Possible Camshaft Sensor Problem

[Bringit96]

So I've got the usual symptoms; rough idling from very cold starts with one cylinder not kicking in straight away and sometimes struggling to start with a warm engine.

Now the problem has progressed and the car dropped a cylinder whilst idling on the last leg of a normal motorway drive. When I put the car in neutral or changed gear to lower revs it would drop a cylinder.

After about 10/20 seconds it would come back and run fine. It was a 50/50 chance the cylinder wouldn't run when I stopped and idled.


Managed to get the car home and parked but the next time I need to start will be to take it for its MOT. I'd rather change the sensor than be billed for 2 hours work.

The spark plugs need changing anyway so I'll see how it runs after they're changed but I doubt they're the problem.


Would this be a camshaft sensor issue or crankshaft sensor issue?

 

[mrscalex]

Could be something else again. Best to stick a code reader on.

The most bizarre one I've ever had was a corroded DME pin which wasn't sending the firing signal to cylinder 4.

 

[Faheem]

It could be a camshaft sensor - these are prone to failure on the M44 engine.

Having replaced the sensor at least 4 times now (on 2 different cars!) I can say that it's best you go with a BMW sensor if you do replace it. They are around £100 from Sopers after discount.

The sensor is relatively easy to replace. A 5mm allen bolt holds it onto the timing case cover, you then have to remove the three bolts that hold the upper intake manifold on to get access to the sensor plug which sits underneath some vacuum hoses under the upper intake manifold. Take your time when removing the sensor from the clip as these become brittle and can break easily.

But as Rob has said, it's definitely worth putting a code reader and scanning it for faults before spending that kind of money. Think I was seeing a P0340.

I had a separate issue with my zed for a very long time where it would run rough, always in the cold - whenever the temperature would drop, the car would take ages to start almost sounding as if the timing had gone and then start on 2/3 cylinders. I had no fault codes. For me changing the oil a few times over a 3 month period with 0w-40 solved the issue. Tony actually recommended giving that a try and he was spot on. Think it may have been sticky valves.

 

[colb]

Deffo put a code reader on it, should see the misfires reported and indicate which cylinder is doing it. Also a code for bad camshaft sensor if your lucky. Worth changing the plugs, what about moving the plug coils about to see if the misfire moves with a bad coil, code reader will tell you that by indicating which cylinder is misfiring. Ifyou have to replace sensors use OEM parts not cheap ebay items, been there done that etc.

 

[Bringit96]

Thanks for the feedback, next question is which OBD2 reader? There are so many I've read up on the forum and found the ELM Bluetooth scanner.

Wondered if something like this would work better?

https://www.amazon.co.uk/Universal-...AV0AKFRCEK3&psc=1&refRID=FXJTVYK41KFWNB2RQRAD


Seeing as I have to get the adapter anyway is it worth getting both and having a backup?

Worth changing the plugs, what about moving the plug coils about to see if the misfire moves with a bad coil, code reader will tell you that by indicating which cylinder is misfiring.

Ah yes....I know I have a plug that has electrical tape wrapped around it. I'll move that up the to-do list

 

[colb]

Quite a few members in Lincolnshire will have code readers and may help you out, one may be along in a min.

 

[mrscalex]

I might be up in Lincs. Thu/Fri of this week or next week. If you are not too far out of the way and if I have time I'd be happy to swing by. But it might be whistle stop to read the codes rather than start helping to try and fix it.

The C110+ is a popular reader and not expensive. I am not recommending this seller but it shows the unit and extra cable you need for a Z3

https://www.amazon.co.uk/Autool-Creator-Automotive-Diagnostic-Scanners/dp/B074Z73ZBV

And I've got one of these cheapies (well not that much less than the C110+) I use for my daughter's Peugeut/Citroen which works well and would probably work on a Z3 too with the above adapter.

https://www.amazon.co.uk/HappyCow-Computer-Diagnostic-Automotive-Scanners/dp/B078X96QZC

However tread carefully as if you have an early pre 98 car (I think) there is an issue that blocks reading certain codes and i don't know my way round it as my cars are all facelift.

