BMW 325 tds; Starts poorly when the engine is warm + Weak performance.

Hello, I hope someone of you can help me.
I have only driven VW TD or TDI engines so far and am not very familiar with BMW engines.

When the engine is warm, it starts poorly, and you have to 'crank' it for a while.
until it starts.

Furthermore, I would also be interested to know what weaknesses or problem areas these engines have!!!! What to watch out for!


Hoping you can help me.

Greetings

Hoping this helps.

http://www.motor-talk.de/t31949/s/thread.html


http://www.bmw-syndikat.de/bmwsyndikatforum/forum_print.asp?FORUM_ID=12

peter

Check the glow plugs, we had a case where it was the fuel injector pump. Cold started very well, warm started poorly.

Hello,

Generally, all temperature sensors and the battery are in question. We have experienced several TDI issues, primarily with MKB ALH, where the engine would only start poorly when the battery was partially discharged.

Thanks for the tips, I've also heard about the battery issue, I'll check that out.

Are there any other (typical) symptoms if the fuel pump is the problem?

I'm going to try glow plugs, but I'm surprised that it starts well even when cold.

syncro Peter: Thank you for your addresses, they were very helpful!!

Other potential weaknesses of this engine - turbo?

Hello,

My brother had a similar problem.

/viewtopic.php?p=45862

Should you need further assistance.

Best regards, Georg

Hello Chives,

As already suggested by a previous commenter, it would be advisable to check the extent to which your battery is still capable of performing well.

Furthermore, there are problems with the fuel pump in the tank related to your engine.
Within BMW, there is an instruction to install two backflow valves, one in the inlet and one in the outlet.
I've also given my 525tdS a similar treatment - the days of sluggish starts are over.

One way to check if this solution is right for you is to remove the second connector from the air intake bridge, looking from the side of the spray tank, and then let it warm up for a while before restarting. The connector is for the temperature sensor coolant, which is relevant for preheating.
You will see, at that moment, the heating element will be constantly active, while the pre-feed pump in the tank will start up, and the motor should immediately start.
It's probably going to be a bit rough, but the climate control also isn't working at the moment, but it should definitely be suitable for testing.

If needed, I can gladly provide you with the part number for the check valves. The friendly parts dealer will not find it in their inventory, as it is not listed there.

Otherwise, if the engine is both hot and cold, then you should be happy with the machine.
If you have any questions - ask!

Greetings, the Diesel Deer

That with the plug sounds good, hope it works.

The climate is also not running, is it possible that both symptoms (poor starting + no climate) are related to this plug???

Furthermore, I noticed yesterday that the engine is not properly responding to the accelerator when driving on the highway or when holding the accelerator pedal down for an extended period.

It accelerates up to a certain point (approximately 1/4 throttle) and then stops, even though the pedal is fully depressed!!!
Furthermore, it can be seen on the consumption display, which then increases in the 5th. Do not exceed 10 liters, otherwise, if everything is normal, approximately up to 18 liters.

Does this possibly have something to do with the (electrical) accelerator pedal?


Best regards,
Christian

Hello Chives,

'It is definitely possible that the climate problem and the poor warm-up behavior are related. On the other hand, it is preheated if necessary. Therefore, it is important to pay particular attention to the power supply, plugs, and (hopefully intact) cables that are hidden in the black electronic box under the air intake duct for the time being.

Regarding the issue with the 1/4-gas, if it passes smoothly in the other gears, does it only occur in 5th gear? If not, it could be that the vehicle is, in a sense, in emergency mode.

When was the fuel/air filter last replaced?

It would be helpful to have the error codes read (by a mechanic), I know that the availability of diagnostic equipment is limited in the BMW garages, BMW itself charges nothing for this, but you can pay around 5 euros to the mechanic.

If you were to do that, it would be a good idea. The data that the memory produces would be a good starting point for addressing the problems in an affordable way through the local discussion.
Errors should have been recorded for both issues.

Until then, greetings.
the Diesel Deer

Okay, I just unplugged it, and the indicator light then also lit up when the engine was warm. (So, the pump is also working).
After that, the car is quite well-behaved.

If my understanding is correct, then there must be air in the fuel system (perhaps a leak in the oil line?!)

'When I try to start it with a plug-in, I get the feeling that it only starts briefly, but then I have to keep trying until enough fuel is available!!'

Oil lines are, of course, also a possibility, often neglected, seemingly still in good condition, but completely hardened.
Would I have to do it from scratch - 12€ per meter!
Edit*: Currently, this cannot be the case either, as good cold start behavior indicates otherwise.

You can easily see the air in the system through the transparent hose from the KS filter to the pump. If you see a bubble moving there, then...

Greetings, the Diesel Deer

Furthermore, I noticed yesterday that the engine no longer responds properly to acceleration when driving on the highway or when holding the accelerator pedal down for an extended period.

It accelerates up to a certain point (approximately 1/4 throttle) and then stops, even though the pedal is fully depressed!!!
Furthermore, it can be seen on the consumption display, which then increases in the 5th. Do not exceed 10 liters, otherwise, if everything is normal, approximately up to 18 liters.

Does this possibly have something to do with the (electrical) accelerator pedal?


Best regards, Christian


It's been a long time, but this problem should still be a common occurrence - here's a solution, I just fixed it myself, and the same symptoms were present.

Sorry for my somewhat unprofessional description of the exact names of the parts:

Below the left strut mount, next to the AGR and radiator shutter valves, is also the turbocharger's boost sensor. Departing from this, a vacuum hose terminates in the intake bridge.
If the hose is damaged or no longer fits correctly, this described issue may occur. The control loop receives corrupted values. Small cause - big effect!

At the same time, the error is logged in the memory:

135 - Turbocharger Control Loop

I hope I was able to help!

Kind Regards, the Diesel Deer