cooling system

I have a 2000 chevy silverado with a 4.3 and 60k miles on it. In the last three months I have had to put in about a gallon and a half of coolant in my truck( this is the first time in five years that I have had to put any in it). I have no visible leaks coming out of the truck and when I contacted my dealer about blown head gasket, they told me that if it has never gotten hot that it should not be a blown head gasket. I checked the nipple on the intake manifold that they said may have gone out and drained the radiator and put in new coolant. Now I can hear a gurgle or water swooshing that sounds like it is coming from inside the dash. I have been told that it could be the AC not draining properly. The service department told me that since the truck was not missing and did not run funny that I probably shouldn't worry and that it wasn't uncommon to have to put a little coolant in when the oil is changed. I have changed the oil and no coolant was in the oil. any ideas???? I don't really won't to take it to a shop if nothing is wrong with it.

Your heater core is not leaking into the cab, is it?

Mine leaks a very small amount as well and I usually have to add about a half gallon every 2 months or so. Mine leaks at the water pump only when driving.

no it is not leaking into the cab and you cannot smell coolant in the cab or around the motor

Mine started using coolant, but it was a cracked head gasket and it was going inside the engine. I didnt notice it for about 4K miles, but when I did, man it was horrible!! If you see any unusual looking deposits in your oil when you change it, be very careful. Mine blew up shortly after this happened.

no it is not leaking into the cab and you cannot smell coolant in the cab or around the motor

Everything I have ever seen where they mate aluminum heads to a cast iron block blows head gaskets/cracks heads like a sonofabitch. Sucks they switched

I probably shouldn't worry and that it wasn't uncommon to have to put a little coolant in when the oil is changed. I have changed the oil and no coolant was in the oil. any ideas???? I don't really won't to take it to a shop if nothing is wrong with it.

Hard to say where it's going without seeing the truck. However, losing one and a half gallons is NOT normal, and it is also NOT normal to have to add coolant every time the oil is changed. It is going somewhere that it isn't supposed to. Sometimes things need to reach a certain point in the warm up or cool down stages before they will leak, sometimes making diagnosis difficult. To be on the safe side, keep an eye on the oil condition until you get it figured out.

My guess on the dash gurgle if it only started after the drain and refill is air in the cooling system trying to circulate through the heater core.

[QUOTE=alnheath]I have a 2000 chevy silverado with a 4.3 and 60k miles on it. In the last three months I have had to put in about a gallon and a half of coolant in my truck( this is the first time in five years that I have had to put any in it).

I have a similar problem that started after my catalytic converters plugged up (5.3 litre engine). This was at 104,000 miles and about this time last year. I was away on vacation and probably put about 1500 miles on my truck on the way back home before I could take care of it. I now have 135,000 miles and I've had to add water/coolant 3 times to the tune of about 1 1/2 gallons of water. I can't find any leaks at any time but I've assumed a hairline crack somewhere allowing water into the cylynder. It doesn't seem to be enough to show up in the exhaust though, so i'm stumped like you.

Just curious, but how would the cats stopping up cause a coolant leak?? If that's so, mine are coming off right now.

Just curious, but how would the cats stopping up cause a coolant leak?? If that's so, mine are coming off right now.

My cats like toplay in their water bowl...

Just curious, but how would the cats stopping up cause a coolant leak?? If that's so, mine are coming off right now.

I'm not sure of the conection between the two, just know that the water loss started immediatley after the cats plugged up.

My '99 was using coolant and after I filled it the gurgling sound started. It's the air trapped in the heater core. I removed the overflow cap, filled the tank, idled the truck with the heat turned to hot and the air was purged. No more gurgling. I added Prestone stop-leak and the coolant remains full.
[QUOTE=alnheath]I have a 2000 chevy silverado with a 4.3 and 60k miles on it. In the last three months I have had to put in about a gallon and a half of coolant in my truck( this is the first time in five years that I have had to put any in it). I have no visible leaks coming out of the truck and when I contacted my dealer about blown head gasket, they told me that if it has never gotten hot that it should not be a blown head gasket.