Originally Posted by streblo

^ agree, def sounds like something is blocking when you switch to heat......
spending the cash on the scope is easier than pulling the dash out to get at the heater core.......but.......if you use the scope to see that something is blocking it then you will probably have to pull the dash out to get at it anyways.......i think shops quote heater core replacement at 6-8 hours labour, so that puts it into perspective on how much work it is to get at it (And how expensive it could be to get a shop to do it).