Hi I have a modified sti type r ver 4.

I have a hesitation problem about 3500rpm espically on 1.5 boost.
When taking to my local turbo garage they located traces of oil in the pipes and have no idea where this is coming from ..

does anyone know what this could be and is it causing the hesitation.
Any help would really help and would be greatly appreciated.

if the car has been overfilled with oil then that can cause it to get in the boost pipework/solenoid etc.

For your hesitation it could well be down to the sparks from the plugs being blown out by the boost levels you are running. Would check the ignition components to try to erradicate that.

There will always be small traces of oil in a turbo cars pipe work. Its mostly made up of oil vapours that are being re-routed from the breather pipes, back into the induction system. These vaopurs are poisionous, so car manufacturers don't vent them to the atmosphere. Thats why people get oil catch tanks, to catch the excess vapours away from the induction.
Either the mechanic didn't know that, or there is more than what you would get through normal circulation.

The mechanic is saying that there shouldnt be oil between the boost valve and turbo. Is this right or are they trying to load me with a big bill for no reason?

I was under the impression that it would be throughout the boost system. Where there is air, there will be vapours. I could be corrected, if this guy is a turbo mechanic, he should know his stuff.

If you are concerned about a big bill. Get it away from that garage, fit an oil catch tank (around 45 quid), clean the boost pipes, oil change if you like (to elimate possible overfilling) and run it about for a month or so. You should see the catch tank has a fair amount of residue in there, that would normally be collected in the pipes.

The hesitation could be comething else.