Diesel Exhaust Fluid

[Da M3nace]

Hello ALL. I purchased a used 2010 X35d last December and had a question about the Diesel exhaust fluid. Does the ECU/Service monitor alert the driver when its time to change out this fluid. I read the manual and it shows that the fluid should be replaced every 2nd oil change but I am not sure when it was done last. I am due for my first oil change this month and I just had to refill the exhaust fluid with one bottle for the first time.

Also, how often do you guys replace the fuel filter in the diesel X5's?

Thanks!!

[joe_planet]

When the fluid gets low it starts a countdown from 1000 miles to zero at which point the vehicle will no longer start. You also don't change the fluid you add it.

[Da M3nace]

Originally Posted by joe_planet

When the fluid gets low it starts a countdown from 1000 miles to zero at which point the vehicle will no longer start. You also don't change the fluid you add it.

That makes a lot of sense. I must be confusing the fluids in question here but swear I read fluid changes every 2nd oil change for dEF.

[note46]

Originally Posted by Da M3nace

That makes a lot of sense. I must be confusing the fluids in question here but swear I read fluid changes every 2nd oil change for dEF.

Fluid is not changed. Rather it's replenished at every oil change or as needed.

I just bought a small bottle from a VW dealer for $8.95 vs $24.99 at the local BMW dealer.

[joe_planet]

I buy my DEF at walmart.. even though I dont like going there lol.

I can get a 2.5 gallon container for $12. I also have a f350 diesel truck that uses it, so I need to keep the costs down.

[BMW_Diesel_Owner]

How much DEF fluid would you need every month or every 6 months? The reason I am asking is the local store carries 2 large sizes. Although both are cheap, I don't want to overbuy, and end up storing the fluid for 10 years.

Do you use a gallon of this stuff twice a year?

[Da M3nace]

I added a full size bottle of DEF from dealer a month ago and About 300 miles ago the DEF alert came on again. Does this sound normal? I only put on about 1200 miles since last top off...

[Sylvan Lake V35]

Originally Posted by Da M3nace

I added a full size bottle of DEF from dealer a month ago and About 300 miles ago the DEF alert came on again. Does this sound normal? I only put on about 1200 miles since last top off...

Did you add to both tanks? I added to both tanks and it took two huge jugs.

[Da M3nace]

No. I read manual and didn't realize there were two points to fill. But why did alert go away first time if it wasn't full?

[thompsw]

My "miles to empty" is at 3000 and I've topped up the DEF. Does anyone know if this will reset itself driven by a sensor or if I can reset it somehow ?

I presume that whatever this counter says, I won't have problems with the level until the sensor actually thinks that I'm running < 1000.

Thanks !

Dave.

[Da M3nace]

My sensor has reset it self both times I have added a bottle of def.

[thompsw]

Originally Posted by Da M3nace

My sensor has reset it self both times I have added a bottle of def.

Thanks for the response -- has the mileage counter reset itself, i.e. the one that shows up for a few seconds after you turn the engine on, or just the warning sensor ?

Thanks !

Dave.

[Da M3nace]

The warning sensor that displays mls to empty/no start.

[thompsw]

Originally Posted by Da M3nace

The warning sensor that displays mls to empty/no start.

Ok, thanks. What happens with the countdown that appears when the car is started ?

[serge1]

Originally Posted by thompsw

Ok, thanks. What happens with the countdown that appears when the car is started ?

That one is probably a countdown until next oil change. Does it show something like 8,000 miles?
DEF refill countdown should disappear from iDrive and console displays when car is started.

[BMW_Diesel_Owner]

I refilled the DEF fluid on my X5 this morning! First thing to keep in mind is that the active reservoir is pretty much filled up by the passive reservoir. You can try topping it up, but it's better if you just top up the passive reservoir, which is located under the air intake.

VERY IMPORTANT: You probably need about a gallon to fill up the passive reservoir. However, using the humongrous-size DEF fluid will likely end up you spilling all over the engine area, so plan properly by putting rags all over the adjacent area. Also, you should use a funnel.

[thompsw]

re countdown - the DEF countdown does disappear. That's the one that hasn't changed with me filling up the reservoirs. When I bought the car (used) it was at 7000. It was showing 3000 when I filled up the reservoirs and still shows 3000. I'm guessing at this point that it's not something that I can change unless someone tells me otherwise. The oil change countdown is visible through iDrive and it's a lot higher.

re filling with funnel - the DEF that I bought came in a box with a faucet and long hose. I let it trickle into the reservoir until it filled; didn't spill. Not having any way of judging how much room I had in the tank, that seemed safest. I had assumed that since the DEF countdown was down to 3000 that I had lots of room for DEF ... bad assumption ... lucky I let it trickle or I'd have spilled a lot of the crap, funnel or no funnel !

Dave.

[Sylvan Lake V35]

Mine also came with a nozzle in the box and both of my tanks required filling, it is possible my passive was empty causing the active level to drop? Anyway my local Indy tried just filling the active and I made him fill the passive as well and it took about 20L to do both tanks. Which is way more than either of us thought it would take so he had to have more delivered. Unless he reset the light before I got there it reset itself when filled.