Engine: D5: D5 troubles.. any ideas?

[Thassos]

Its a long story.. some weeks ago had an engine service required message come up randomly, along with an anti skid service message that had also randomly been appearing and then clearing.. Had the codes read and got the following

6662, 6663 and 6665 (glow plugs 2,3,5 intermittent)
1890,1870,1880 (swirl actuator:- jammed, neg drift, faulty signal)
2810,28E0,28D0 (O2 sensor signal related)
135F (Maf sig too low)

I checked/replaced the lefhand 3 glowplugs (is no1 cylinder LHS or RHS?) and this improved start up and idling smoothness but the engine ran pretty jumpily at low revs, and seemed to be getting worse, especially from from cold, i also read somewhere that glowplugs are used in the DPF regen cycle, so perhaps this had been affecting regen (would you normally get an engine service msg if a glow plug was dud?)

Having many years ago checked the throttle body and found a massiv amount of crud in there, (around 80k) i pulled off the hoses around the throttle body and egr (car now at 145k miles) and quelle surprise.. take a look at the attached pics _1 thru 3 !!

I cleaned out all of the throttle body and port in egr (however im not sure if the exhaust cooler side might have junk in it, but didnt want to removed the whole assy at this point (can the front piece be disassembled from the cooler section leaving the cooler in situ to clean out, or is it necessary to extract the whole EGR to clean this side?) while i was there i took off the front plastic 'pierberg' piece (green arrow-3rd pic) to investigate whats in there , this has 2 fork type connections that i guess go to the motor that works the cam on the EGR valve (see pic below), measured what might be the coil resistance probing in the 2 holes and got a low ohm resistance that could be the motor 3 ohms? (2red arrows in last pic) , there is also a plunger (pot? or hall sensor?), which i guess monitors the position of the cam/valve, seems to be no connection from the fork pins to the connector pins on this piece so i can only assume theres some electronics potted within? or is it simply a pot and the 2 motor pins? (if so mines broken!) its a 6way connector only 4 pins fitted, on the loom side i see these colours

1= Yel
2= Grn White
3= Grn/White
6=Brown/Black (see 3rd picture below)

There is also an actuator below this that does something with the cooler side i think, looks like operated from a vac solenoid (which measures ok) on top of housing could this control coolant flow thru egr cooler? lots of guessing here as I have no info apart from dr haynes which is somewhat lacking on egr info..

The egr valve appears closed, not sure if it could be contributing to the car running very roughly and kangarooing when warming up from cold.


I did find an interesting (and very long) thread on what sounds very similar
https://www.volvoforums.org.uk/archi...x.php/t-230401

Anyway i took it for a run after the de coke (its a long story this one...) and initially it seemed better, however after 10-15miles the performance really dropped off and it would only produce 3psi boost max, (could this be limp home mode?? never had this before..) when i read the codes on my ELM bluetooth it reported some new codes

P0406 Exhaust gas recirculation (EGR) valve position sensor A - high input
P242F Diesel particulate filter (DPF) - blockage/ash accumulation

I put all the inlet pipework back together/airbox and tried to start (initially ticked over fine, but as i started moving off it was struggling, with some kangaroo ing in 1st gear on light throttle it seemed to be running better as it warmed up, but after some miles i re checked the fault codes and it was only showing P242F (DPF filter restriction ash) but the other faults to do with MAF, O2 sensor and EGR had disappeared, in this mode it ran but boost only got to 3psi and performance gone, at one point the MIL (engine?) yello symbol also came up on the dash although the anti skid message had gone, just the engine service message on the DIM (as usual), the engine did seem to be running hot in the exhaust area so i wonder if it was trying to regen, only did 5-10 miles and parked it up. Next day i added some Forte DPF cleaner to the fuel, and took it for a long drive, kept driving despite the engine only going to 3psi boost and after maybe 40miles, 90mins it started to pick up, with boost maybe 10-12psi, i also noticed as i drove with my foot off the accelerator sometimes it would show 0.5psi or 0.3psi instead of zero (is this a sign of regen activity of some sort?) its a pity you cant see when its trying to regen anyway after 2 hours i rechecked the ECU on an ELM327 + scanmaster and it came back with no codes at all, and I/M readiness all of those shown were pass/ok, so it would appear no fault codes or MIL (well at least the ones scanmaster can read). At one point the dash anti skid message reappeared (not sure if its connected to this problem) But the engine still isnt running as it used to i seem to recall boost was up to 30psi, and im also wondering if it could be the Turbo VNT sticking as there seems to be a lot about that on the forum, yesterday i had a look round the intercooler and noticed the bottom edge of it has some black oily deposits, plus some alu fins crumbling away on the bottom row so im now wondering if this could be leaking?

Anyway im very much in need of some help, before i loose the plot and sent it to the crusher! or webuy anycar ! I cant believe how its gone from ultra reliable to awful in the space of a few weeks ! so if you have had any similar experiences that you managed to fix it would be very helpful..or if you have vida and are in the kent / sussex area (thats hoping!)