BMW X5 E70 3.0d bad fuel consumption

[david2047]

Hey guys,

Does anyone one know why my car (07 BMW X5 E70 3.0d, 136,600km) has a really bad fuel consumption (15-16L/100km)?
Even I drive on a highway, it is still about 15L/100km.
I tried to reset the fuel consumption several times but I still got the same fuel consumption.
The engine light is on (yellow) when I power up the battery, but after I start the engine, it is off.

BMW dealer said they found faults with cylinder 3,4,6 glow plug and suggest replace all glow plugs and control unit, I'll replace all of them myself later.
I'm also gonna replace the fuel filter later.

I just wonder will the fuel consumption be about 11L/100km or better after the replacement?
I've already replaced the air filter and changing the engine oil (5W-40, full synthetic) and oil filter, it doesn't help to improve the fuel consumption.
Does anyone have a diesel X5? Could you share your fuel consumption with me?

Cheers

[newfort]

Originally Posted by david2047

Hey guys,

Does anyone one know why my car (07 BMW X5 E70 3.0d, 136,600km) has a really bad fuel consumption (15-16L/100km)?
Even I drive on a highway, it is still about 15L/100km.
I tried to reset the fuel consumption several times but I still got the same fuel consumption.
The engine light is on (yellow) when I power up the battery, but after I start the engine, it is off.

BMW dealer said they found faults with cylinder 3,4,6 glow plug and suggest replace all glow plugs and control unit, I'll replace all of them myself later.
I'm also gonna replace the fuel filter later.

I just wonder will the fuel consumption be about 11L/100km or better after the replacement?
I've already replaced the air filter and changing the engine oil (5W-40, full synthetic) and oil filter, it doesn't help to improve the fuel consumption.
Does anyone have a diesel X5? Could you share your fuel consumption with me?

Cheers

Have you checked the EGR system - valve, cooler spring? I believe these could affect the mileage as well. Besides the glow plug codes, have any other codes popped up?

[david2047]

Originally Posted by newfort

Have you checked the EGR system - valve, cooler spring? I believe these could affect the mileage as well. Besides the glow plug codes, have any other codes popped up?

Hi newfort

I didn't check the EGR system, how to check them?
But I believe there is a problem with the EGR valve
As there is a "duck" noise come from the engine room,
which is exactly same as this post
https://www.e90post.com/forums/showthread.php?t=842393
I will replace the pressure convertor (11747796634) later, then I reckon the noise will be fixed.
Does the pressure convertor affect the fuel consumption?
What tools do I need to scan a code?

[newfort]

Originally Posted by david2047

Hi newfort

I didn't check the EGR system, how to check them?
But I believe there is a problem with the EGR valve
As there is a "duck" noise come from the engine room,
which is exactly same as this post
https://www.e90post.com/forums/showthread.php?t=842393
I will replace the pressure convertor (11747796634) later, then I reckon the noise will be fixed.
Does the pressure convertor affect the fuel consumption?
What tools do I need to scan a code?

Hi david2047,

Sorry, don't have insight into the pressure convertor and the noise you are experiencing.

Before you begin to tinker with the EGR valve and/or cooler, I would invest in a scanner (if you don't already have one). I personally use Foxwell NT530 and it has been good so far. This way you can check for any codes to diagnose the actual issue. For all you know the EGR could be perfectly fine and the problem might be somewhere else.

A lot of folks also use ISTA software to diagnose and run specific tests.

[Clavurion]

Glow plugs won't change the consumption. That "duck noise" is typical for a failed EGR vacuum solenoid like you already figured out. If you don't have diagnostics check the engine coolant temp on cluster hidden menu. It should be near 90 C. Low running temps can make consumption worse and eventually causes problems with DPF.

[david2047]

Originally Posted by Clavurion

Glow plugs won't change the consumption. That "duck noise" is typical for a failed EGR vacuum solenoid like you already figured out. If you don't have diagnostics check the engine coolant temp on cluster hidden menu. It should be near 90 C. Low running temps can make consumption worse and eventually causes problems with DPF.

Cheers mate
I'll check it later

[david2047]

Originally Posted by newfort

Hi david2047,

Sorry, don't have insight into the pressure convertor and the noise you are experiencing.

Before you begin to tinker with the EGR valve and/or cooler, I would invest in a scanner (if you don't already have one). I personally use Foxwell NT530 and it has been good so far. This way you can check for any codes to diagnose the actual issue. For all you know the EGR could be perfectly fine and the problem might be somewhere else.

A lot of folks also use ISTA software to diagnose and run specific tests.

Cheers mate
But I probably won't buy the scanner as it's about $200 and I may only use it one or two times...

[acidgreeny]

The scanner will save you thousands , if you own a BMW you own a scanner.

[sunny_j]

does the thermostat get up to temp?
I doubt the glow plugs are bad. replacing the module should get rid of all glow plug related codes

to test vacuum components check out the videos on this YouTube channel. it focuses on the m57 motor
https://www.youtube.com/user/alphadevyat/videos

[david2047]

Originally Posted by Clavurion

Glow plugs won't change the consumption. That "duck noise" is typical for a failed EGR vacuum solenoid like you already figured out. If you don't have diagnostics check the engine coolant temp on cluster hidden menu. It should be near 90 C. Low running temps can make consumption worse and eventually causes problems with DPF.

Hey mate,
I've checked the coolant temp on the hidden menu
With a 5 mins drive (~50km/h) in the city, the coolant temp is about 64 C
https://imgur.com/68s3I8S
I'll take a 20-30mins (80km/h) drive on highway tmr, and update the temp again
I'll also change the coolant recently


Apart from that, the exhaust of my car smell so bad, when I start the engine and left the car I can smell something bad from the exhaust, but don't have any smoke come out