A little cough...

VGT clean.

i got under the car and managed to drown the VGT accuator with CRC. It didn't seem sticky before I lubed it. I then managed to get my hand to the mechanism, which seems to have a small longer rod to enable manual movement??!! I could move it and it seemed smooth enough but the spring is really strong and was really at the limit of using my finger to work the vane.
Is it meant to be so strong?

The first drive seemed better, but after 15 mins it was the same.

Regarding the boost sensor, how do I tell if it's playing up?

I've cleaned to little sponge by flicking it, wasn't really dirty.

Does anyone know if I can put pressurized air down any of this vacuum system to clean it? Are the little right angle connections on the back of the inlet manifold, the feeds for this system? Do they just venturi into the manifold??

Any thoughts??? anyone had this apart?

thanks in advance. :depressed:

It's really hard to check with finger pressure as the vacuum actuator acts as a strong spring that masks how free the VGT mechanism is or isn't. The only reliable way to check the VGT vanes aren't sticking is to test with a Mityvac (or cheap Chinese clone - ~15GBP on eBay) vacuum pump, connected to the actuator with a bit of hose. The actuator should move proportionately right back to the stop as you increase vacuum from 0-approx 18cm Hg (full range of the actuator is specced at 0-20cm Hg). This is about 2cm total movement at the lever end, not 1cm as eLearn states. If it jams and stops part way, or the movement isn't linear, the variable vane is sticking due to carbon and/or rust. Aerosol cleaners can deal with carbon, but not rust. It often is rust, just a tiny bit on the cast iron surface jams the moving vanes. Or, more rarely, at very high mileages you lose movement in wear to the VGT mechanism itself, within the turbo.

I think it's worth taking the turbo off and doing the job properly. It's then just 4 bolts to get inside the exhaust side of the turbo and clean it up and check for wear. It's also a good opportunity to check the general condition of the turbo impellers, seals and bearings. You have to detach the front cat from the turbo to use an aerosol and that is the hardest bit of removal anyway, thanks to the ferocious V-band clamp. If rust is the cause, you won't find out until you find it still sticks, so have to do it all again.

EDIT: and the vacuum used is created by the vacuum pump on the gearbox end of the cylinder head - the round, silver can thing, it's driven by exhaust cam rotation. It seldom goes wrong. What does very commonly go wrong is the vacuum pipe between the vacuum solenoid and the turbo vacuum actuator splits or develops tiny holes, that leads to lack of or erratic boost at low revs. Definitely the first thing to check, and it's a cheap and easy fix to replace (3mm ID silicone tube).

OK, so I couldn't wait till the weekend so went out to the shed after dinner and fitted the EGR simulator and full blanking plate.

After hooking up the EGR Simulator I checked the ECU for errors of which there were two: One being that the MAF sensor had been disconnected and the other that the EGR had been disconnected. This was because the instructions say to turn on the ignition with the EGR disconnected and check the voltage with a volt meter on the two connecting pins on the EGR harness to make sure they are the right way round. It just so happened that I had the MAF sensor disconnected at that time also. So I used MultiECUscan to reset the errors.

Took the car for a run for about 45 mins, all different speeds and different loads. The good news is that there is now NO STUTTER. Zippo, Zilch, Nada. Drives like a dream.:thumbup: There is also no check engine light either. So I will continue to drive the car for another week then report back. Fingers crossed because so far so good.

Also, the wiring for the simulator comes in a proper harness now which is so much better than the photos on the Ebay advert.

The car still feels like that it has a "Power Band" when the revs hit 2.5 to 3k, but maybe they all feel like that? I don't know but it does feel good. Will report back in a week unless something happens before then.