[Kjelly]

With a lot of discussion on the EGR and its effect on the engine, I wanted to start a conversation on what people are seeing as they are driving.

Obviously, you'll need a OBDII monitoring device. I have the Scangauge II.

During the summer months, the EGR commanded activity would be holding steady at 94%, so essentially the valve is open, recirculating the exhaust.

However, during this month, especially during this past spell of temperatures below freezing, the EGR starts relatively closed at 25-50%. Even when the engine gets up to operating temps of 80-81C, the EGR holds around 60-75%.

This is different than what TDIwyse has seen, so I was wondering what anyone else has seen.

Side note: The EGR recall was performed approx. 20,000 miles ago.

[TDIwyse]

Regarding temp, the colder it gets, the lower the EGR "commanded %" would get on my car. Once ambient temps went below 0 F (think around -5 F or -10 F if I remember correctly) the stock EGR coding set it to 0%.

[WreckerX5d]

I have the scangauge 2 as well. How do you see the EGR settings? Did you have to program it into it, or was it already preset?

[TDIwyse]

Originally Posted by TDIwyse

Once ambient temps went below 0 F (think around -5 F or -10 F if I remember correctly) the stock EGR coding set it to 0%.

This was some of the first EGR data I logged. From the winter with stock vehicle. Looks like around 0F is where the EGR % started shutting off.

http://www.bimmerfest.com/forums/sho...6&postcount=25

Here's some EGR comparison of pre and post EGR recall. The recall caused much more EGR utilization on my vehicle. I didn't like the increased EGR utilization ...

http://www.bimmerfest.com/forums/sho...3&postcount=67

[TDIwyse]

Originally Posted by MonkUSMC

I have the scangauge 2 as well. How do you see the EGR settings? Did you have to program it into it, or was it already preset?

I'm not familiar with that tool. Using Torque or Bavarian Technic I can just see the EGR in the list of things to view...

[Mark M]

TDI or Hooper, would you be able to PM me or share on here the diode trick for reduced EGR? Thanks!

I've been monitoring my EGR command with the iphone app Engine Link. Been seeing usually 50 to 75% in the cold winter temps we have here in PA. Higher percentage happen when just cruising or at idle.

[TDIwyse]

Originally Posted by Mark M

TDI or Hooper, would you be able to PM me or share on here the diode trick for reduced EGR? Thanks!

I've been monitoring my EGR command with the iphone app Engine Link. Been seeing usually 50 to 75% in the cold winter temps we have here in PA. Higher percentage happen when just cruising or at idle.

http://www.e90post.com/forums/showthread.php?t=891797

Further testing showed it didn't really need to be a diode. A resistor worked as well. One thing I found was that it really only worked for a cold start. If the car is warmed up and shut off for a quick errand, subsequent starting wouldn't trigger the condition.

Let us know if you see a change.

[Kjelly]

Originally Posted by MonkUSMC

I have the scangauge 2 as well. How do you see the EGR settings? Did you have to program it into it, or was it already preset?

I think the EGR might have been an X-gauge setting. I'll check on my drive home

[dixy2k]

one of the "benefits" of the EGR valve is helping with engine warm up. It stays open when the engine is cold.

[Hoooper]

Originally Posted by TDIwyse

http://www.e90post.com/forums/showthread.php?t=891797

Further testing showed it didn't really need to be a diode. A resistor worked as well. One thing I found was that it really only worked for a cold start. If the car is warmed up and shut off for a quick errand, subsequent starting wouldn't trigger the condition.

Let us know if you see a change.

I had the same result. Engine would have to be off for a good chunk of time for the diode trick to work, at least an hour and maybe more. As far as a quick mod goes this is pretty good, I was seeing 40% max EGR so on the highway for me that was more than 50% less.

[Kjelly]

Originally Posted by dixy2k

one of the "benefits" of the EGR valve is helping with engine warm up. It stays open when the engine is cold.

That's what been said on these forums, but that's not the case from what I've seen the past few weeks. It's been the opposite, EGR commanded is near 20% until coolant gets around 50C and then EGR will further open to around 50-60%

[Kjelly]

Originally Posted by MonkUSMC

I have the scangauge 2 as well. How do you see the EGR settings? Did you have to program it into it, or was it already preset?

It's a "x-gauge"

Try
Commanded EGR(%)
TXD: 07E0012C
RXF: 0441052C0000
RXD: 2808
MTH: 006400FF0000
NAM: EGR

I have a few other others from Scangauge if you would like them. I gave them some info off the OBDII in the past, since they haven't worked with an actual 335d.

[TDIwyse]

Originally Posted by dixy2k

one of the "benefits" of the EGR valve is helping with engine warm up. It stays open when the engine is cold.

Interestingly (on my car at least) the EGR utilization was lower than normal (assuming you're not in extreme cold environments) at the beginning of the warmup phase (until coolant hits 140F) than after this temp (see 2nd link from my above post for plots). Think is due to the post injection being utilized until this point to help speed up warmup.

Examining the EGR cooler also revealed an interesting use of an internal "flapper valve" in the exhaust gas path. If you look at the cooler you'll see a little black vacuum diaphram that connects to a lever arm on the cooler. It can move the flap so that the exhaust gas hits or bypasses the coolant routing inside the EGR cooler.

From what I've seen, even with the stock programming and EGR/EGR cooler working as designed, my car wouldn't warm up to operating temps on my ~15 mile commute in temps below ~10F unless I blocked the front grills.

[Mark M]

I did some fishing on RealOEM this afternoon.

We've theorized that the X5D didn't suffer the carbon / soot buildup like the 335d because of the addition of a low pressure EGR on the X5.

Out of curiosity, I wondered what BMW did on the 2014 535d. It appears they have opted to only use a high pressure EGR, just like what we have on the 335d.

http://realoem.com/bmw/showparts.do?...82&hg=11&fg=50


However the EGR cooler is kept on the exhaust side of the engine.

http://realoem.com/bmw/showparts.do?...92&hg=11&fg=50

So unless they have found some other way to mitigate this soot / carbon buildup problem, one might speculate that the new 535d may also be prone to the same issues we have been seeing. I'll admit, I was hoping RealOEM would have unearthed some trick idea or smoking gun that could help all of us.


Edit - Likewise the new 328d only appears to have a single high pressure EGR.

http://realoem.com/bmw/showparts.do?...82&hg=11&fg=50

[135i_vs_]

Originally Posted by Mark M

We've theorized that the X5D didn't suffer the carbon / soot buildup like the 335d because of the addition of a low pressure EGR on the X5.

I wouldn't credit the LP EGR. It probably has more to do with the weight/loading conditions the X5 has.

[Mark M]

I installed a partial EGR block off plate. It is a stainless 1-1/4 inch fender washer with a 3/16 inch hole.

It is installed at the union of the EGR pipes under the fancy hose clamp

This does trigger a code but significantly reduces EGR flow. Coolant temps still seem to stay in ideal ranges.

[JDG]

Thats exactly what I did but blocked the hole completely. I get a code trying to figure out a real solution and hope I dont crack the egr cooler in the process.

[dixy2k]

Wouldn't that washer collect soot?

My guess is that if the hole was completely blocked there would be a higher pressure inside and the exhaust would go all out in the DPF. Path of less resistance.