f0ster

I have also seen it caused by the pipes taking the boost pressure to the ecu, they get oil in them and then the pressure has difficulty getting to its destination, when it does overcome the blockage it overshoots causing it to go in to limp home,

it will take a good four hours if you have not done one before, most of the time is taken getting at the belt, there are marks on the pulleys to line up, if you are not sure put your own marks on the pulleys and casing with tipex, and the golden rule, turn it over by hand before trying to start it, checking for tight spots at tdc, you will manage ok,

what big oil pipe, do you mean the one feeding oil to the turbo, if so it could be oil pressure to high, holding the hydraulic cam followers open slightly, which will be oil pressure relief valve sticking

I had a mk1 and it was single mass, I have done a bora that was dual mass and put a single mass in place, there was no noticeable difference in the driving of the car, a big difference in my pocket,

try backing off the tensioner a tiny amount, they try it again

does it feel ok when driving if you ease off the throttle and gently back on, as for the play you need to compare with another

it is slightly more difficult to do, a first time doing a belt kit will take a good four hours, the golden rule, if not sure about the timing marks put your own marks on the pulleys and casing with tipex, and "always" turn it over by hand checking for tight spots,

if there is play in a diff it is usually the thrust washers behind the sun gears/planet gears, the crown wheel & pinion do not take any harm other wise it would be screaming at you with gear noise, this low rumbling noise, how do you know it is from the diff, it could be a front wheel bearing, when a bearing is starting to go you can feel vibration from the strut if you hold the spring and spin the wheel as fast as possible

it might be the master cyl failing, when I have this asort of problem I back bleed the system, get a good oil squirty type oil can full of fluid, put on it the bleed nipple with hose and pump away till your harts content, this method is very good small volume systems as well like motor bikes,

you need to give it good hounding on a quiet road to burn off the oil, it will smoke a bit

all they will do is replace the center bearing assy complete with turbine/compressor and fit your housings if they are ok, they buy them in ready balanced and setup,

if it has a dmf fitted I would definitely replace it with a single mass, cheaper and you will not notice the difference, I fitted a standard flywheel assy in to a bora diesel, no difference noticeable, with some manufacturers you get a a transmission rattle at a certain revs but I have not noticed anything like this with the bora, it is the friction pad in the dmf that wears out allowing it to slap from one point to the other point

just make sure it is not the rocker cover gasket, start with the cheap stuff

turbos have a floating bush that is rotating independently of the shaft which spins at up to 120,000 rpm, this way the bush can turn at half the shaft speed and so reduce the surface speed, and also being fully bathed in oil eliminates metal to metal contact, ball bearings would struggle to cope with such high speeds, turbo technology is well tried and tested, I have seen turbos on trucks with 1000000 km on the clock,

I always use a good quality squirty type oil can with brake fluid in it and back bleed it from the bleed nipple,