stuck vnt mechanism

2001 freelander td4. 4x recon injectors, new fuel pump, synergy 2a and pierburg MAF, silicone boost hoses, disabled EGR, BMW crank case filter, new VNT filter.

It runs well enough with no warning lights, but seems a tad slow to pick up and is dead flat when pulling a trailer....really needs thrashed through the gears to get any speed, but once cruising seems ok. Everything else seems OK. I found a small vac leak due to a perished hose end, so repaired that and checked all the other hoses. The VNT appears to do nothing. I bypasses the solenoid valve and plugged the vac line directly onto the VNT actuator and nothing moved. Pulling or pushing on the linkage does nothing - it appears to be jammed.

From underneath, what way should it move? I assume it pulls downwards towards the ground?
What is its course of movement.... Looks like maybe 20mm or so max?
how much effort should it take to move it? I assume it should be free enough to be moved by hand? I made up a wee hook and tugging on it gives no movement.


So.....if it's jammed, is this something repairable? I assume with the turbo off, I will be able to dismantle enough to get at it, but will it require a full stripdown of the turbo?
If I make up a sturdier hook and give it a serious yank/dunt, will it free off or will I more likely break something internal or just bend the arm?

cheers.

also...maybe I shouldnt be trying to force it downwards...is it possible/likely for it to stick in the down position and should be shoved upwards to free it off?

nobody?

Variable Nozzle Turbocharger
The VNT system included with the TD4 ensures that additional power is available throughout the operating range of the engine. The system also minimises turbo lag for smooth performance...

Do you get a slight sweet smell out of the exhaust at tick over when hot ?

You say you've checked your vac hoses - did you check them for splits AND blockage or just splits ?

Check the routing ...



For info pipe 1 is solenoid vacuum to turbo, pipe 2 is vac supply to solenoid from the plastic reservoir at the side of the engine, pipe 3 is the solenoid vent to fresh air via the little filter. Check these for holes as they rub various engine parts...

never noticed any smells.
Yes, the hoses are all checked and free of leaks and blockages. There is a reasonable amount of vacuum pressure, which holds for a long time after the engine is off, so no leaks. Connecting the vacuum line from the reservoir directly to the vnt actuator does nothing.

On your photo, the vnt actuator linkage is held together with a circlip just visible to the left of the jubilee clip. I will try to remove this (access is a bitch) to see if the actuator works on its own and whether I can get the linkage to shift. After that, I reckon the turbo will have to come off to investigate further.

OK, The VNT mechanism on the turbo should be movable by hand or finger pressure ...

Are there no whistling noises when driving ?

You can try pushing it up with a screwdriver and get to move it a bit then use a ring spanner to pull it down...

a bit of up and down wiggling might work, but if it's seized, tis seized

It should be possible to test by using the live vac pipe and putting it directly on the pull down valve...

If the vehicle has been waded at all, it's possible that some muddy water has got into the actuator, as it's at 45 degrees and is open at the end ...