It's almost impossible to understand what you're saying.
Let's try breaking it down into phrases and see if that helps
110bhp turbo trouble 1.9 tdi
So this is a TDI 110 motor, ASV or AHF? and what year? It can
help to narrow down problems areas.
there a problem on these engines
There's nothing like getting the audience on your side. And that is nothing like getting the audience on your side . . .
Turbo boosts too much
Do you have a boost gauge? If not how can you tell? Engine management light coming on at all?
cpu puts it in safe mode
I assume from this you are having problems with the car dropping into limp mode, but I have to guess. It would
help us a lot more if you'd describe what you are doing just before it goes into limp mode, i.e. what is triggering the limp mode.
u loose loads of power
That's what limp mode does.
You can spell "loose" but not "you"?
when u restart it it resets its fine.
Yes, that sounds like limp mode, as far as I can make out.
£400 for new turbo. any ideas anyone
Lots, but I'll try to confine myself to useful ones.
It would
help if we knew more about your car, what year it is, how many miles it's done, what modifications it has and what has been done to it recently (servicing and mods).
Like Sssstew says, sticking turbo vanes is one
problem that produces the symptoms you seem to be describing. This is caused by soot build-up on the exhaust turbine section, which has moveable vanes to control the turbine speed, spin it up at low revs and keep it from overspeeding at higher revs. If they stick at the low-rev position the turbo overboosts and triggers limp mode. Remedy is to clean the soot off.
1) Try getting the turbo hot to see if it will burn out the soot. Difficult if you're already getting limp mode. Need to load the turbo without revving the engine too much. A long steep hill, motorway or dual carriageway, is the best place to do this - start off at a low speed and keep in a high gear all the way up, going as fast as you can (paying due respect to safety and legality) without triggering limp mode. If you see sparks flying out of the exhaust this is a sign that the carbon is being burned off and spat out - several posters here have reported this in the past
2) There are some chemical treatments that you can squirt into the inlet trunk that claim to clean the soot off. Others on here have reported using them with some success.
3) You can take the turbo off, disassemble it and clean it yourself. Not too difficult in the spanner department - remember to cap the oil feed. Some helpful pictures here
http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/vnt15-turbo.html
Soot build up is accelerated by lots of low speed driving, slow commuting, shopping trips etc. The turbo never gets hot enough to burn off the soot so it builds up.
Higher miileage engines sometimes have trouble with sticking EGR valves, which cause similar symptoms. Check and clean the EGR, replace it or block it off.
Text-speak, lack of puncutation and grammar all make it harder to work out your meaning, as well as indicating your disrespect for the people trying to read it.
You're saying "I can't be bothered to spell things out, put in dots and commas or put my words in any sort of order. Do it yourself". So why should I bother to answer you?