Have a coolant leak which is way more than a drip, but less than massive. Here goes -Leak coming from drivers side front of engine. Thought initially to be a freeze plug, but its not. Checked all hose - good. All clamps tight. Thermostat and housing good. Here's the odd item; it will drain the resvoir then stop. Resvoir is good and hoses are good, besides the resvoir is on the passenger side. Water pump is only a couple years old and when I replaced it i replaced the small bypass hose and the metal pipe in the front on the water pump; therefore all of that is new, not thats its impossible for the small bypass hose to leak, but obviously cannot see through the a/c bracket. I do not see any coolant on top of the engine, just the liquid dripping off after the engine is shut off. Only other thing I can think of is the weep hole on the water pump. Any one have a similar issue?

 

Check the water pump weep hole closely - even though the water pump isn't too old, that could be where your leak is. My water pump is leaking slightly, even though its only a few years old. Also, have you checked the radiator? Those are famous for leaking where the plastic tanks and the aluminum core meet. If you find the radiator is leaking, look into replacing it with an all-aluminum radiator (such as the CSF 2969, typically available on eBay), as they are not much more expensive than a factory replacement radiator.


Best way to check it is to pressurize the cooling system with a small pressure pump (can likely rent/borrow one from a parts store) and look for leaks like you mentioned.


Also, be sure to check your oil to ensure coolant is not leaking into your motor. Same for the transmission oil - check that too, just to be safe - sometimes the radiator cooling tube for the transmission can rupture, causing coolant to leak into the transmission and ruin it.

 

I had a similar symptom picture a while back and couldn't for the life of me find the leak. I wanted to know with certainty where the coolant was coming from before I got into it, but that just wasn't going to happen so I bought a bunch of parts and tore into it. It turned out that the upper radiator hose was weeping at the thermostat housing, but it was at a point that was hidden until I disassembled things.

Things are so densely packed around the top-front of the engine that sometimes you just have to take the obstructions out of the way to find the leak.

 

I'll also recommend to check closely around that upper rad house to thermostat housing connection as well as the thermostat housing gasket....when I first bought my truck I had a steady little stream of coolant coming down the front of my engine and I couldn't for the life of me figure out where the hell that leak was coming from. I eventually took the same route as unregistereduser and just started taking things off one night. Turns out the coolant was seeping out of the gasket at a point where I couldn't see it because the view was blocked by the alternator and accessory bracket. That gasket is a weak point in the cooling system.

 

will do. thanks for the suggestions. I will report back when I find it.

 

You can buy this dye at the auto parts store that you put into the radiator and use a small black light that comes with the dye to help find out where the leak is coming from. It is a lot easier than just throwing parts at it.

Coolant Leak Detector Dye

UV Light & Goggles You can play CSI too

 

Have the same problem on my '95 D2500 w/V10.

Same symptoms as you describe, mine turned out to be the radiator, driver side, where the plastic tank and core meet.

At first, it only leaked when I shut it off, then it got a bit worse, that's when the fan/wind from driving blew it against the side of the block.

The dye sounds like the way to go, should be able to pinpoint it right away.

 

List of suspects not easily seen

-upper rad hose or t-stat housing (you can see this partially looking from the pass side)
-w/pump bypass hose (Hard to see , maybe with small mirror)
-w/pump
-timing chain cover gasket (look up from underneath for these last 2)

 

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.