[Yozh]

This may have hit this forum before, but I thought it would be interesting:

[Oo vvR3cKz oO 619]

[BB_cuda]

Very good of you to share this, yohz. I always wondered why oil got dirty so quickly. Yet another reason to shit can the EGR.

Does anyone know if BMW uses differential pressure vs mileage to start a regen? The more I read and learn here, I am so glad to be doing the engine mods quite soon.

[Yozh]

Differential pressure. At least there are a bunch of parameters related to that in the BMWHat app.

[Yozh]

I like how the presenter in the video says that he would be a millionaire designing and retrofitting aftermarket DPFs into some ill conceived truck systems. Just shows how crappy some systems are just to satisfy emissions.

Also, did anyone pick up him mentioning injector issues?

[TDIwyse]

Originally Posted by BB_cuda

Does anyone know if BMW uses differential pressure vs mileage to start a regen? The more I read and learn here, I am so glad to be doing the engine mods quite soon.

Page 133 of the BMW Diesel Tech pdf

The DDE will initiate regeneration every 300 to 500 miles depend- ing on several factors. Mostly, the regeneration is transparent to the driver. There may be a light loss of power for a short period while the soot is burned off.

It used to go off every ~400 miles like clockwork on my car. Maybe 450 on a long continuous highway drive. But daily driving back and forth to work it was 390-400 miles and then another regen...

[335D Alpha Pappa]

Originally Posted by TDIwyse

Page 133 of the BMW Diesel Tech pdf

The DDE will initiate regeneration every 300 to 500 miles depend- ing on several factors. Mostly, the regeneration is transparent to the driver. There may be a light loss of power for a short period while the soot is burned off.

It used to go off every ~400 miles like clockwork on my car. Maybe 450 on a long continuous highway drive. But daily driving back and forth to work it was 390-400 miles and then another regen...

What does this sound or feel like? I drive 800+ miles a week and never noticed a regen. Depending on how much fuel this uses, it might explain why I have noticed the mileage dip on my mpg calculations every couple of fuel ups.


So glad I do not have any of this crap on my Dmax. No DPF, egr, scr, etc etc and no CBU.

[Pierre Louis]

Originally Posted by BB_cuda

Very good of you to share this, yohz. I always wondered why oil got dirty so quickly. Yet another reason to shit can the EGR.

So says this Amsoil salesman, with no data - only anecdotes. His percentages and generalizations are not supported. That doesn't mean that there isn't a strong concern about soot accumulation or oil/fuel quality. Too bad we don't see a real engineer do this.

PL

[WreckerX5d]

Originally Posted by 335D Alpha Pappa

What does this sound or feel like? I drive 800+ miles a week and never noticed a regen. Depending on how much fuel this uses, it might explain why I have noticed the mileage dip on my mpg calculations every couple of fuel ups.


So glad I do not have any of this crap on my Dmax. No DPF, egr, scr, etc etc and no CBU.

There isn't a sound associated with a regen. If you monitor your MPG gauge under the tach, during a regen cycle your MPG's drop considerably faster for about 20mins. This is the way I can tell it's going on. Easiest during highway driving.

[dixy2k]

When you park your car and the engine fan is on, you are in the middle of a regen. And that's a bad thing. There is no warning.
Get a OBD2 monitor.

[Crawler]

Originally Posted by dixy2k

When you park your car and the engine fan is on, you are in the middle of a regen. And that's a bad thing.

How do you know you are in the middle of a regen and not just the cooling response to a regen that is complete?

Why is this bad?

Cheers,

J

[Hoooper]

You can tell its running if you're cruising on the highway because the instant mpg meter will show way worse mpg than usual. Can also tell because there is noticeably less power and more struggle at light pedal application.

[bagman]

With an investment of $10 in an OBD2 to Bluetooth device and $5 in the Torque Pro Android app you can have your phone tell you when a regen is happening. When the app installs it also installs a woman in your phone and you can program her to tell you when your exhaust gas temp gets above a set temperature. My D usually exceeds 1100°F when regening. I've set her to tell me when the temp gets to be 900°. I will occasionally get a half hearted attempt at a regen where the temp will reach around 900 for a couple minutes and then drop back to normal which is around 400 to 500. She doesn't pronounce regen right but you'll know what she is talking about.

[dixy2k]

Originally Posted by Crawler

How do you know you are in the middle of a regen and not just the cooling response to a regen that is complete?

Why is this bad?

Cheers,

J

Because the temp drops immediately after the regen is over.
When you stop the engine at 1200F, you are essentially baking your turbo.

When I had my SCR replaced there was significant diesel fuel inside, which obviously was not burnt during regen. I had no way to tell in the past when my regens would take place and as I drive in the city a lot and for short distances (2-5 min trips) the regen would not complete.
A lot of times during 60F outside temps I thought the engine was running too hot.
It turned out the regens were abruptly stopped by me when turning off the engine.

Now I have my torque app and get on the freeway immediately as I notice the regen is taking place. I also estimate when it will take place and plan my day ahead of time so I can get on the freeway when needed.

[Vreimann]

Originally Posted by dixy2k

Because the temp drops immediately after the regen is over.
When you stop the engine at 1200F, you are essentially baking your turbo.

When I had my SCR replaced there was significant diesel fuel inside, which obviously was not burnt during regen. I had no way to tell in the past when my regens would take place and as I drive in the city a lot and for short distances (2-5 min trips) the regen would not complete.
A lot of times during 60F outside temps I thought the engine was running too hot.
It turned out the regens were abruptly stopped by me when turning off the engine.

Now I have my torque app and get on the freeway immediately as I notice the regen is taking place. I also estimate when it will take place and plan my day ahead of time so I can get on the freeway when needed.

When I stop the car and fan starts, I just get back into the car and idle for a while. The car will prematurely stop the regen and pick it up at a later time.

As long as you remember that you left it in the middle then you can take a longer higher speed route to finish the regen.

It would have been nice if there was a warning regen light to give some warning other than bad fuel economy.

[dixy2k]

It needs to be done at constant speed/RPM.
If you look at the EGT and EGR command during city driving while having a regen taking place, you will notice the parameters are not where they should be as the speed and RPM fluctuate.

[locolobo]

That's good to know about the fan running when the car's off. Mine has done it several times and I just assumed the car was hot and needed to cool down. I don't recall reading about that in the owner's manual.

[Hoooper]

Aside from during a regen the only other time the fan has run in mine is driving in town when its 95 or hotter and the a/c is on. Otherwise the fan never runs.