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Can someone help? MAP/MAF sensors

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I've read people talk about the MAP sensor and MAF sensors on the E60. I'm quite ignorant on these topics, some google searching is helping me understand them a little bit..

 

Do you change these parts often or clean them? Had my car 4 years and haven't done anything like that, so I'm thinking is there any va-va-voom I'm missing out on? Even if not, if it means my car is healthier then I'm happy to do it.

 

Is it something I can do myself? I'm not an expert but consider myself quite handy with a spanner or 2.

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The boost sensor (MAP) I would remove and clean it. MAF you could replace but it depends on the cars mileage. It's a slippery slope when you start replacing components on life rather than when they complain because it can be difficult to draw the line on where to stop. Personally if you wanted to, I would fit a new genuine MAF and top o2 sensor. Boost sensor you could do if you wanted but they are less likely to fail. Modern ECUs know so well about what's going on they will usually complain when they start to act up, but not always. 

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4 minutes ago, Mashed Potatoes said:

The boost sensor (MAP) I would remove and clean it. MAF you could replace but it depends on the cars mileage. It's a slippery slope when you start replacing components on life rather than when they complain because it can be difficult to draw the line on where to stop.  

 

Thanks - my car is sitting under 134k right now.. What would you use to clean it? I get what you mean about unnecessarily replacing things, I'm just not sure if it is complaining and I'm just not realising.

 

What's a top O2 sensor?

 

 

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On that basis I would look to replace the MAF and the o2 sensor in the exhaust. Clean the manifold and boost sensor with a view to maybe replacing it price dependant. 

 

The o2 sensor will be the lambda sensor in the top of the exhaust closest to the turbo. Usually they have 4 or 5 wires going into them and they're physically bigger than the DPF temp sensors. The MAF, MAP and o2 sensor in the exhaust (excluding the fuel system) have the biggest bearing on engine performance. It needs to know how much air is going in and at what pressure to know how much fuel to inject to maintain the correct air fuel ratio fed back to the ECU from the lambda sensor in the exhaust. 

 

MAF sensors are so sensitive that for example if you do a service on a new Mercedes and don't reset the air filter in the service menu on the diagnostics, the engine management warning light will come on because of high flow through the MAF. You have to tell it it's had a new air filter to allow it to 'calibrate' itself to the new filter because the air flow reading will be slightly higher.

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Thanks, that's very helpful! Looking at your description I may be a bit lost doing this myself, I'll have a look in my Haynes when I get home to see if it's in there. If not, I think I may need to find someone to do this for me? Or is it easy enough to do

 

Sorry for all the Qs -

 

Regarding O2/Lambda sensor, is it this? Part no 13627796778

https://www.onlinecarparts.co.uk/bosch-663846.html

Is a rough price of £90 accurate?

 

MAF sensor I saw for roughly £100 - is that how much I should be looking at?

Is it no.1 here? http://www.realoem.com/bmw/enUS/showparts?id=NX52-EUR-05_2006_E60N_BMW_525d&diagId=13_1151#13627788744

 

 

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The o2 sensor you might be able to do in place without removing the exhaust or anything but I can't remember from memory. Personally for prices I'd ring Euro Car Parts up, give them your registration and tell them what you want. You'll have far less issues that way and it's easy to take parts back if necessary too. That £90 seems cheap, the o2 sensor is usually around £150+VAT and a MAF doesn't normally come in at under £200. It might be worth speaking to them though, see what they can do for you. 

 

I must stress - only go with genuine Bosch parts. It's not worth the headache that cheaper parts cause.

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Sounds good.

 

I had a gander at ECP's website - I do wonder that whenever they have a promotion going on, the prices seem to shoot up a little lol. But anyways:

- MAF sensor BOSCH is around £235, £150 after discount.

- Lambda Sensor is £125ish after discount

 

So roughly £275 for both.

 

It says that the ECU will need reconfiguration after the MAS Sensor replacement, is this true?

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The BMW ECU will eventually self learn, but it's best to tell the car it has had the MAF and o2 sensors replaced. A garage will do this for you no problem if you don't have any BMW diagnostic equipment yourself. 

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1 hour ago, Mashed Potatoes said:

The BMW ECU will eventually self learn, but it's best to tell the car it has had the MAF and o2 sensors replaced. A garage will do this for you no problem if you don't have any BMW diagnostic equipment yourself. 

 

do you need to do that with the E6x?  I know the newer F and G models have to be told everything

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22 minutes ago, Dotcom1970 said:

 

do you need to do that with the E6x?  I know the newer F and G models have to be told everything

 

Yes, it's not a must do but every diagnostic tool I've used has given the option to reset their parameters so I would always do it just to speed up the learning.

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I managed to brick my iCarsoft 910-II yesterday, so awaiting a reply from technical services, unless anybody had an older update file...

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MAF sensor you can replace yourself easily. MAP sensor is screwed into your plastic intake. It's a single bolt that holds down a bracket with a wire into it, on top of the engine, right side. It can be cleaned with electronics cleaner, isopropanol. Soak it for 5 min and put it back. 

Unplugging sensors will give you an error code, but it won't show anything in your display.

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18 hours ago, TheNorwegian said:

MAF sensor you can replace yourself easily. MAP sensor is screwed into your plastic intake. It's a single bolt that holds down a bracket with a wire into it, on top of the engine, right side. It can be cleaned with electronics cleaner, isopropanol. Soak it for 5 min and put it back. 

Unplugging sensors will give you an error code, but it won't show anything in your display.

 

Cheers for the reply.

 

I don't have access to diagnostic equipment, is there another way reset the error code?

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I don't think so, but since you won't see it anyway, it shouldn't matter for you. The car doesn't care it's there either. You probably have a bunch stored. I cleaned mine yesterday, and I didn't need to unplug it. 

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