My AC was working as of a month ago. Then one day I noticed that it would only push cold air when I would accelerate. Normal driving or at idle it is warm air. I had a service shop check for leaks. No leaks and had 2.4lbs of R134. They said that there is a blockage somewhere and would be expensive and take at least 2 days to figure out where. Wanted to check if anyone else ever had same issue before I spend alot of $ having someone guess.

Thanks!!!

Sounds like the tempature door is closing or opening for heat due to the lack of vacum to operate it right. Dont know if your vacum pump is working right or if the vacum controler is malfuncationing not real familar with the diesel setup.:)

Good luck and please lets us know what you find out