An OBD nor BMW computer code will mean you are looking for 4 digits... so looking at 321d that is a evap system 'small' leak.

If the fuel cap is not loose, then it is a leak somewhere else in the syste,

A 'loose gas cap' is typically a 'presumptive' diagnosis. Worse case they ran codes, saw what it was and ASSUMED it was the cap. Reset, told you, that was it.

NOW they should do a test of the (a) gas cap and (b) rest of the evap system. There are 20+ little parts, fittings, clips, snaps,. etc that can cause this. Theyll need to do diagnostics.

9 times out of 10 they are right. THis time they look like idiots because they didnt tell you there was a chance they could be guessing wrong.

IMO

 

Thanks for replying ard. I thought that was presumptive too. I have checked the gas cap even before the first visit to the dealership to make sure that the gas cap was tight.

Now with all these info,
I know what to expect that they should do. That means much more than just erasing the code and blaming it on a loose gas cap that was never loose in the first place. I really appreciate it.

- BeemerX513

 

Thanks for replying ard. I thought that was presumptive too. I have checked the gas cap even before the first visit to the dealership to make sure that the gas cap was tight.

Now with all these info,
I know what to expect that they should do. That means much more than just erasing the code and blaming it on a loose gas cap that was never loose in the first place. I really appreciate it.

- BeemerX513

I wouldnt be too harsh on them. Just saying "look, I know it is usually the gas cap, and cant blame the tech for assuming that- but I did/do check the cap, even before the last visit- so this time lets do a complete work up, shall we?"

By showing you know a bit about the vagaries of car diagnosis, AND by showing you wont jump down their throats, you gain a bit of respect.

GL, report back

 

You are correct again Ard. I will keep that in mind. I didn't plan to jump on their throats anyway. Giving respect gets you respect. Thanks I'll let you know what happens.

- BeemerEx513

 

I wanted to report back regarding the status of my X5 concerning code 321D. First, I brought it to the dealership again. It stayed there for over a week. They replaced the tank ventilation valve around January 14. Here it is after a month, the check engine light came on again on February 14th.

By this time, I have already bought my own code scanner. I got the C110 BM code scanner, it is pretty sweet. The reading was there was a leak in the fuel ventilation system over 5mm. I will bring the X5 back to the dealership.

 

What was the outcome?