LS1 question (not Z related)

[alsil]

So I have an LS1 in my '02 Silverado (5.3L) - and I am constantly filling the overflow bottle. On these trucks, the overflow bottle is where the radiator cap is.

 

So I try to find the leak, and sometimes I find a puddle under the truck directly under the oil pan. I figure it's dribbling down the outside of the block to the lowest point - the oil plug. but I can NEVER find any liquid on the motor. Even if the puddle is sitting there right after I stop the truck. it's dripping off the bottom of the oil pan, and that's as far up the block I can find the leak.

 

Now the frustrating part is that it doesn't do it all the time. In fact I drove from San Jose to home (Vancouver, WA) and didnt' lose a drop.

 

These are my ideas -

 

- The water pump is going, and it's escaping through the vent hole. I can't FIND the vent hole, I'm guessing it's under the snout of the pulley.

 

- A freeze plug is leaking? Does that even happen on LS motors?

 

- A hose is leaking, although I can't find a single drop of moisture on the hoses.

 

I helped a friend with his V6 truck a couple of months ago with a water pump that went bad, but my truck isn't acting the same. This would be a lot easier is the motor wasn't covered in tons of wires, covers, etc......

 

HELP! I have built tons of cars and don't have an issue for fixing anything - as long as I can find the problem!

[gvincent]

My 2000 5.3 Silverado Ext Cab Z71 4 X 4 does the same thing, It does leak/seep out the water pump vent hole just enough to loose enough coolant to make the low coolant light come on about once every month and a half, I has been doing this now for over 45K miles, I have 138K on it now and this was first brought to my attention a little over 2 years ago that I should replace the water pump, I haven't yet but plan to do so when it gets warmer outside in a couple of months, I figure I put it off long enough. I probably have gone through 3/4 of a gallon during the 2 years, I still have probably a little less than a 1/4 gallon left and the light came on again today so I will add some tonight. I was told that this was very common by the dealer.

Greg

[alsil]

I put in a lot more than that. I have probably put in a couple of gallons in the last year. I wind up putting fluid in about once a week. I don't drive much, my commute is just 10 miles each way. I get gas like once a week or less usually.

 

If the water pump seeps normally, that's weird. looks like the hole is under the snout, which is a bad place since gravity will make it come out eventually, even if the bearing is ok.

 

I'm gonna have to give the dealer a call and see what I can do about this. I don't like the thought that I'm leaving puddles of antifreeze everywhere I go for cats and dogs to lick up and die. Not cool.