Went out tonight but did some logging of exhaust temperature as I believe a definite signal for a regen is when your exhaust temperature rockets from 300ish to 5/600 and also the coolant temp.

EGR stat is knackered, hovered in the 70's only got to 80's on town roads but shoots back down on 40mph+ roads. Exhaust temperature peaked around 350ish so no dpf regen I don't think and occasionally I read the DPF status and one thing I don't get is, I did one or two WOT and it went up quite quick from 38g soot to 41/42/43 but then as I come back down to normal speeds it's starts dropping back down?... I thought it was linear as in constantly increase until regen, this seemed to go up and down on the same stretch of road.

Opened bonnet, smelt a little but of oil but no smoke, my opinion is either the oil burnt off earlier or maybe for what ever reason the car did do a regen earlier today and those crazy exhaust temps caused the smoke.

Will order some stats, MPG is around 19MPG.

The values are calculated but there is a DPF pressure sensor and that's an input to the calculation. The pressure signal varies depending on engine load and exhaust volume. The design DPF load is over 100g. I have 172,000 miles on my X5 with that 67g of soot. No leaks, still gets 30+ mpg calculated Go out and drive your X5 for about an hour at normal operating engine temperature (>75C, IIRC) above 40 mph. The longer and faster the better. Order a regeneration if you like.

Yeah, over 600F at the turbo outlet should be sufficient to get the DPF temperature over 1000F during an actual regeneration. Much more frequent "passive" regeneration takes place at much lower temperatures.

Monitor the throttle position sensor (TPS) and engine coolant temperature. The TPS usually stays open at 94% during normal operation and may open to 99% or shut slightly under some extremely brief, transitory engine operating conditions. During regeneration, it will vary from around 10% to about 30% but will open up to any value up to 94% depending on some transient conditions. Coolant temperature should increase to the low to mid-90F ranges.

Thanks for the explanation, it's good to know about the TPS sensor. I'm just about to go and get my EGR Thermostat from BMW and install it later. I'll then monitor

Coolant temp
Exhaust temp
Throttle position sensor

And back out every now and again to view the DPF soot and Ash values.

It will be good to see a regeneration but also scary because that smoke I seen before was pretty scary and I hope not to see that again lol but as I tested yesterday, a few WOT pulls and 10 mins of 300/350, exhaust temps resulted in no smoke so if I do see 600 I might pull over to see if there's any crazy smoking and if all looks well ill drive to Blackpool which is a good 2 and a half to 3 hour drive and hopefully the soot will be down and the ridiculous 1000 backpressure reading will be back to normal.. Still concerns me with that backpressure, at what point does the backpressure strain the turbo seals/rear main etc?

In what unit is "1000"? If the DPF were plugged or back pressure were " too high", you'd be experiencing defueling and a great reduction in power. That and there's too many variables to properly understand that number in isolation. Was "1000" under load? How much load? Throttle position relative to that load? Those factors allow you to then extrapolate the HP that uptake should support. I'd expect 15 or so psi of backpressure under some conditions.

What "exhaust" temperature are you reading? How long were you holding the WOT? 600F pre-turbo is absolutely nothing to worry about. Under load, that value almost doubles. 600F post-turbo under moderate load is absolutely expected. Pre-turbo is over 1000F in that case. Pre-DPF temperature is around 400F at idle but easily tips over 600F under that load. It's probably over 800F inside the DPF in that case.

Here's some of my data.

Moderate acceleration, about 10 minutes of operation:
Attachment 82401

Start of WOT pull to 90mph after about 40 minutes of driving. Throttle rolled in to WOT:
Attachment 82402

Time 2, ~5 seconds from start:
Attachment 82403

Time 3, ~3 seconds from last:
Attachment 82404

Conclusion of pull, ~4 seconds from last:
Attachment 82405

At home, about 10 minute cool down:
Attachment 82406


Just drive it.

Also, I looked at my replaced BMW (Pierburg) OE throttle body and my currently installed Pierburg OEM throttle body and they actually both have springs.

