I'm new to this site, and I've done a little looking around it and didn't find anything about my problem. So...

I got a 99 Tahoe about a year and a half ago with at the time about 78,000 miles. I got stationed here in italy and brought it with me. No real problems that I know of until now. I've noticed that my coolant resivior tank never hold any extra coolant. I'm afraid that I may have a leak some where. But i've monitored the vehicle numerous times (placed card board under neath and no leaks what so ever). In the past several months I've put in about 2 gals worth of coolant and the over flow tank is still empty. My tahoe doesn't over heat at all... but where is it all going to? I've spent many an hour in the hood and under the vehicle looking for maybe some sort of runoff but I don't see any fresh fluid any where. I don't want to keep dumping gallons worth of collant in there if its just going to leak out, so I'm hoping that it really is just low and I've been maintaining that level. Any ideas?

 

there is a big hose on a quick connect fitting on the passangers top-side.(I think kinda in the middle) that goes in the block. check that, make sure it is running and some what warm so you will have pressure and wiggle it around and see if any leaks. if thats not it, maybe a intake gasket.

 

thanks, I'll have to look tomorrow when it's day light again

 

Also check the "weep" hole on the sides of the water pump... mine leaked so little from there once stopped it took me months to figure it out....if I remember there are 2 weep holes. Also check the front edge of the intake near the thermostate as thats the location my lower intake started leaking as well.

 

Welcome to the forum.

If you can't find any leaks to fix, put a bottle of Bar's Stop Leak in it. If that doesn't stop it, then you have a very serious problem.

Have you checked your oil for signs of oil? Check the underneath side of the fill cap also.

 

Bars leak is not a good idea. I recently worked on a truck that the customer had put bars leak in 1-2 years ago. It made all the hose very soft and the started to swell. It actually started to seep through 1 of the heater hoses. I replaced the radiator, all the hoses the thermostat and rinsed the heater core out with brake clean and water.The old hoses weighed almost double what the new ones did. After I put is back together I flushed (after a flush chemical was run through) with 6 gallons of dexicool/ water mix. The bars leak was still rising to the top of the rad. It did stop his leak for a while but the end result was much worse.

You can go to the auto parts store and purchase coolant dye it will leave a stain where it leaks and will light up really good with a dye light or black light.

 

That's interesting that Bar's caused that problem cuz I used to use it in the used heaps my kids drove in their formative years and never experienced that. Also never stopped up a heater core with it.

I'm betting it's either water pump or internal which is either going in the crankcase or out the exhaust pipe.