My 04 overheats while pulling up a grade. I did the egr delete and replaced the oil cooler about 5000 miles ago and it has worked very well. Now it seems the fan is acting up as it is on all the time but it seems only about 40-50% even from start up but when going up a grade and the temp starts to rise the fan doesnt increase like it use to it just stays on a little and doesnt roar like before. Any thoughts?? I dont think it is head gaskets as when the dealer diagnosed the cooler i asked about the head gaskets and they said the checked out fine. I have got to figure this out.
Any suggestions wouls help.