No pull at low revs

[benh0218]

Hey All

Newbie to the group here.

I have an E70 X5 (2007) 3.0d with just over 100k miles on the clock and I am having some challenges with it pulling at low revs, often having to floor the accelerator until it gets over 2000 rpm and then it starts to pull properly. It had a dpf fault end of last year when the car went into limp home mode whilst on a long drive and with grey smoke coming out the back. In the end, we wound up having to be recovered. Took it to the local garage, they "cleaned" the dpf and told me to take it on a long drive at 3000 rpm to see if it regenerated - no such luck. I've been putting off sorting it for a few months, but now want to get to the bottom of it, as I'm fed up of the lack of punch.

The codes I'm getting are: 3FF0 Air Mass Flow Sensor, 452A Particulate Filter System, 4667 Particulate Filter System and 4501 Exhaust Gas Recirculation Control Deactivation. The air mass code is new, the other 3 were present from when the problem started.

I found the hidden menu in the dash tonight and took it for a quick run to see if the engine was getting up to temperature. 15 mins of high rev driving got the engine up to 80 degrees C, so don't think there's any issue with the engine getting up to temperature to run a regeneration.

A friend has offered to take the dpf off and remove the internals, then code out the faults, but I wanted to explore other options first if there is an easier solution.

Thanks for taking the time to read my first post and any help would be massively appreciated.

PS - once upon a time I served my time with Audi, however left the trade shortly after finishing my studies. Although this was some 15 years ago, I do still have a reasonable working knowledge of how cars are put together.

Cheers,

Ben

[Alan Gunn]

Needs to be over 80c so that is a thermostat problem to start with as the stat should open at 82c so i would get both if you have 2 stats changed for a start.
Do that clear the codes and see what comes back plus give it a good run.
Also check all the thin vacuum pipes as well as they will be failing at that age now,

[X5Sport]

It could also be a glow plug issue as without those all working the regen won’t happen. Worth checking that they are all working (and the controller) even with no fault being recorded.

Temp looks low too.

I hope that your friend told you that removing the DPF is an automatic MOT failure now as well as making the car illegal on the road. Soot on the tailpipe ends is a dead giveaway.

[Leslie]

I'd agree the stats need changed you do not have to rev hard to get up to temp and it should happen in about 5 mins in summer I'm guessing with gentle driving it's more like 65c.
You have more than one issue by the look of it no pull at low revs is possibly the variable vanes on the turbo are not moving so no low down go and as said a vacuum line has possibly split to the turbo.
As for gutting the dpf internals but putting the case back to fool mot I'd try and avoid that as well.
Finding the cause of no power at low revs may fix the particulate filter fault as they may just be symptoms....
452a seems to be to do with dpf Ash mass which is a way they calculate how long a dpf will last by as buildup, I heard people get this about 160k but if you use software to tell the car it's just had a new dpf it will be OK again....4667 looks like regen too frequent which suggests the regents are not working properly ossibly due to low engine temp etc.
Oh and welcome.

[benh0218]

Thanks a lot for your input gents. Going to replace the stat to start with - there's one on the EGR and one for the engine - should I replace both? Will check all vacuum hoses too.

Think I'll leave the dpf mod, sounds too risky.

[X5Sport]

If you’re pulling things apart then do them both in case you have to repeat the process to replace the other one.

[benh0218]

Hey guys.

Short update and a cry for help!

So, having replaced both thermostats, the coolant one was easily identified as faulty. However, regardless of taking the car on a long drive (50 mins at 65 mph) and easily achieving 90 degrees of temperature, the dpf will not re-gen. I read a trick on another forum about using a "sacrificial hose" so that the car reads 5mbar at idle. You may have read about that tip too, however it didn't work either.

On the 50 min test drive, I had a co-pilot erasing the codes as they came up, as I'd read this was the way to get the dpf to re-gen.

The codes I am still reading are 480A Particulate Filter System, 452A Particulate Filter System, 4501 Exhaust Gas Recirculation Control Deactivation and 3FF0 Air Mass Flow Sensor.

At this stage, I just want to re-gen the dpf so that I can see if the lack of pull at low revs is related or if I need to be looking at something else. I visually inspected the vacuum hoses for the turbo and can't see any degradation there, so I'm a bit stumped if I'm honest.

Any guidance would be greatly appreciated, as my MOT is due in a couple weeks and I'd like to have it running properly by then.

All very frustrating..........

[Alan Gunn]

What did you do about the Air Mass Flow Sensor.

[benh0218]

Nothing as yet, you reckon I should replace the Air Mass Meter as a matter of course anyway? Is it likely that a lack of low end pull would be because of that? I recall having to replace loads of those under warranty on the 1.8T 20v VAG engines (from the S3 and TT especially). I never diagnosed the fault with them though, they just arrived with a job card and I replaced the part (modern day mechanics) lol.

I'm now wishing I'd done more diagnostic work when I was in the trade - that's where all the skill is.

[X5Sport]

Some comments on line also suggest a coked up manifold & egr can cause the MAF error. Have you looked to see how badly crudded up they are? With an egr issue showing up that might be the problem. It could still be the MAF but you’ll probably need to use the DIS BMW diagnostics software to check it.

Diagnostics is a bit of a black art (or is that dark art these days?) and a good diagnostician is worth their weight in Platinum.