[MillerMav]

Good afternoon all,

I joined this forum many years ago but never really had much to contribute or any questions to ask. So hello, again!

That being said I have an engine question. A friend of mine Matt Whitbread recently installed a JR race tune, Buzzken exhaust and AAR EGR delete on my 2009 X5. He told me to put my questions here as it gets more activity than the X5 forums.

After the install was complete I had zero power on the small turbo (nothing until it started coming on around 2600rpms). Matt replaced all the vacuum lines but it didn't help. After 2800rpm this thing screams! This morning I replaced both pressure converters and checked all vacuum lines. It did get better but still a lot of lag. Before I move on to replacing the switching valve I thought I would ask if there is anything else I should look for? Also I have a Carly app so what "dashboard" things should I be monitoring and would it be helpful to put some logs up as well?

The car runs but it does go right into "reduced power" and has a CEL to go along with it. Thank you all for your help in advance.

[335dsleeper]

Originally Posted by MavE92

Good afternoon all,

I joined this forum many years ago but never really had much to contribute or any questions to ask. So hello, again!

That being said I have an engine question. A friend of mine Matt Whitbread recently installed a JR race tune, Buzzken exhaust and AAR EGR delete on my 2009 X5. He told me to put my questions here as it gets more activity than the X5 forums.

After the install was complete I had zero power on the small turbo (nothing until it started coming on around 2600rpms). Matt replaced all the vacuum lines but it didn't help. After 2800rpm this thing screams! This morning I replaced both pressure converters and checked all vacuum lines. It did get better but still a lot of lag. Before I move on to replacing the switching valve I thought I would ask if there is anything else I should look for? Also I have a Carly app so what "dashboard" things should I be monitoring and would it be helpful to put some logs up as well?

The car runs but it does go right into "reduced power" and has a CEL to go along with it. Thank you all for your help in advance.

I had a faulty MAF that would kill the small turbo. Literally acted the same way you describe. Try unplugging and see if it helps.

[MillerMav]

Originally Posted by 335dsleeper

I had a faulty mad that would kill the small turbo. Literally acted the same way you describe. Try unplugging and see if it helps.

I'm assuming you mean MAF?

[335dsleeper]

Originally Posted by MavE92

I'm assuming you mean MAF?

Yea, sorry. Stupid auto correct

[MillerMav]

Originally Posted by 335dsleeper

Yea, sorry. Stupid auto correct

That would certainly be an easier fix. I'll give it a try!

[shnaggs]

Originally Posted by MavE92

Good afternoon all,

I joined this forum many years ago but never really had much to contribute or any questions to ask. So hello, again!

That being said I have an engine question. A friend of mine Matt Whitbread recently installed a JR race tune, Buzzken exhaust and AAR EGR delete on my 2009 X5. He told me to put my questions here as it gets more activity than the X5 forums.

After the install was complete I had zero power on the small turbo (nothing until it started coming on around 2600rpms). Matt replaced all the vacuum lines but it didn't help. After 2800rpm this thing screams! This morning I replaced both pressure converters and checked all vacuum lines. It did get better but still a lot of lag. Before I move on to replacing the switching valve I thought I would ask if there is anything else I should look for? Also I have a Carly app so what "dashboard" things should I be monitoring and would it be helpful to put some logs up as well?

The car runs but it does go right into "reduced power" and has a CEL to go along with it. Thank you all for your help in advance.

So the car was fine before the all the stuff was installed???

So wouldn't this be the second car that has had this kinda problem after tune/deletes??? aka Omahadiesel

[MillerMav]

Originally Posted by shnaggs

So the car was fine before the all the stuff was installed???

So wouldn't this be the second car that has had this kinda problem after tune/deletes??? aka Omahadiesel

No sorry I left out some detail.

Before the tune and DPF/EGR mods it was not fine. First off all the DPF was completely clogged and I had no power anywhere in the power band. I tried forcing regens through Carly with no success. I did not do this mod for the performance I did it for the cost save over a new DPF from the dealership. Also before the DPF issue I was having stuttering and lag issues during low RPM, small turbo, boost usage and random CEL's due to boost related issues. There were other problems and these mods plus the new pressure converters have certainly made what I currently have smoother than what it was at before.

What I am trying to find out is why I have no boost in the low RPM range. I haven't tried unplugging the MAF yet, I will do that tonight. I was talking to Matt and he suggested I talk to some people in here before buying the switch valve and tearing into that project as well.

[Andrew@FixMyVW]

Originally Posted by MavE92

No sorry I left out some detail.

Before the tune and DPF/EGR mods it was not fine. First off all the DPF was completely clogged and I had no power anywhere in the power band. I tried forcing regens through Carly with no success. I did not do this mod for the performance I did it for the cost save over a new DPF from the dealership. Also before the DPF issue I was having stuttering and lag issues during low RPM, small turbo, boost usage and random CEL's due to boost related issues. There were other problems and these mods plus the new pressure converters have certainly made what I currently have smoother than what it was at before.

What I am trying to find out is why I have no boost in the low RPM range. I haven't tried unplugging the MAF yet, I will do that tonight. I was talking to Matt and he suggested I talk to some people in here before buying the switch valve and tearing into that project as well.

Just had a car that sounded just like your situation

[Whitbread]

I unfortunately didn't have time to keep the X5 for further diagnostic testing in order to stay withing MavE92's pickup schedule as we're a good bit apart. You can hear the small turbo whistle properly upon startup when the turbine valve pulls shut, there was minimal oil in the charge piping and no oil in the inlet of the DOC/DPF. Seeing that, I don't suspect a blown hp turbo. The turbine valve actuator can does hold vacuum so there's no torn diaphragm.

I'll log my maf values and get some numbers to compare yours to. I'll be down your way august 5th or 8th and can stop by to swap maf's or other parts if needed.

[MillerMav]

Originally Posted by Whitbread

I unfortunately didn't have time to keep the X5 for further diagnostic testing in order to stay withing MavE92's schedule pickup schedule as we're a good bit apart. You can hear the small turbo whistle properly upon startup when the turbine valve pulls shut, there was minimal oil in the charge piping and no oil in the inlet of the DOC/DPF. Seeing that, I don't suspect a blown hp turbo. The turbine valve actuator can does hold vacuum so there's no torn diaphragm.

I'll log my maf values and get some numbers to compare yours to. I'll be down your way august 5th or 8th and can stop by to swap maf's or other parts if needed.

Thanks Matt. I will let you know if you need to swing by. It shouldn't be out of the way at all for you to come by. I will plan to have the switching valve swapped out by then just in case we need to do some further diagnosing.

[Whitbread]

FIXED!!! Stopped over to see MavE92 on my way home from Buffalo. We did some testing with a mityvac, swapped mafs, and still same. Decided to data log my car, then data log his x5 and compare. As soon as I looked at the screen shot of my "boost pressure value before correction" to his while at idle, I noticed his reported map was 255kpa at idle, not 100-103kpa as it should be. Swapped map sensors and now shows 102kpa at idle and runs perfect with full low end power!

So a map sensor incorrectly reporting can be now be added to the seemingly endless list of causes for loss of low end power LOL.

[MillerMav]

Thanks again man! I can't say enough good things about Matt and Whitbread Performance. Went out of his way about 90 minutes to stop by and swap parts between his 335d and my X5d. After a lot of test drives and head scratching who would have thought that the easiest and cheapest thing to change in the engine compartment would be the source.....?

Oh well. At least almost everything else is now new! It runs like a beast. I have never driven something so heavy, so fast! lol