Evening chaps, more questions Because I'm inept and to be honest pretty poor at following guides in most forms can someone give me some information about this: http://www.audi-sport.net/vb/a4-s4-forum-b5-chassis/107121-un-sticking-your-tdi-vnt-turbo-vanes.html I know a couple of chaps on here mentioned the EGR spray cleaner method in my previous thread and wondered if this was the same concept using a different method, it appears to be a common problem with my model of A4. The problem I have is I struggle to learn anything by reading a guide like this, more of a practical person but don't want to mess up my daily while learning!
The method is fine, but the oven cleaner bit is wrong. Use a decent egr cleaner, it only costs a fiver for a can, and isnt acid based like mr muscle. Like i said in previous posts, there are many many reasons why oven cleaner should not be used.
Yeah I read in that thread to be careful with it because it would damage the cold side of the turbo. I'd rather use an EGR cleaner in fairness, simply so if I make a mistake (expect to do something not quite right) it won't eat my turbo. Would I use EGR cleaner the sale way or can I simply spray it through the front of the turbo on the intake side with it running?
I did the mr muscle trick and worked a treat. had sticking VNT, would overboost straight away and then go into limp home mode. found the VNT arm barely moved by hand. took off EGR pipe, used a windscreen washer tube to feed down into the turbine housing and sprayed down oven cleaner. left for about 2 hours to work, the VNT arm felt freer immediately and then I kept working it back and forth until it moved freely over the full range.
What product would be better suited to the job, I think you mentioned an EGR spray in a previous thread. Anyone got a picture of what the VNT arm looks like, I'm baffled by that bit
Its the vanes that stick. They look like little pin ball table arms almost. They tend to get coke built up around them and the actuator finds it difficult to move them the full travel, sometimes they stick completely. Its down to that old problem of being driven too gently too often. Egr cleaner is best because it foams up on contact with the crud and tends to carry it away better. There are specific turbo cleaners out there. They are all petroleum based in some form or another as this is same for brass and ally. If you dont fancy using a cleaner, good method is to grab the actuator arm (attached to the turbo and a big dome like thing with a tube going into it) and give it a few wiggles in and out. After doing this take the car and drive it like you mean it, get on a straight safe bit of road (make sure car is warm, oil and water are topped up) and redline 1st through to 3rd for a few seconds each gear. This will heat the turbo nice and hot, enough to remove enough of the coke to free up movement of the vanes again. Wouldn't hurt to repeat the above steps again starting with moving the actuator its full travel. This method works fine. I thrash my 1z once a week briefly just to keep everything clean, after a week of traffic and startstops it really notices.
Its not actually that difficult to take the turbo off take it aaprt and clean it properly. We've done a fair few now advising the customer the result could go either way but so far all have been good. Obviously if there are other issues affecting it.....
Not really, most cleaners are spent on the fuel system at that point. Direct application is your only real option.
the active ingredient in mr.muscle (sodium hydroxide) is the same as that used in the 'proper' solution AFAIK, just a lot cheaper. It will corrode aluminium but I don't think there's much risk to the cold side. As Barny says though the way to do it is take it apart and clean it. On mine working the actuator arm did absolutely nothing before the cleaner, it wouldn't budge! after an hours soak it started to move and then I could work it free.
Yeah that makes sense, if I'm under the car what does the arm I'm meant to be trying to move look like, want to see if I can free it then Italian tune up before I start taking things off and potentially messing things up.
