Engine/Transmission (1998.5 - 2002) Chasing down a coolant leak - please help!

[HeavyHauler]

Guys, I am leaking coolant and experiencing warmer operating temps especially when pulling grades with a load behind me. It hasn't gotten to the point of overheating yet, but I'm assuming the warmer temps are due to the low coolant level in the radiator. 155,000 mostly easy miles on the truck. I was leaking coolant earlier in the year, so I replaced the water pump in March, and that stopped the coolant loss until just recently.

I have been all around the engine with a light and am only seeing a wet spot on the front of the block just to the left of the A/C compressor bracket. The area under the water pump appears to be bone dry, but I guess it could be running down next to the gear housing and settling at the wet spot. A small amount puddles on the ground intermittently, but not all the time. I have checked the line below the exhaust manifold and everything looks dry there. Radiator and area surrounding also looks dry.

Could this new water pump have gone bad already? Are there any other possibilities for a leak that I'm not thinking of that would settle on this area of the engine block? I need to make an 1,800 mile run to pick up a car very soon but am afraid to head out like this.

Thanks for the help!

 

[B.G. Smith]

The engine oil cooler is mounted to the block behind the oil filter. Think it has two gaskets between it and block. bg

 

[AnOldBiker]

When my o6 was about 4 years old, I noticed a slow loss in my puck bottle over time and a wet spot under the truck. I was talking to the service manager at the local dealership to see how much it would cost to trouble shoot since I was tired of it. He opened my hood and on the passenger side, at the back of the engine is a small hose that is in a 90 degree bend, it's wrapped in a silver material and just below the bottom of the head. Not sure of the name or where it goes. He told me to tighten the screw clamps o each end. He was right. Tighten then and hasn't leaked since. The leak was slow and small but adds up over a short period of time.

 

[JR]

Check out your heat exchanger and more likely the coolant lines running to and from it. The return line from the heater core also is in that area. Also what about the connection at the lower radiator hose? All of this is more on the side of the block so if you can eliminate the above the water pump is about the only thing left.

 

[HeavyHauler]

I've ruled out the oil cooler. Everything looks fine around that area. Wherever the leak is coming from, it's on the front of the engine or the engine compartment. To give a better idea, I have drops of coolant on my sway bar and the aftermarket steering stabilizer that everyone was putting on these trucks about 10 years ago. I can't find coolant anywhere else other than the front of the engine block next to the A/C compressor bracket, and that has dripped on down to the front edge of the oil pan. It is a small leak, but enough to make me worry because of the warmer temps I'm seeing. The location of the drops is pointing to the water pump, but like I said, it's bone dry underneath it. Before I changed it, that area on top of the gear housing was wet from where the pump was leaking out the weep hole.

 

[gdcone]

I don't know if you have found this leak yet, but I had the same kind of slow leak . What I found was the lower radiator hose was rubbing (actually stabbing) on the inter-cooler hose clamp. The clamp had worn a small hole through the radiator hose and the leak was underneath the hose and not easily viewed from under the truck. I looked several times before I actually grabbed the radiator hose and forced it up off the clamp and saw the worn spot. I replaced the lower hose and spun the inter-cooler hose clamp just enough to miss the radiator hose and problem solved.

 

[SnoKing]

I don't know if you have found this leak yet, but I had the same kind of slow leak . What I found was the lower radiator hose was rubbing (actually stabbing) on the inter-cooler hose clamp. The clamp had worn a small hole through the radiator hose and the leak was underneath the hose and not easily viewed from under the truck. I looked several times before I actually grabbed the radiator hose and forced it up off the clamp and saw the worn spot. I replaced the lower hose and spun the inter-cooler hose clamp just enough to miss the radiator hose and problem solved.

The was a common problem years ago, with lots of warnings to change the factory location of that clamp on this and other sites. However my bad water pump put water in the same location as the OP!

SNOKING

 

[Bob4x4]

When my o6 was about 4 years old, I noticed a slow loss in my puck bottle over time and a wet spot under the truck. I was talking to the service manager at the local dealership to see how much it would cost to trouble shoot since I was tired of it. He opened my hood and on the passenger side, at the back of the engine is a small hose that is in a 90 degree bend, it's wrapped in a silver material and just below the bottom of the head. Not sure of the name or where it goes. He told me to tighten the screw clamps o each end. He was right. Tighten then and hasn't leaked since. The leak was slow and small but adds up over a short period of time.

That only applies to 06 and early 07 models

 

[klcammie]

Not sure where your leak may be other then water pump, but you mentioned warmer temps, I assume you mean coolant temp. If so be sure to check your radiator it might be plugged up with dirt/bugs. On my 01 I couldn't tell how dirty it was till removed, then it took 2 bottles of degrease to clean. Then my temps dropped to normal again.
Hope you find leak.

 

[kscheffler]

I chased a leak on the passanger front by the water pump and it was the head gasket in the foward corner on the passenger side. Not good; look hard around the head gasket. The block heat evaporates the water so hard to find. Hope that is not what your problem is. I would not think that a leaky head gasket would casue temperarure increases so it probably is not your problem.

 

[wlowe]

If it turns out to be the water pump get a cummins or Dodge pump. I used one of those cheap $30 pumps and it only lasted a few thousand miles before leaking again. I believe the cummins pump was about $160.