Engine: D52447: Engine Service Required - MAF Cleaning

[Shadeyman]

I'm in the middle of doing a service on our XC90 so I had some tools and MAF Cleaning Spray in the boot when the car lost power and the dreaded "Engine Service Required" appeared. I was on my way home from Plymouth when it happened, 4 times in total. The 4th time I decided to pull onto the services to see if it was anything obvious like a split pipe or loose connection.

Having owned quite a few diesels over the years I knew the simple things to check, fuel filter, MAP sensor, MAF sensor etc..

As the MAF sensor on our XC90 is easy to get to I removed it, shone a torch on the MAF element(small thin wire) and could see it was dirty so I grabbed the MAF cleaning spray out of the boot and gave it several good blasts. Didn't want to wait for it to slowly dry so I took it into the gents toilets and used the hand dryer.

Fitted it back on the car and it drove home 200+ miles perfectly, infact I'm sure it feels better now than when I first brought the car.

[poisondart]

Originally Posted by Shadeyman

I'm in the middle of doing a service on our XC90 so I had some tools and MAF Cleaning Spray in the boot when the car lost power and the dreaded "Engine Service Required" appeared. I was on my way home from Plymouth when it happened, 4 times in total. The 4th time I decided to pull onto the services to see if it was anything obvious like a split pipe or loose connection.

Having owned quite a few diesels over the years I knew the simple things to check, fuel filter, MAP sensor, MAF sensor etc..

As the MAF sensor on our XC90 is easy to get to I removed it, shone a torch on the MAF element(small thin wire) and could see it was dirty so I grabbed the MAF cleaning spray out of the boot and gave it several good blasts. Didn't want to wait for it to slowly dry so I took it into the gents toilets and used the hand dryer.

Fitted it back on the car and it drove home 200+ miles perfectly, infact I'm sure it feels better now than when I first brought the car.

Nice one Shadeyman!

[bobdabuilda]

did you use isopropyl alcohol spray?

[Shadeyman]

Originally Posted by bobdabuilda

did you use isopropyl alcohol spray?

I've no idea.

This is what I used.
http://www.youtube.com/watch?v=vPT8rL0noYg



I've attached a couple of PDF documents that I have for it. I haven't read them(yet), didn't really have time stuck on the services. Have a read, maybe it does contain "isopropyl alcohol". One thing I do know, its specially formulated to do the job and it definitely works, my car feels better now than when I brought it.

[Coconut]

As the MAF sensor on our XC90 is easy to get to

Any chance of a photo or description of where the MAF sensor is located, and how it is removed,
in case anyone else should have the same problem, and fancies trying this ?

Cheers,

[Shadeyman]

Originally Posted by Coconut

Any chance of a photo or description of where the MAF sensor is located, and how it is removed,
in case anyone else should have the same problem, and fancies trying this ?

Cheers,

Yes, no problem.
I'll remove it again later this morning and upload a few photo's.

[Shadeyman]

@Coconut

Here's a photo of the engine bay, a red arrow showing the position of the MAF sensor.



Here's a photo of the MAF sensor, unplug the connector the red arrow is pointing to.



The red arrows show the 2 torx screws and jubilee clip that have to be undone.



Here's a photo of the MAF sensor removed, a red arrow shows where you should direct the MAF cleaning spray. The small wire is difficult to see unless you have a torch.



Hope that helps ...

[Funky Diver]

Cool, cheers fella

[Shadeyman]

Bosch MAF sensors have a self clean cycle, If I remember correctly the sensor wire is heated for about 5 seconds every time the engine is turned off. I'm sure the wire glows red, yes it does get that hot. While the heat it produces burns 99.9% of the crap that does find its way onto the wire, the stuff doesn't always fall off the wire, some stuff clings on causing false readings and in my case the "Engine Service Required" error. Using MAF cleaning spray helps to dislodge those stubborn bits of crap and return the MAF sensor to its former glory.

EDIT.
I've just attached a PDF document to this post. Its an interesting read if you want to know a little more about MAF Sensors.

[Funky Diver]

Had a bit of a mooch about on the web, and Halfords Electrical Contact cleaner seems to get good reviews for MAF cleaning. And it's only £4 compared to the bespoke MAF cleaners out there.