Thanks both. I drafted out a reply to Halftone before, but it disappeared into the ether.
The flaps are Ďparkedí with the ball joints at 9:00 as viewed from in front of the car. I tried moving the bar manually but couldnít shift it. Maybe this is just because it needs twisting on its spindle to move, but it could be that it is locked off somehow. I was thinking though; would someone go to the bother of locking the flaps but leave the EGR valve alone? Mine had the original fully open gasket. It wasnít too gunked up when I cleaned it; the shaft is moving and the solenoid can be actuated from Multiecuscan. I will give the beer can experiment a try at some time though.
DG, where are those turbo pitch hoses? Could a leak from these be responsible for all the soot under the throttle body (see photo)?
I fitted the new upper inlet hose last night but havenít had a chance to see whether it has made a difference. I will report back.
As I mentioned in the original post, Iím new to diesels (other than the odd hire van) and donít really know how a good running JTDm should feel. Mine idles and cruises fine, revs strongly over 2000rpm, is economical and shows no error codes. Against that is the smoke at start-up (I suspect one cylinder isnít firing immediately), the soot under hard acceleration and around the engine and the roughness accelerating under 2000RPM. The turbo whistles but, again, I donít know whether excessively. What might be useful is if there is a forum member in the Southend area who knows the engine and can have a look and listen for me.
The throttle body isn't. Diesels don't normally have them. It's an air-shut off valve to ensure the engine stops without running-on, when ignition is turned off.
It's pretty normal for the whole inlet side to accumulate oil (mist from the turbo) plus soot from the EGR. The valve body and interior of the inlet manifold can get strangled with an accumulation of the oily-sooty gunge many mm thick, and any slight leak from the boost pipe connections will be oily as well. As the turbo bearing and seals age and wear, the oil mist increases. However some is normal, and there's no knowing how long it's taken to accumulate, so it's hard to say how much should worry you. Clean it off with brake cleaner, and keep an eye on it. Unless you have other reasons to suspect the turbo is on the way out, don't worry.
The soot is from the exhaust fed into the inlet by the EGR - which is another good reason to blank the EGR off, aside from unreliability of the valve itself. It's a good idea to clean all the crap out of the inlet manifold, when deleting flaps and blanking the EGR. But since your flaps seem to be disabled and the throat of the valve looks pretty clear of gum from what little I can see, I think you can forget about that. You'd get a better idea after removing the valve throat containing the flap (3 screws, ISTR), then you can shine a torch and see inside the manifold. It only really matters to the extent that airflow is obstructed.
It's not daft to disable the flaps, as has been done here, as long as the spindle seals aren't leaking boost. You'd likely seen more general sooty oiliness around them if they are leaking. If they're dry, it's another thing you don't need to touch. If they do leak, clean with brake cleaner and smother with silicone sealant as a repair until you take the manifold off and remove, and seal them properly with plugs or weld.
Maybe one of the glowplugs is on its way out. That might explain the slight reluctance on cyl#1. Is the smoke white? (unburned diesel). There are various ways to test, but just removing it (9mm deep socket is best) and putting across a battery should give a bright red tip within 2-3sec. A set of 4 Bosch can be had for ~£28 on eBay. Or you might need the injector testing.
Turbo whistle: Although it can indicate a damaged turbine or bearing wear, some cars just seem to do it, for years and years. It's not necessarily a fault until it resembles a police siren, by which time engine oil will be pretty obvious in the exhaust, and smoke. Keep an eye on engine oil level. It should use virtually none.
dg is spot on, that there is just a bunch of things you need to work through, and once done it's a good, reliable engine. Doing the oil cooler dodged a major bullet. Swirls and EGR seem OK. Cam belt is another grenade, usually due to waterpump failure. Alfa's original recommendation of 72k or 6 years is obsolete, a lot didn't last that long. 5yr/60k is still pushing your luck, 4yr/48k is safer - but note it really is age OR miles. Anyhow, unless you know for sure when it was last done, please don't assume... it's a pretty easy job, if you have the tools, and timing lock kit (about £20 on eBay).
What year is your car? You said it's a CF4 but it has a CF3 manifold. That might point to earlier swirl flap failure which with the metal CF4 flaps often causes bent valves. A compression test would eliminate the rather horrid possibility that the car was given a new manifold but not the head repairs.