Recently, had the "Risk of filter clogging" warning, and a quick scan gave this detail,
So far so ordinary, although the car hasn't been used for short trips, 70mh for an hour solid is more normal. The dashboard warning went away after a few restarts.
Having a look at the live data, I'm intrigued by this, taken with the engine off, and not run for 3 days,
Which makes me think the pressure sensor is faulty. To me, there shouldn't be ANY "difference in pressure" with engine off, and as it's not-zero when off, it might be over-reading when running.
I just couldn't believe that the Differnetial pressure sensor would be allowed to read anything other than zero at engine off. I know some parts have a bit of tolerance in them, but I wasn't buying that.
So instead of buying that, I bought a used sensor off eBay. £12 of your finest pounds sir, and a used Sensata-brand sensor was on my doorstep at lunchtime. tbh I'd never heard of them either, but it does appear to be an OEM-quality part.
Hardest part of the job was opening and re-closing the sprung hose clamps, screwdriver to pop them open, a set of snips to close them.
On to the readings.
Engine off,
Idle,
I've no idea where the image went, it was 7-8 mBar.
3000ish rpm,
So, that's correct with engine off, approx 50% lower at idle, and 25% lower at 3000rpm. Odds are that's the root cause.
Resurrecting this, I was still getting the occasional P1490 error, almost to the yard at the same spot each time on the motorway. Very odd. The pressure was about 100mbar with throttle closed, at about 70mph.
I tried an aerosol-can cleaner, and it didn't do much of anything. So, bit the bullet, and took the DPF off to clean it.
SATURDAY
It didn't look massively sooty, but did look rather orange. This ties in with the EOLYS additive, which is largely iron-based, and doesn't combust during a regen. Over time, it's this deposit that can end the life of a DPF. In my view, it was already broekn, might as well try fixing it.
I used the Wynns' off-car cleaner, which comes as a 5 litre bottle for about £30. I used aroughly half of it, as I had opted to split the DPF to remove and clean the lower half only. It's not particualrly difficult to remove - couple of exhaust clamps, and the pressure sensor pipe. Removing these clamps, heat is your friend. Lots of heat.
I filled the lower cavity of the casing with bubblewrap to take up the space and save on wasted fluid, blocked the outlet of the dpf, and filled it to the brim with cleaner. Then left it alone for 24 hours.
SUNDAY
I got ready for the cleanout. Initially, removing the bung from the outlet resulted in, almost no fluid at all running out. Which was surprising.
I started using a pressure washer (carefully) to rinse the DPF from each end, but before long realised this was going to take a while, and switched to a garden hose, for volume rather than pressure. (and a lower leccy biill!). few minutes flushing back from the outlet, then switch and wash down into the matrix.
SUNDAY - 3 HOURS LATER
I should have worn waterproofs.
I was soaked, and finally nothing else was rinsing out of the filter. Every time I thought I had it, another channel would start flowing the reddish material out. What I took to doing was blocking the water flow out of the matrix to push a little more pressure through fewer channels. With hindsight, I could have used water plus an airline into the pressure sensor port. I'd also try and knock-up a proper bung with a hozelock fitting on it, instead of wrapping bubblewrap around the hose and shoving it into place.
After drying out with an airline (which is when I had the bright idea above), refitting and using Diagbox to tell the car it has a new filter, left it to idle for a while, then drove it fairly gently for a while to finish drying off.
TODAY
90 miles with no DPF warning. Which is about 70 miles more than it would manage previously. I'm going to run it another couple of days before I plug in Diagbox again and depress myself with whatever new problems lie in wait.
A Little over 200 miles later, and the results are in.
Idle pressure reduced,
Pressure at 3000rpm reduced,
And the car hasn't run a regen yet. Previously it was doing it every 100ish miles, the average counter seems to have reset to 500km when I coded the "new" DPF.
