[bimmerdiesel]

After scanning for codes I found 2
46B7 : Swirl-flap actuator
and 4873: Exhaust gas recirculation cooling, plausibility

Cleared all codes and drove around for a bit. Got 4873 again but SES was not lit. Car drives fine.

History:
I was on a work trip (600 miles). During my trip, fan would continue to run after switching off the engine. I thought it must be going through its cycle but towards end of the trip SES light came on.
I had CBU done at 71k miles and now it is at 93k. I dont think its CBU. It is out of warranty so not going to go to dealership

I am taking it to local mechanic next week but he is not very diesel knowledgable.

I will monitor codes before taking it to mechanic. In mean time any initial thoughts.

[BB_cuda]

You may be paying for non diesel mechanics learning of M57. Might be better off going elsewhere that knows TDI at least.

[montr]

If you have a 335d, code 4873 is likely from a broken spring on the bottom of the EGR cooler. The spring is round and sit at bottom of the vacuum activated flap valve in EGR cooler. The spring cannot be replaced, you have to replace the whole EGR cooler. The spring is behind #6 and #7 in this picture.

[335stoner]

If you know the mechanic and you trust him why not ask him if he can work out a decreased labor rate deal. To help him learn a bit and that helps you out a bit. That could help him expand his knowledge

Keywords know and trust

[charlie fairmont]

I had the broken spring montr mentioned. You won't necessarily be able to see it's broken without removing the cooler. To check it while the cooler is still installed, try to move the arm by hand. If you can't move it, it's broken. I had one of the top coils of the spring break and lodge itself in between the arm and the rest of the spring. It looked fine from up top but the arm wouldn't move. I made a bobo repair with a ziptie and a spring from Ace hardware after getting the broken piece of spring out. I connected the spring to where the actuator arm snaps onto the egr cooler arm. I ziptied the other end of the spring to the coolant pipe near by. Seems to be working. No codes or ses lights since. Later, I bought a used egr cooler but have yet to install it. Ziptie and spring: roughly $4. Used cooler: roughly $100. New cooler: roughly $600, if memory serves.

[bimmerdiesel]

Thank you for all inputs. I read all night about 4873 and figured it has to do something with spring. I am going to see local bmw mechanic and make a call. I am considering doing it myself. Car is paid for and still runs and looks like new so why get another car payment.

During my research I came across this video. It looks like a good starting point.

I live in state without emissions so I will start researching on delete options.

[dmanb2b]

I have a used cooler, if you end up needing one, PM me

[BB_cuda]

I cut up a bad cooler for the boss that goes on the input end. My point is i may have the spring that you need. I need to go look at my storage place and see. I recall cutting it up to see the heat exchanger. I am unsure whether the spring got cut too or not. If i find it and its good, it is your's for FREE.

[BB_cuda]

Spring found and it's unharmed.

[BB_cuda]

Upon further review, I'm at a loss of how to remove spring. That is other than cutting the top of the spring loaded shaft off. My point is I have no clue how you will reinstall this.

This may be why you can't buy spring by itself. I'll cut it out if you want.

[bimmerdiesel]

No worries. I wish design was simpler but thanks for trying. I still have to confirm that the problem is with spring and not something else. I am planning to open it up next weekend

Originally Posted by BB_cuda

Upon further review, I'm at a loss of how to remove spring. That is other than cutting the top of the spring loaded shaft off. My point is I have no clue how you will reinstall this.

This may be why you can't buy spring by itself. I'll cut it out if you want.

[bimmerdiesel]

Update:

Took it to local workshop and no codes. I did not drive for a week so took it for a drive(50miles) and still no codes. It doesn't look like problem is with EGR cooler spring.

In any case I started acquiring tools required to open it up so that I can check existing build up.