Hi mate,

The screenshots are great and I can see that you use some other ones that I don't. So, the backpressure reading I'm getting hPa is actually at idle! Now I'm a tad skeptical of Carlys reading so tomorrow, just to confirm I'm going to take that same reading but with ISTA+

Oh and I was working in degrees Celsius so when the exhaust temp was hitting 600 that would be 1112 Degrees Fahrenheit. The good news is though that I had no smoke! I was very happy about that. I'm going to get the car aligned tomorrow and I'll go back on the motorway and get some more more data tomorrow and try to use the same parameters as you

Also in regards to the backpressure symptoms so far I'm getting 18MPG (UK) around town and I got 39MPG on the motorway but I really need to do a longer run because the MPG hadn't settled out, I went from 44MPG down to 39MPG with cruise control set to 60MPH

EGR thermostat couldn't be replaced either, I didn't think to order the bloody O-Ring, most times I order they add these into the order. Luckily I think the hot weather helped to get to the 90+ degrees Celsius coolant temp and later that evening it went back to struggling to get upto temp again.

I use Carly also with their Gen 2 adapter so you should definitely be able to find the exact same live data parameters. I was only guessing at the precise parameters you were monitoring and with what app or program. Not sure why mine are in F and psi unless there is a setting for that in the app.

Are those MPG values instantaneous? Sounds like it. They shouldn't be so volatile otherwise. 18 MPG Imp is probably okay for real town driving. For me in mixed driving, 30 MPG Imp is easy to attain. 36 MPG Imp would be great and I'm often in that range. 44 MPG Imp is not realistic at all, unfortunately. Fill up, reset the trip odometer or mark the odometer value, run half a tank or more, fill up preferably at the same station/pump, and then calculate your consumption. I've done that for every tank so I can evaluate operation and condition over the eight years.

I don't know what engine is in your 30d, though. What year is it?

Omd, it smoked again today! I took it on a 20 min motorway run and the exhaust went to 600ish for a while and when I got to my dads I checked and absolutely nothing... Went home on the motorway so same again 20mins on motorway exhaust temps not so high this time 350/450 and no smoke so great.

Took it out today on a very short town run and after 10 mins it was smoking lightly again.. I just don't get it. The only difference between last night's motorway run and the other two occasions it smoked was that I was out in the afternoon while temps are crazy high and the smoking occurred around town. But, if my exhaust can hit 600 for a sustained amount of time I can't see why my shorter journeys could be worse.

I've ordered an endoscope with the hopes that next time it smokes I'll put the camera straight under the valve cover air filter section and look straight at the exhaust manifold and see what exactly is smoking.

Regeneration will cause the entire engine, the entire exhaust to be hotter. Exhaust temperatures vary wildly on diesel engines because they operate over a wide range of air to fuel ratios which is dependent on the fueling rate which is dependent on engine load, ambient temperature, temperature of the air charge, air charge flow rate, boost pressure, and on and on . . . I don't know why your temperatures are varying but I think it has nothing to do with your DPF. You know you can monitor regeneration status? 0.00 for no regeneration ordered; 1.00 for regeneration requested. You can also look to see what the mileage was at the last five successful regenerations, average miles between successful regenerations, average fuel consumed between successful regenerations, and more. I routinely monitor these values to make sure they're happening regularly, especially since I have both the 452A and 4D4A advisory DPF replacement DTCs.

I got the depstech endoscope today from Amazon and from what I could see the exhaust manifold seems go be leaking quite bad from one area and there's many more sooty marks around the rest. However, I'm really confused as to why the smoke occurs only sometimes, after my motorway run, no smoke, back on the motorway and checked, nothing. However, on my small town runs it smokes, if anything I was actually expecting maybe the valve cover to have a hairline crack and now and again the oil seeps onto the exhaust manifold.

Here's a video of the endoscope,


4:57 shows headgasket, looks fine.
7:15 valve cover at the back left going around to exhaust manifold looks dry
8:40 soot around manifold

https://youtu.be/RXLfDiGnvtk