I had my engine rebuild after turbo blown and the engine picked up an oil. So i took it to a garage and they told me that i need new engine and turbo (pretty much everything) so they offered me to go for an engine rebuild in order to save time and hustle registering another engine. Fair enough! After i got the van back they said that because the turbo fault my exhaust has been blocked with oil and its going to smoke for a while until clears. The engine works fine and sounds good but when it gets warm most times after I've been siting in a traffic for a while it feels like something is blocked and there is no power on start!? Than it goes back to normal again at some point. I was wondering could be that the intercooler blocked or what could be that is causing this problem?? Any help would be much appreciated!!