I did a search in the threads but couldn’t find any with the problem in my truck. The coolant started leaking about 2 weeks ago, pure coolant yellow greenish color. Checked every hose attached to the radiator and the radiator itself and all were intact. Finally while it was leaking, I was Abe to trace it right behind the lower pulley. So I thought it’s the water pump. Took it to mechanic and they said the tensioner pulley assembly was stuck that eventually put the water pump out. Replaced water pump, tensioner assembly and upper radiator hose. Truck was fine for a week and now I have the same leak from the same spot. The leak is intermittent, which driving me crazy. The only pattern I observed is the leak happens first thing in the morning after I drive the truck for less than 5 miles. Any help is greatly appreciate it.

 

So only when the engine is cold?

 

That’s what it looks like. First noticed it on a Sunday the truck was parked all day, drove to the corner store less than two miles and when got out of the store I noticed the green coolant dripping, brought the truck back from repair last Friday so this morning I checked coolant level and the reservoir was empty, checked the radiator and it needed coolant. Drove to advance auto part which is only 4 miles from my place, and when I parked the truck, I noticed the coolant is dripping. Then, drove for about 15 miles and back to my house and was not leaking. Parked the truck and cooled Off before I opened the radiator lid. I added half a gallon of coolant to top it off. Drove to work in the afternoon and back to home which is about 30 miles round trip and no leak.

 

I wonder if you have pitting on the timing cover or it's tweaked a little. Could be a bad water pump out of the box

 

Take it back to whomever it was you paid to do the repairs........

 

So had the same issue today, but this time it started leaking while engine was cold and hot. First drive in the morning while engine was cold, drove About 25 minutes and parked, coolant started leaking, then drove to another place about 10 minutes and leaked again. Drove for about 30 minutes and it didn’t this time. Drove again and parked and again it didn’t leak. So I decided to take it back to the shop. While parked there, started leaking again. The difference this time around, I started hearing a hissing noise. Truck is in the shop and I will post the findings.

Thank you Moparfanatic21 and HeyYou, and everyone else for the responses and suggestions.

 

Let us know what the problem was, as I'm a curious guy

 

Bad out of the box new water pump, replaced with a new one and only drove around like 30+ miles and so far so good. I will be going back to work next week with daily driving and will see how it holds up.

 

That's what I was betting on, glad it's fixed!!

 

for the rest of the 2nd Gen Ram 1500 5.9 v8 community, here is a recap of the problem and
the fix:

Indication and warning:
- started coolant burnt smell.
- week later, observed clear coolant dripping behind lower pulley.
- amount of leak starts small then it increases by time
- after parking and engine is hot, coolant leaks start and followed by a hissing noise in front of the water pump

The problem (at least in my case)
- tensioner assembly was stuck which led to over burden the water pump and eventually caused the water pump to go out.

After replacing the tensioner and the water pump and the same problem exist, it was a bad out of the box water pump. Replaced water pump under warranty.

Recommendation:
Since you’re replacing the water pump, replace upper radiator hose and thermostat as well. If the water pump is all what is bad, it worth replacing the tensioner assembly as well.

Thank you for everyone with their advice, and have a GREAT AND HAPPY 4th of July.