OK, full disclosure, straight off. I am working on a Mitsubishi Outlander 57 plate, however, it does have a BSY VW Engine so should be as similar beast to those with success on here, using Mr Muscle to help with overboost problem. From what I can see it seems close to a 1.9 Mark II with the EGR at the front with a the intercooler and engine gas diverter flap at the back of the engine with solid pipe running around to the EGR at the front.
Prior to Mr Muscle I changed the MAP sensor, which is in the nearside wheel arch and initially though it was better, but overboost and limp mode came back days after, so think I may have imagined it was better rather than it actually being better. So thought I would try the Mr Muscle Treatment.
Access is a pain and did try removing the EGR pipe for access, did manage to open it enough at the bottom to allow the pipe in, but with the limited entry space was unable to really tell if the pipe was right in the turbo. No difference other than skint knuckles.
Have tried again, this time I have opened the hot side of the turbo by tasking off the V Clamp between the turbo and Cat. On this car access is really tight and the bolt for the V-Clamp was fitted along the top of the manifold directly under the oil feed pipe for the turbo. I accidentally removed the bolt initially and found that I could not manage to get the clamp off or find the thread again after several hours of trying. Got a new one, tried again and totally knackered the clamp, that still stayed stuck. Ended up driving for a week with just corrosion holding the clamp on until I decided to just get a big jubilee clip and use it to secure the clamp and give up. Went under the car and the clamp was hanging loose. When splitting the parts, found the cat has a hanger using one bolt near the flexi pipe. In hindsight, probably removing this and giving it a shake would have loosened the clamp.
After splitting the pipes I had good access to the turbo, photo below and gave it a right good dose of Mr Muscle, even partially closing the opening back up to try and get as much in as possible. Actuator has always seemed to be free though and was moving OK as far as I can tell. followed the 2 hour process, actuating the actuator several times. Built back up and just as bad as It was.
Got a step by step guide from an Audi forum, can't find the link just now.
From that tried the car with and without the MAF plugged in, no performance difference either way, so changed it, no difference, still overboosting.
Have done some more checking and the car has a vacuum/solenoid block rather than a separate N75 so was limited to what i could test, however, I have taken the turbo vac line below the car and checked Vac effect on actuator. Not the most hygenic way as I was lacking a mighty vac, but sucking on the vac pipe moves the actuator no problem, using tongue on end of pipe while actuator under vacuum shows the actuator holding vac Ok.
I suspect that the n75 within the vacuum block is faulty, however, am at the limit of buying parts that turn out to be OK and as the block is about £200. Would be great if someone in the Motherwell, Carluke area south of Glasgow would let me try a working one to rule it out? worth a shot.
Otherwise, last ditch attempt may be this manual override mod from the MKIVS Golf forum. Which is the main reason for my post. As it looks like this in addition to Mr Muscle may be a longer term cure for overboost and help to keep them moving better and provide more force to move slightly sticky vanes. it basic takes a feed from your boosted intake side, via a regulator set to your max boost pressure and shunts a pressurised feed back to the vac line for the actuator. Which should help it kick though any stickiness and hopefully in my case do the regulation work of the internal n75 valve in the vacuum block.
Post is here https://uk-mkivs.net/index.php?showtopic=9860
Any thoughts as to whether this may not be a good idea?
