Non belt squeal

Hi, engine developed a squeal from startup that sounded like loose belt. Replaced both auxiliary belts with no joy.
Removed both belts and still squealing.
Replaced timing belt and tensioner but still squealing.
Checked actuation of waste gate and appears fine
Tightened up all turbo hoses and noise went for a while.....

Tried tightening them again to make sure not worked loose but this squeal is back with a vengeance. It's there from startup and terms to get worse as revs increase whether under load or stationary.

Sticking head in engine bay it sounds more towards injection pump side but that could just be reflection of noise.

Any thoughts??

Use a long screwdriver as a stethescope
Have a look at the inlet manifold gasket as they leak causing squealing noise under load.
Def or Disco engine?

Defender engine.

Crawled underneath again this morning and not sure if related but a high pitch whine on start Bedford squeal comes in. The whine sounds bearing like and from underneath seems more in direction of power steering pump/alternator. This goes after a few revs, as though something getting lubricated and noise easing.

Tricky to look at manifolds as so cramped, but had a good fell around them to check for any small holes etc. In process gave turbo hoses a good shake and repositioned few jubilee clips on them. Squeal not as evident now.

Also, would the steering box emit a slight squeal on hard lock if fluids all topped up?

Seems like I may have three different sources of noise now. Each is is fairly distinct when happening and had it's own characteristics!

As its a defender engine I would say pas pump as they have a so called sealed for life front shaft support bearing that just doesnt last if off roaded, I know Im on my 3rd! but as you said you tried it with belts off.
Ypu can check bearing play, slacken pas belt and gently lever pulley side to side any more than a couple of mm and its on its way, ####ing dear as well.
Yes all pas makes a noise when on full lock as its the relief valve opening, never hold a pas on full lock for more than 30 seconds as the fluid can get real hot real quick.
Only way to really check man gaskets is to replace, cheap as chips and easy job

Will check the PAS pump then just for good measure though not the source of at least one noise as had belt off.

In France at the moment heading South so gaskets not so easy to get hold of. Might get some sent out in case.

Quick check, there is a dust cap behind the pulley on pas pump, should this be loose? Can't find a way to clip it on properly.

Sorry dont know, should know as Ive changed to many of them, think I remember some sort of plastic shield?

Yep, nothing shows obviously on parts diagram. Will check on another one and see.

More detail on the squeal:
Takes about 20 minutes from cold before it starts, and needs to be under load for it to start. It won't start of just left running whilst stationary.
Once going it will stay whilst stationary and can be made better/worse by blipping throttle through rev range.
Went over a train crossing a bit rough and it made the noise ease slightly for a short while.

I dont know why we didnt think of this before head gasket?
When its hot feel around the back of cylinder number 4 nearest the bulkhead.

Will have a check.
Yesterday squirted some foaming leak check onto manifold and looks like some air escaping there so that's next job, also a leak where pipe joins exhaust. Not sure how to seal that one, gun gum?

Looks like inlet and exhaust manifold are in one piece, is it easy enough to move turbo out the way and replace or are bolts likely to be seized?

Do I need some rtv/hylomar on gasket when changing it?

Cheers

Bolts come undone, only ones that can be arseholes are the one that are double nutted 17mm spanner size not sure why but they tend to jam up, the rest are easy enough.
I think once unbolted the whole lots move out of the way just enough to get gasket in and out, havent done one for a year or so now, dont try and unbolt the turbo from the manifold.

Cheers Lynall that's great. No sealant needed either then?

Just need to get hold of a gasket whilst moving about in France then I'll give it a go.

Iirc I think I replaced a couple fo the studs due to corrosion so maybe worth while getting a couple, theres 2 x lengths again Iirc!