects the fuel into that cylinder.

The air on a petrol engine is proportional to the throttle opening, this is not the case with a diesel as the max air is drawn in all of the time, and this is why the air flow is greater.

Petrol engines have a compression ratio of up to 8;1 to 12;1
and diesel from 14;1 to 25;1

If you can explain it better then please do

 

[stumo]

The air on a petrol engine is proportional to the throttle opening, this is not the case with a diesel as the max air is drawn in all of the time, and this is why the air flow is greater.

Ahhh yes, that statement alone explains it perfectly. Compression ratios don't really have anything to do with it. Now I understand (all things being equal) how a diesel will have more air going through the MAF over time.

 

[television]

Ahhh yes, that statement alone explains it perfectly. Compression ratios don't really have anything to do with it. Now I understand (all things being equal) how a diesel will have more air going through the MAF over time.

Thanks its good sometimes to think about these things,,makes it easier with faults too. I am always willing to learn and enjoy these discussions any other ideas please ask or explain what ever and thank you

 

[television]

Ahhh yes, that statement alone explains it perfectly. Compression ratios don't really have anything to do with it. Now I understand (all things being equal) how a diesel will have more air going through the MAF over time.

Thanks its good sometimes to think about these things,,makes it easier with faults too. I am always willing to learn and enjoy these discussions any other ideas please ask or explain what ever and thank you