Recurring Low Coolant

siml8r5 · October 11, 2003

Hi Guys,

I have a 99 Silverado 1500 Z71. I started hearing a gurgling sound a couple weeks ago and though it was my imagination. 4-5 days later, the LOW COOLANT light came on so I refilled the coolant reservoir. About a week later, The light came back on and it is still coming on. Any ideas? I'm at a loss. I don't see any leaking or anything at all anywhere. Thanks guys, I would really appreciate any input. Thanks

tmf6902 · October 11, 2003

Is the coolant actually low when the light comes on, or is it just as full as it was when you filled it???

If you coolant level is fine, you probably just have something wrong with the sensor.

siml8r5 · October 11, 2003

No the coolant level is going down

doverarjim · October 12, 2003

Mine does the same thing!!! At first I saw it come on at one stop light that I seem to always get caught at both coming and going to work every day. Some times I can stop and turn the truck off and then restart it and it will go out. May be some tech can help with this one???? But I lose coolant and refill about every 6 or 7 weeks, truck has never run hot so boiling out is not an option.

raventai · October 12, 2003

if you cannot find an external leak you need to have your oil analized they will let you know is there is any glycol in your oil, if there is you may have a bad head gasket

Race18 · October 12, 2003

Mime did that for a couple of months I didn't have any water in my oil. I couldn't see any leaks til the end and thought it was tranny fluid. It turned out to be the heater hose fitting on the intake. GM made it from cheap pot metal and it rots out. Trust me change it with a steel one from NAPA for 6 bucks. If it breaks like mine did you will have to chip it out and re-tap the intake. Just a thought what might be happening to yours. I found out the hard way. Good Luck

frdfandc · October 13, 2003

Race18 is correct. More than likely your leak is coming from the heater hose fitting on the pass side front of the lower intake. One of my co-workers use to work at a GMC dealer, and he said that its fairly common for those to start leaking.

99-2door · October 15, 2003

Mime did that for a couple of months I didn't have any water in my oil. I couldn't see any leaks til the end and thought it was tranny fluid. It turned out to be the heater hose fitting on the intake. GM made it from cheap pot metal and it rots out. Trust me change it with a steel one from NAPA for 6 bucks. If it breaks like mine did you will have to chip it out and re-tap the intake. Just a thought what might be happening to yours. I found out the hard way. Good Luck

I haven't heard of that being a problem on the NBS trucks. Is it? you can also get the replacement part from GM and it is higher quality (different type metal) than the original.