Strange Coolant Leak

[febtober]

OK, I 'll try to get right to it. I have a 2000 LS8.

Over the winter, I had a leak in the lower coolant tube, so I replaced that, along with the water pump, belt, and thermostat. On an unrelated note, I was having the no-heat issue, too, traced it out and repaired the Aux Coolant Pump. I now have a weird leak that may or may not be related.

I park and leave the car sit overnight, the next morning, there is a puddle on the floor roughly the size of my oil pan, and the bottom of the oil pan is damp, with drips of oil on each pan bolt head. I can feel up over the top of the oil pan and also feel wetness and even what feel like pools of coolant. Yes, it is cooolant, not oil, that is dripping.

If I dry off the bottom of the oil pan and up over the top of it all around, it is wet the next day.

If I drive it a bit running errands, etc, there are no puddles if I stop for a bit. It just starts leaking overnight.

There is no spraying or leaking when parked at idle, and I have no overheating issues. If I were to guess, I would say there is an actual drip from the pan to the floor about once 2-3 minutes. Again, the entire pan is wet, the coolant accumulates at the pan bolts, then drips.

At first, I figured it had to be something on the top of the motor that would leak evenly on each side. I thought it was the fill cap on the engine; it was a tad loose and leaking, but not after I tightened it up. Now I can't see anything leaking on the top side of the motor, all of the wetness is coming from the lower half, and it seems to be evenly distributed between pass and driver sides.

It SEEMS as though a seal is leaking when the car is cold. When it heats up, things expand and seal it off. Then it cools down, metals contract, and the leak resumes. BUT, it only seems to leak a set amount. For example, the size of the puddle is not much bigger if I leave it for 2 weeks than if I leave it for 2 days.

Sorry for dragging on, but I was trying to be as thorough as possible. Plus, it is nice reading other people's problems so we don't think we are alone

Any thoughts would be greatly appreciated!

Thanks,
Febtober

 

[febtober]

Upon closer review last night, it might could be a bad water pump or a bad install on the pump. It SEEMS that there is more dampness towards the front, the pool I mentioned is at the front, behind the oil filter, pretty much under the water pump. The dampness also seems to be at below the pump. Again, this is all just damp, not streaming or spraying liquid.

Sound reasonable? Hoping for some feedback before I pull the pump off again.

Thanks,
Febtober

 

[HALFGIG]

When I replaced my water pump I had a leak just like yours. The new water pump was just a hair different. When I took off the old on there was a plate that was between the pump and the engine. That plate did not seal. The pump came with a gasket so I took the plate out and used just the gasket with some Permatex on it for sealing. Works like a charm.

The leak was hard to detect, I feel your pain.

There is also an o-ring on there as I recall. Don't over torque the pump.

Below is what the manual says for my 2001 V8 model

NOTE: Lubricate the water pump O-ring using the appropriate coolant.

Install a new gasket and the water pump, and tighten the bolts in two stages:
Stage 1: Tighten to 8 Nm (71 lb-in).
Stage 2: Tighten an additional 90 degrees.
Install and tighten the water pump pulley in two stages:
Stage 1: Tighten to 10 Nm (89 lb-in).
Stage 2: Tighten an additional 45 degrees