Pcv valve/ crankcase ventilation

Cliveost · Post by **Cliveost** » Sat Oct 16, 2021 2:30 pm

Hi
Does anyone know of any problems with the crankcase ventilation on the 2.0 n75 engine. Mine is the twin turbo one from 2010. Is there a regular service requirement for them. I noticed a slight oil leak in the general area of the valve.

X5Sport · Post by **X5Sport** » Sat Oct 16, 2021 3:20 pm

I think you mean the N47 engine for the 2.0D? No N75 engine in BMW X-series cars. What variant do you have? 20d/23d?

There’s nothing specific that I can find around it in the routine servicing for single or twin turbo versions. It’s only mentioned for the petrol engines and not as part of a service.

Cliveost · Post by **Cliveost** » Sat Oct 16, 2021 4:19 pm

Sorry yes it’s the n47 engine. Mine is the 23d. Is there any history of problems with the crankcase ventilation system on this engine

X5Sport · Post by **X5Sport** » Sat Oct 16, 2021 4:37 pm

This might give you a clue…..and refers to the beast you may be looking at…

https://youtu.be/wt8GxM_hR6Y

Timing chain is the one to watch on this generation of the 4-cyl units. Regular oil changes are essential - even if not doing the miles.

Do a search for “N47 crankcase problems” on line. It’s where I found this but it may not be what you were after.

Cliveost · Post by **Cliveost** » Sat Oct 16, 2021 7:23 pm

Thank you I will take a look

Cliveost · Post by **Cliveost** » Fri Oct 29, 2021 7:55 pm

Further information. I have replaced the pipe with a new genuine one. It was very brittle when I removed the old one. In the meantime I have developed another fault. I’ve gained a missfire at tick over not all the time but reasonably often. I also have a smell when I park up that smells like a breathing engine. This does not necessarily happen at the same time as the missfire. My fuel mileage has dropped from around 35mpg to 26mpg. I’m wondering if this could be an injector fault and if that might cause the smell too. I do get a slight knock on picking the revs up when I have the missfire. When it’s running fine I have no knocking at all. Once the revs are over 1000 the engine runs smooth.

X5Sport · Post by **X5Sport** » Fri Oct 29, 2021 8:15 pm

You really need a code read to check the injectors for faults, though that normally brings up a warning message. Otherwise you need a tool to look at the live injection data to see if one is abnormal compared to the others. You may see a smooth running control message as well if the fault log is downloaded.

Cliveost · Post by **Cliveost** » Fri Oct 29, 2021 8:29 pm

I will check it tomorrow. I do not get the engine light on the dash when it missfires so not sure a fault will be logged but will check. Thank you

X5Sport · Post by **X5Sport** » Sat Oct 30, 2021 8:24 pm

Some issues will not trigger a warning light but should appear in the log. Others will sound every warning these cars have. I still don’t get the logic behind some of this stuff given the ease of sending messages to the alphanumeric displays in these cars! I suppose it keeps dealers in business and owners poorer

Cliveost · Post by **Cliveost** » Sat Oct 30, 2021 8:41 pm

I checked it today with BimmerLink but no faults in the system. I have tried to check the injectors individually but there is no option in the app for that.

Cliveost · Post by **Cliveost** » Sat Oct 30, 2021 8:42 pm

Does this engine suffer with injector problems?

X5Sport · Post by **X5Sport** » Sat Oct 30, 2021 9:28 pm

I don’t think that any specific BMW engines can be said to suffer from injector issues however we do see issues reported from time to time.

It may be that you need to do a ‘leak off test’ where the injector has fuel under pressure applied and held steady. It should not drip from the injector tip. If it does then that injector is in need of replacement.

Some diagnostic tools allow reading of live data whilst the engine is running and will show if any single injector has a significantly high (or low) flow rate when compared against the others. Any significant variation indicates an issue with that injector.

If that isn’t possible then it means either all injectors need removing or the car taken to a specialist who can run the tests. I think your engine has piezo electronic injectors. Those need specialist diagnostic hardware.

The description for the smooth running control is below:

Smooth running control

The smooth running control facility balances out the engine speed variations of the individual cylinders caused by different fuel injection rates and degrees of cylinder efficiency. This is achieved by quickly changing the fuel injection rates at each cylinder upon each injection. The DDE control unit uses the engine speed variations to calculate the correction quantities required to compensate for engine speed variations.

The maximum correction quantity for a single injection procedure by the DDE depends on the fuel injection rate.

Control is active within a specific engine speed and load range:

- Engine speed range: idle speed up to approximately 3500 rpm
- Load range: lower to medium load range.

Monitoring

If the correction quantities are not reached or are exceeded, the following faults can be stored:
Operational smoothness regulator, correction quantity too high/too low: The limit value for at least one cylinder was not reached or was exceeded.
Operational smoothness regulator cylinder X, correction amount too high/too low: The limit value at the cylinder X was exceeded or fallen below, while the correction amounts to the other cylinders were OK.

Cliveost · Post by **Cliveost** » Sat Oct 30, 2021 9:58 pm

Thanks I will hopefully be able to check the injectors on a laptop on Monday when I’m in work. We use 2 different Bosch injector specialists for testing and refurbishing so will give them a call too

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