Oil Change - Car not happy when hot

[rb0135]

Originally Posted by chas3

RealOEM.com * BMW E53 X5 3.0d Hot-film air mass meter

I didn't quite read through the whole thread, but is this a cold start only behavior? Or the engine operating temperature doesn't matter? Cause a faulty MAF would cause issues no matter the operating temperature.

Hi Chas3.

No, it is only a HOT issue. When cold, car is perfect. Once operating temperature (hot engine) lack of power, revs drop after gear change, although accelerator in same position and a few other symptoms mentioned.

Thanks for the link and info on the MAF. I have been looking at Realoem trying to find it.

Rob

[chas3]

Got it. Kinda awkward that it doesn't throw any error codes on your DIS or INPA. It does sound like a faulty MAF, but for instance, a faulty injector could cause a similar behavior. I guess you could borrow one from a fellow 3.0d owner and see how the car behaves, to make sure this is the culprit, before you throw $100+ (at least in here) at it.

[rb0135]

Originally Posted by chas3

Got it. Kinda awkward that it doesn't throw any error codes on your DIS or INPA. It does sound like a faulty MAF, but for instance, a faulty injector could cause a similar behavior. I guess you could borrow one from a fellow 3.0d owner and see how the car behaves, to make sure this is the culprit, before you throw $100+ (at least in here) at it.

Thanks.. I wish it would throw codes (ones that would help I mean)..

I thought of injectors but they have been tested (by the mechanic that says to change the fuel filter as that is the problem) and people keep telling me if it was an injector, i should at least see some codes in DIS (the only codes I am seeing is from the NAV retrofit I did a few weeks ago and havent got around to coding that)..

The fact when I disconnected the EGR vacuum pipe, there was a noticable difference, could point to both being/becoming "faulty". I did read somewhere, a lot of people have had faulty EGR Valves on the X5 Diesels, after about 60K miles (100K kilometres) which I am up to 91K kilometres.

I might take both off and clean them out with the proper cleaning products and see if that helps.. I suppose that can hurt, and the MAF in the diagram from REALOEM is only held in by two screws. It might end up being a "quick" job. If the MAF was faulty, one would presume it would through a code???

Thanks, Rob

[chas3]

Oh well.. most are shots in the dark, especially without seeing the car. The simplest approach would be to run INPA and get some live data of the engine and gearbox if automatic, parameters while the erratic behavior occurs. Then you can go from there.

Regarding the EGR valve, it can get clogged even sooner then those 60k miles. Even if that is not the real culprit, I would clean it up anyway. As about the fuel filter, it usually causes a sluggish behavior only, not erratic RPMs; we change it at around say 10-15-20k km at most in here, due to awful diesel fuel quality.

MAF cleaning usually ends up with MAF damage. I would rather go the INPA way, then attempt to clean it.

[rb0135]

Originally Posted by chas3

Oh well.. most are shots in the dark, especially without seeing the car. The simplest approach would be to run INPA and get some live data of the engine and gearbox if automatic, parameters while the erratic behavior occurs. Then you can go from there.

Regarding the EGR valve, it can get clogged even sooner then those 60k miles. Even if that is not the real culprit, I would clean it up anyway. As about the fuel filter, it usually causes a sluggish behavior only, not erratic RPMs; we change it at around say 10-15-20k km at most in here, due to awful diesel fuel quality.

MAF cleaning usually ends up with MAF damage. I would rather go the INPA way, then attempt to clean it.

Ok.. Thanks for all the info.

I think since the EGR showed differences, I'll start there (being the cheapest to get some carb cleaner and clean it). i will move onto the MAF after that.. better do one thing at a time, or I will never discover what fixed the issue (if I ever get it fixed).

Rob

[powers1]

Originally Posted by rb0135

Ok.. Thanks for all the info.

I think since the EGR showed differences, I'll start there (being the cheapest to get some carb cleaner and clean it). i will move onto the MAF after that.. better do one thing at a time, or I will never discover what fixed the issue (if I ever get it fixed).

Rob

Rob,
We get here quite a few X5s and X3s 3.0D with same symptons as yours,even under warranty!Only difference is ,they come in with EML on and after we perform diagnostics,90% of the time its the EGR solenoid that brings up the error.First test we do(yes..you guessed it),is disconnect the vac pipe.Then we replace solenoid..problem solved!
Cleaning the EGR valve wont do any harm but thats not the problem,because you have proved that with vac pipe disconnected ,the car is fine.With the pipe disconnected ,the egr is closed (no exhaust gases to inlet !) and although it may not be sealing 100%,its seems to be shut enough for it not have an influence in the cars performance.
What opens/closes the EGR valve is the ECU from instruction from EGR solenoid,so this would be be your first suspect

[rb0135]

Originally Posted by powers1

Rob,
We get here quite a few X5s and X3s 3.0D with same symptons as yours,even under warranty!Only difference is ,they come in with EML on and after we perform diagnostics,90% of the time its the EGR solenoid that brings up the error.First test we do(yes..you guessed it),is disconnect the vac pipe.Then we replace solenoid..problem solved!
Cleaning the EGR valve wont do any harm but thats not the problem,because you have proved that with vac pipe disconnected ,the car is fine.With the pipe disconnected ,the egr is closed (no exhaust gases to inlet !) and although it may not be sealing 100%,its seems to be shut enough for it not have an influence in the cars performance.
What opens/closes the EGR valve is the ECU from instruction from EGR solenoid,so this would be be your first suspect

Thanks Powers1 again..

Ok, i hear ya.. leave the MAF alone... Good, it looks like as job and a half to do anything with it anyway.

I will work on the EGR. I will clean it (just to remove the junk which I am sure it will have). I have tried to trace the vacuum tube back to the control unit (according to the realoem diagram, there is a small control unit, which I presume you are referring to is the solenoid (part #1 in RealOEM.com * BMW E53 X5 3.0d Vacuum control-AGR)

Is this correct? or do you mean in the EGR unit itself?

I think i would rather fix it than have the pipe disconnected.

However, I will leave it disconnected for the short term (might be a week or two before I get a chance to clean and get the part needed), so that will be a good test.

Thanks for everyones help. I am so relieved I actually know the area of the fault.

Rob

[powers1]

Originally Posted by rb0135

Thanks Powers1 again..

Ok, i hear ya.. leave the MAF alone... Good, it looks like as job and a half to do anything with it anyway.

I will work on the EGR. I will clean it (just to remove the junk which I am sure it will have). I have tried to trace the vacuum tube back to the control unit (according to the realoem diagram, there is a small control unit, which I presume you are referring to is the solenoid (part #1 in RealOEM.com * BMW E53 X5 3.0d Vacuum control-AGR)

Is this correct? or do you mean in the EGR unit itself?

I think i would rather fix it than have the pipe disconnected.

However, I will leave it disconnected for the short term (might be a week or two before I get a chance to clean and get the part needed), so that will be a good test.

Thanks for everyones help. I am so relieved I actually know the area of the fault.

Rob

Hi Rob,
Yes ,its part number #1.
If you get to it,see if you can get a digimeter connected to the electrical plug and measure the resistance (ohms).
Like I said before ,its no problem having the vac pipe disconnected ,at least this way you dont get anymore "gunk" into your engine.
Its this gunk that sticks to 2.0D and 3.0D that have the swirl flaps in the inlet and blocking them.
At least now ,you know what the problem is and you can sort it yourself.

[Lookin4Trouble]

Have you checked your glow plugs yet? I never saw that going anywhere above... I changed out my spark plugs and that got rid of the lurching issue almost entirely, throttle response seems better at lower RPMs, etc...

E

[chas3]

It's a diesel.