Having a new issue and hoping someone here has some thoughts on cause.
Background on truck: '04 DII, 76K miles, Short block replaced at 50k by LRNA due to slipped liner, 180* soft spring thermostat, new expansion tank, newer radiator and hoses, fresh oil change from Mobil 1 0w-40 to Mobil 1 10w-40 High Mileage (badly needed as oil was dirty and old as shit).
Truck has been running great for a long time without any issues. Recently noticed a leak at the seam in the expansion tank so my mechanic replaced it. New one developed the same leak so that one was replaced. Ever since the first replacement, the truck has been running a bit hotter according to my ScanGuage. Normal temp range was 184-200* (exact same as my other '04 running the 180 T-stat). Now the temp range has shifted to 197-209*. So the range is about the same but it has shifted to higher temps. Seems to get hotter on hard acceleration too, maxing out at 209-211.
Also, I've got a ticking while in gear upon medium acceleration from 0-40/45ish mph. It sounds like that throaty diesel engine noise and sounds like it's coming from the passenger side. Doesn't happen while idling in neutral and with revving in neutral. Seems to go away with harder acceleration and faster speeds, but it could just be getting faster as well as being drowned out by normal engine noise.
Any thoughts on causes? Could my Thermostat be failing already? It's probably only a year old. Could the tick be an exhaust leak? My mechanic claims he couldn't find one and that he did a pressure test with no bad results. (clearly he will need to look deeper since nothing has changed since he worked on it)
Thanks
Background on truck: '04 DII, 76K miles, Short block replaced at 50k by LRNA due to slipped liner, 180* soft spring thermostat, new expansion tank, newer radiator and hoses, fresh oil change from Mobil 1 0w-40 to Mobil 1 10w-40 High Mileage (badly needed as oil was dirty and old as shit).
Truck has been running great for a long time without any issues. Recently noticed a leak at the seam in the expansion tank so my mechanic replaced it. New one developed the same leak so that one was replaced. Ever since the first replacement, the truck has been running a bit hotter according to my ScanGuage. Normal temp range was 184-200* (exact same as my other '04 running the 180 T-stat). Now the temp range has shifted to 197-209*. So the range is about the same but it has shifted to higher temps. Seems to get hotter on hard acceleration too, maxing out at 209-211.
Also, I've got a ticking while in gear upon medium acceleration from 0-40/45ish mph. It sounds like that throaty diesel engine noise and sounds like it's coming from the passenger side. Doesn't happen while idling in neutral and with revving in neutral. Seems to go away with harder acceleration and faster speeds, but it could just be getting faster as well as being drowned out by normal engine noise.
Any thoughts on causes? Could my Thermostat be failing already? It's probably only a year old. Could the tick be an exhaust leak? My mechanic claims he couldn't find one and that he did a pressure test with no bad results. (clearly he will need to look deeper since nothing has changed since he worked on it)
Thanks