[320D_germany]

I feel like :facepalm:

I have a 2001 320D with a manual transmission. When I accelerate slowly (on flat or an up hill grade), my car often has a moment around 1800-2000 rpm where the power disappears. The feeling is like the clutch was pushed in for a split second, like a hiccup. The rpms do not dip and the time laps is about a quarter to half a second. It does this most predominantly in 2nd and 3rd gear but can be felt in 1st as well. If I accelerate fast it does not happen (or it is not detectable). I switched the Mass air flow sensor without improvement. The fuel filter is also new.

As always these little problems you can not find an answer to are driving me :banghead:

 

[markusmarkus]

It sounds like you have a fuel delivery issue. When was the fuel filter last changed? See item #2 in the link.

http://www.realoem.com/bmw/enUS/showparts?id=AX71-EUR-01-2001-E46-BMW-320d&diagId=13_0650

 

[kaLinski]

OP mentioned the fuel filter is new.

However, I am experiencing the same symptoms at light load and suspect my filter as well (original filter, 197k miles, slap me now.)

 

[320D_germany]

OP mentioned the fuel filter is new.

However, I am experiencing the same symptoms at light load and suspect my filter as well (original filter, 197k miles, slap me now.)

Yes, my filter is new.

I have noticed this jerk happening more often, it even happened three times in a row within seconds. I have not had that happen again but it seems like a sign that it is getting worse. I am still monitoring it for now.

How can you test the fuel pump without buying a new one?

 

[kbsilver]

A bad coil (which is very common) can cause these symptoms, which is more noticeable at lower RPMs. With a code reader you may be able to see a pending misfire code which will make it easier to identify which cylinder (if that indeed is the issue).

 

[jfoj]

The problem here is the OP car is a DIESEL. They do not have ignition coils!

If this was a gasoline/petrol engine, I would say this clearly sounds like a DME ignition timing Map problem where the most recently DME update usually fixes the problem. But we are talking a Diesel with a DDE and no specific ignition timing Map because there is no ignition system.

I have no info on BMW Diesels and no first hand experience with them, but if there was some electronic fuel control that the DDE has the ability to alter, I would be curious if there is a problem with the DDE flash like the DME gasoline/petrol cars have to fix BMW's problem ignition timing Maps.

 

[jarjar]

You might need to rebuild your vanos? Any codes coming up?

 

[320D_germany]

This is territory I don`t know about. What is vanos? I do not have a code reader.

 

[jmo69]

I'm assuming there is a turbo, could be a boost leak, I've had trucks that blew an intake hose off and lost all power. It would be a place to start.

 

[jfoj]

Some turbo Diesels have vacuum pumps that use vacuum control boost and wastegate. There are probably electrically controlled solenoids that control vacuum or directly the wastegate and so forth. I believe the BMW Diesel has some form of "Swirl flap" that is kind of like the gas/petrol engine DISA.

 

[JJR4884]

coil or ccv would be a good thing to check, would be a handful of other issues however

 

[dmax]

If a local auto parts store can't read your codes for free (as they do here), you can get a bluetooth 'thing' to plug in and then get OBD Fusion App for $5 or so. Start with codes before you start throwing parts at it.

 

[markusmarkus]

This is territory I don`t know about. What is vanos? I do not have a code reader.

VANOS is BMWs term for variable valve timing.

 

[320D_germany]

Its been a long time since I posted this thread but I did get to a resolution which I want to share. There was a hose that comes from the turbo to the inter-cooler which delivers the air to the intake system. This hose had a big crack in it which was not easy to see. The air was blowing out the crack at peek turbo pressure and spitting oily air onto the wheel well and everywhere else too. After I changed the hose the "hiccup" problem went away but the lacking power remains. Ive started a new thread for my low power problem with the fault codes. I never had the codes before so this is a new insight.

 

[kaleemanwar]

I have a 2015 320d xdrive (F30). Today, had a full service done and EGR Valve cleaned but the hiccup problem in low gears is still there, especially in sport mode. Any suggestions?