I think I'm losing coolant

[ScottyBoy]

Last week my cluster popped up a message that said "Low engine coolant". I checked and sure enough, It was low. I ended up adding about a 1/2 gallon of coolant. A few days later, I checked it again, and the reservoir was low. I added about another quart or so. Same thing 4 or 5 more days later.
I've looked high and low and I can see no visible coolant leaks. There is no coolant in the oil either. Is this normal to just use coolant over time? I've never added any more than maybe a 1/2 gallon of coolant in the 5 years I've owned this truck. Should I drain and flush the cooling system? I've never done it yet since I've owned it, and I have almost 100k miles on it now. And I have a 2001 Suburban with a 5.3 liter engine if that matters.

 

[Rivieraracing]

Need to look under the water pump and see if you see coolant or even wet looking spots below the shaft at the weephole or even around the water pump where it bolts up to the block!! Also, take the overflow/expansion tank off of its holder and see if there is a crack or something around on it to let coolant leak out! Is you passenger seat carpet wet, might me a bad heater core! Check over all your hoses and make sure the clamps are tight! Might also be leaking at your radiator, might wanna take your shroud off and give it a good look over! Just some stuff to look for, good luck and let us know what you come up with!

 

[Tahoewhat]

scott,
My coolant dissappears also mysteriously. But i think i have found that my water pump is going bad. I was finally under the front end, half way under it, and saw it leaking on the block by the a/c compressor. Didnt see it leaking from the water pump weep hole, but thats the only thing there.
Might want to check that out like chris said. I think our trucks are known for those going out.

 

[ScottyBoy]

I did a close inspection today and I finally found it. Its leaking from the weep hole on the goddamn water pump.

---------- Post added at 09:19 PM ---------- Previous post was at 09:16 PM ----------

I also read on another site that these truck ae notorious for the water pump gaskets leaking even though the water pump is still good. Sounds like thats what you have Mike. Mine is definitely coming out the weep hole. I need to change my pump now. I don't even have the damn money right now for a pump.

 

[Rivieraracing]

Glad you found the problem, the pump isn't cheap but changing it out was a piece of cake!!

 

[Tahoewhat]

I did a close inspection today and I finally found it. Its leaking from the weep hole on the goddamn water pump.

---------- Post added at 09:19 PM ---------- Previous post was at 09:16 PM ----------

I also read on another site that these truck ae notorious for the water pump gaskets leaking even though the water pump is still good. Sounds like thats what you have Mike. Mine is definitely coming out the weep hole. I need to change my pump now. I don't even have the damn money right now for a pump.

Huh, no one ever said anything to me about the gasket being bad. Im going to look into that.
Heres a question, when you looked at your pump, the weep hole how did you notice thats where its coming from? Did you have the truck on? I havent really looked real close at mine yet. But now i need to see if its the pump or gasket? You know, maybe the gasket is why i dont loose coolant that bad, sometimes it will be almost gone, then others its fine, just a little low. ( i check it every day)
Dont want to accept it, but finally have a little money to fix it.

 

[Rivieraracing]

It could be the gasket Mike, the truck doesn't have to be on to see the coolant leaking if that is the problem, just wanna look for an area that looks damp or wet that shouldn't look that way!! If in doubt on an area, try to get up in there with a towel or something to clean the area of any dirt or moisture till it looks dry and drive it around for a bit and check again!! You need to get under your rig with a good flash light and see under the area of the pump and see if it has any wet spots, or you can also get a little mirror since you dont' have the belt driven fan and from the engine compartment reach down and look up under the pump with the mirror and a light!!

 

[ScottyBoy]

Yeah finding the leak is a *****. I looked like 6 or 7 times so far and didn't see any leaks until today. It must have been evaporating really fast because I looked right after I had driven it and the engine was hot. Yesterday when I looked, Ihad driven it about a mile or so, thats it. Then I looked all around and undeneath again and that when I saw some coolant near the water pump. Upon closer inspection I could see it dripping out of that weep hole.
And Chris, you said its a peice of cake. Does anything have to be removed besides the air intake tube and the fan? I know older chevy engines I've worked on, every bely driven accesory has to come off to get the damn water pump off.

 

[Rivieraracing]

It's a piece of cake for those with electric fans, one less pain in the *** to have to deal with!! Taking the fan off is the hardest part, just get an air chisel and spin the nut off by using the chisel at one of the nuts corners to spin it loose!! Worked great!! Otherwise if I remember right, find the main belt tensioner, put a wrench on the nut and turn the tensioner until the belt loosens, just remember how the belt was routed before you take it off!! The rest was pretty easy, just be sure to change out your thermostat while you are at it, it's cheap insurance and it's on the water pump, can do it on the work bench!

 

[hoe]

Huh, no one ever said anything to me about the gasket being bad. Im going to look into that.
Heres a question, when you looked at your pump, the weep hole how did you notice thats where its coming from? Did you have the truck on? I havent really looked real close at mine yet. But now i need to see if its the pump or gasket? You know, maybe the gasket is why i dont loose coolant that bad, sometimes it will be almost gone, then others its fine, just a little low. ( i check it every day)
Dont want to accept it, but finally have a little money to fix it.

thats the most common problem. Minded it will heal a leak, but when it start back to leak again, its just not worth it, when you discover its the pump. I tried the cheap route 5 times, and ended up replacing my waterpump 6 times, and If I just bought the new pump and swaped it with new gasket, I would have swap it once to begin with, and have no leaks.

Also these trucks are known to have cracked coolant resivors and faulty coolant level sensors.

And you dont absolutely need to remove the fan, but you can if you want too.