 

[mrscalex]

Btw the link you posted may well be the same unit inside as the one I posted. And it may well be fine anyway. But when dealing with unknown commodities like this I always run the Amazon URL through Fakespot.

https://www.fakespot.com/product/ob...anner-for-all-obd-ii-protocol-cars-since-2000

To be honest if you can afford the extra £10 I'd personally go with the C110+. I use laptop based software which has many more features but is more complicated to install and use and probably best avoided unless you are comfortable with fighting PCs.

 

[the Nefyn cat]

I'll second the C110+, had a generic reader before and this one's a whole lot better, and does more stuff (air-bag light, for starters).

 

[Bringit96]

That reminds me, I'm more London based now so I'll change that on my profile. Thanks for the input, my adapter has arrived and the C110+ arrives tomorrow!

 

[the Nefyn cat]

That reminds me, I'm more London based now so I'll change that on my profile. Thanks for the input, my adapter has arrived and the C110+ arrives tomorrow!

Don't be surprised if it doesn't want to update, had mine quite a time now and never yet managed it. Not sure what exactly it updates, works perfectly well without.

 

[Bringit96]

So I plugged the reader in, pressed a few buttons and got this:








I changed the spark plugs while I was there and cylinder #2 came out with oil on the coil plug and the spark plug. I've kept the old spark plugs to double check how they've worn

 

[BMBabe]

@Bringit96 You are closer to Zedshed HQ Now @Lee

 

[colb]

Oil on plug points to failed rocker cover gasket fueling problems may also be down to leaking rocker cover gasket letting in unmetered air had this on the 2.2 earlier in the year that had cracks in the plastic rocker cover replacement with new gasket solved that

 

[colb]

Oil in and on plug indicates failed rocker /cam cover gasket leaking also fuel adaptions indicates its running rich as its probably sucking air in through the failed gasket its seeing unmetered air in the exhaust telling it is running lean check the plastic rocker cover for cracks as well had this on a 2.2 not long ago
DOUBLE POST

 

[ktnez99]

So I plugged the reader in, pressed a few buttons and got this:

View attachment 120653

View attachment 120657

View attachment 120655


I changed the spark plugs while I was there and cylinder #2 came out with oil on the coil plug and the spark plug. I've kept the old spark plugs to double check how they've worn

Is there any sort of instruction manual that came with the cider and will help you read the codes? @Bringit96

 

[colb]

Interputating the codes is the key over adaption and misfires point to vacuum leak oil leak points to failed rocker gasket and pos source of air leak

 

[mrscalex]

71 is the ABS pump or most likely the module attached to it. You must be getting the ABS light? I've not seen 81 before but it's saying relay so would be worth tracking down the relay associated with the ABS and checking that. Unless it's an internal relay in the module itself. Not sure.

 

[Bringit96]

Is there any sort of instruction manual that came with the cider and will help you read the codes? @Bringit96

Nope, I've had a look online but can't find anything conclusive.

This is the only thing I've found but still doesn't clearly say what errors are: http://www.endtuning.com/bmwcodes.html I'll have a look and see what I can make from it.

71 is the ABS pump or most likely the module attached to it. You must be getting the ABS light? I've not seen 81 before but it's saying relay so would be worth tracking down the relay associated with the ABS and checking that. Unless it's an internal relay in the module itself. Not sure.

It came on once when I went over a bumpy section of road at some speed...It went off on its own short after

 

[Bringit96]

C110+ Code reader : End Tuning BMW Codes

3E Misfiring : 62 Misfiring multiple cyl.
33 Mis Cyl 2 : 51 Mis Cyl 2
4B Misfiring with Cyl cutout : 75 Misfiring multiple cyl
41 Mis Cyl 3 with cutout : 65 Mis cyl 2 with cut out
34 Mis Cyl 3, relevant to exhaust gas : 52 mis Cyl 3
1B Addative mixture : 27 Addative mixture
32 Mis Cyl 1 `: 50 Mis Cyl 1
3F Mis Cyl 1 with cut out : 63 Mis Cyl 1 with cut out

Nothing conclusive....?