[taibanl]

Folks. After 65k my scr tank was replaced due to temp sensor failure.

Within a month i hd more codes for the system and urea leaking all over and it was determined to be a faulty transfer module.

Now i hear the pump running every time i stop the car (30s or so) it sounds like a fish tank pump- never had the sound before.

Is it normal?

[kbsilver]

I think it's normal. I could always hear mine.

[gavronm]

Agree. I've always heard mine when it's running.

[charlie fairmont]

This makes me wonder if I have a problem...I'm on my third tank now and the only sound any of them have ever made is the dash-light dong indicating they've died.

[Hoooper]

I hear mine pretty often after shut down also, always been that way

[335dwanted]

The SCR pump behavior was discussed on the other forum recently. Seems the SCR pump which pushes DEF to the exhaust injector reverses direction when the engine is shut down to evacuate the supply line (presumably to prevent freezing when cold, perhaps other good reasons as well).

I hear the humming every time I shut down. Have not paid enough attention to notice how long it runs.

[bvanlieu]

My OEM I could hear but faintly. After 60K or so the tank was replaced in the last year and the replacement one is more audible: you can hear the tank being purged what not every time I pull into the garage from a decent drive.

- b

[taibanl]

Thanks to all. Guess the original had more problems than i thought.