3.0Si (N52) suspected MAF - rough idle/slow pick up (not loving Carly...)

jamie_z4 · Post by **jamie_z4** » Thu Jan 11, 2018 1:37 pm

Maf is very rarely the case with these cars.

The amount of forum diagnosing over the years I've seen 'its the MAF' mate is frightening. The maf rarely fails, the most likely suspect is the cam sensor, eccentric shaft sensor or an air leak. All pretty common on the n52.

Chris1981 · Post by **Chris1981** » Thu Jan 11, 2018 3:12 pm

Can the eccentric camshaft sensor go without there being an oil leak into it? I simply assumed that no oil leak or poor performance meant it was ok!?

Good shout though Jamie, camshaft sensor could well be the issue Newbers is facing if he has a slow pick up too... the Vanos system won't be functioning correctly so power will be affected, this was the case in my M3 when the inlet cam sensor went! But gave me n error code so was easy to pinpoint!

jamie_z4 · Post by **jamie_z4** » Thu Jan 11, 2018 3:19 pm

Chris1981 wrote: ↑Thu Jan 11, 2018 3:12 pmCan the eccentric camshaft sensor go without there being an oil leak into it? I simply assumed that no oil leak or poor performance meant it was ok!?

Good shout though Jamie, camshaft sensor could well be the issue Newbers is facing if he has a slow pick up too... the Vanos system won't be functioning correctly so power will be affected, this was the case in my M3 when the inlet cam sensor went! But gave me n error code so was easy to pinpoint!

the cam sensors are common on most BM engines to be honest mate, very subject to rapid heating and cooling being in the block

the Eccentric shaft sensor the seal usually fails from the cam cover which means a dead sensor, but as you say, if its dry, its unlikely its failed.

Newbers · Post by **Newbers** » Thu Jan 11, 2018 5:10 pm

I must confess I didn't know I even had an eccentric camshaft sensor.

At the moment the car is stuck in the garden blocked in by a skip and about 10 tonnes of hardcore, hopefully a few of these jobs will get sorted this weekend....

Tomsdad · Post by **Tomsdad** » Sun Jan 14, 2018 9:07 am

For what it's worth I have the same car same engine and it had the same symposium and same errors
Check the long thread under my name.
Turned out to be the vanos solenoids. A ZERO COST AND VERY QUICK FIX. Just remove and clean them.
Always do the cheap fixes first before buying parts.

Newbers · Post by **Newbers** » Tue Jan 16, 2018 1:03 am

I got 10 mins to muck about with Carly over the weekend. I can't say I'm overly impressed with it.

I've got the following codes which when cleared come back:

- Fault: Air mass meter
- Code: 002D0F
- Fault: :Mixture Control 2: mixture too lean
- Code: 002A2F
- Fault: :Mixture Control: mixture too lean
- Code: 002A2E
- Fault: Air-mass system
- Code: 002D06

Do they mean anything to anyone?

I have to say the top of my engine sounds really rattly (a friend thought this might have something to do with the injectors and mixture problems - not sure about that tho).

Regarding Carly does anyone know whether 'Parameters' would help for getting insight in to the fuel trims?

Chris1981 · Post by **Chris1981** » Tue Jan 16, 2018 11:40 am

I've currently got the 2 lean codes you're getting... however I've just installed an induction kit so hoping it's something to do with that! I also have a '002AAC Variable intake manifold actuator 2' code.

If I saw the 2 MAF errors you have I'd certainly be suspecting MAF... unless it's not MAF and they are coming up as a result of the lean mixture codes!?

I too think my engine is excessively rattly and know what you mean about injectors as it does sound like it's coming from that area but I've just put this down as HVA or possibly the DISA valve i now get a code on!

Forget about parameters on the N52 engine, i've never managed to get anything working on that front!

It'd be nice if there was another member with an N52 engined Z4 nearby so you could swap MAFs to see if it clears your issue before you go spending the £300+ for a new one! I'm in based Rugby and would happily help but that may be a bit far away...

Newbers · Post by **Newbers** » Thu Jan 18, 2018 1:43 am

Last night I took the first engine cover off and cleaned everything with degreaser. In addition to the valve cover gasket it also appears the oil filler cap is leaking a little too because there was a small amount of oil on the top of the engine cover. Replacements ordered.

More importantly I ran the engine up to temperature and was very aware of a new noise. Hard to describe - think along the lines of a marble in a round, rigid plastic box. Using a wobble bar as a stethoscope I couldn't really locate the source but I was pretty certain it was on the intake side and below the manifold. This makes me think DISA - is that reasonable given noise, poor running and codes?

It looks pretty awkward to get to just to whip it out and have a look and not too many options for sourcing on-line. (£274 in UK or £250 in Lithuania....)

I had a 400 mile journey today but took the wife's car as I don't think driving is a good idea sounding like that.

I've got a mobile BMW specialist coming out next week to do the rocker cover gasket. He's got decent diagnostic kit so hopefully he can confirm the DISA and sort that out too.

Chris1981 · Post by **Chris1981** » Thu Jan 18, 2018 12:35 pm

With a decent diagnostics kit he should be able to operate the DISA valves manually and confirm whether that is the cause, the smaller valve in the lower section of the intake is a pain to remove and requires the manifold to come off so worth being sure before undertaking that job!

It has been known for DISA valves to fail on the N52 engine so is possible, I believe another forum member had issues with the small DISA valve so might be worth a search to see if you can find their thread and whether their symptoms matched yours!?

Good luck, hope you get to the bottom of it soon!

ph001 · Post by **ph001** » Thu Jan 18, 2018 1:05 pm

Could be the DISA valve for the rattle and poor running but if your diagnostics are coming up with error code for MAF, it wouldn't seem sensible to not suspect the MAF as the primary reason.

Markos_Z4 · Post by **Markos_Z4** » Sun Aug 19, 2018 1:57 am

i lost performance with a dirty MAF sensor i cleaned last month with air intake cleaner and everything is fine right now !
don't use brake cleaner !

Markos_Z4 · Post by **Markos_Z4** » Sun Aug 19, 2018 2:17 am

the problems i had
* camshaft sensor fault code ( i don't know why. . . i think with a false start it will give that code ) i think a commen problem with si engine
* Lambda probe defect ( got new one ) shakky take offs
* no power ( performance with take offs ) dirty MAF sensor ( cleaned with air intake cleaner ) no brake cleaner ! ( no fault code )

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