2000 Silverado 4.8 Losing Coolant?

Yesterday driving home from work (65 mile commute) about 5 miles from home, the low coolant level light came on, temperature stayed fine at about 180 which it always runs at, got home, let motor cool down, looked for leaks, didnt see anything, so added coolant to full level...on the way back to work today, halfway here, low coolant light came on again, and again tempurature stayed the same...so i made into work...when i got here, i popped the hood to take a look, and you can hear like a tiny hiss (like a small drop of water hitting a hot surface) and a puff of steam coming from the BACK of the engine...but again no leaks on the floor...

what should i look at first?:banghead:

Yesterday driving home from work (65 mile commute) about 5 miles from home, the low coolant level light came on, temperature stayed fine at about 180 which it always runs at, got home, let motor cool down, looked for leaks, didnt see anything, so added coolant to full level...on the way back to work today, halfway here, low coolant light came on again, and again tempurature stayed the same...so i made into work...when i got here, i popped the hood to take a look, and you can hear like a tiny hiss (like a small drop of water hitting a hot surface) and a puff of steam coming from the BACK of the engine...but again no leaks on the floor...

what should i look at first?:banghead:

after the engine cools down for a while with a good light look from under the vehicle for where the coolant stains are then follow up to the head gasket area...then top of engine intake area ...usually coolant leak will run to the back of engine with the front being higher..

removal of the air intake rubber ducts is also needed for a full coolant inspection..

Put a pressure pump on it and it will not be intake gaskets,there are no coolant passages going through the intake.

i found the problem...the plastic nipple that the heater hose connects to the heater core at the firewall had a tiny crack in it...its dripping there...but now where do i find these parts, and how do i get them off???

Parts place or dealer should have somthing for it.
Have a good look at it and see if there is a plastic lock on the fitting.
Also Is there a metal pipe out of heater core that you can put a heater hose and clamp on it?
Where does the other end of the heater hose go to?
What kind of fitting on other end?

I dont know what the part is called...when I call part stores, they dont know what I am talking about..they say to bring the part in...but i can get it off..there is a metal tube coming out, but they both (inlet/outlet) have a plastic nipple thing on it that wont pull off?

Go to your GM dealer and see if he has one.
If so ask to look at it and check the lock clip out on it.
Most good nice parts men will tell you how to unlock the clip.
And if does not cost a arm and a leg by it from the and install it.
Good Luck

Im wondering if i can cut the cheap plastic connectors off the metal tubes, and then just put the hose straight to the metal tubes with a hose clamp?

If there is enough on pipe sticking out of heather core.
And you can get it cut off without cutting the pipe.
Do not twist or pry on the heater core pipe or you will be buying a heater core.

The GM kent Moore tool J 43181 is used to disconnect it.
Some parts places and tool dealer may have a tool to disconnect it.
Good Luck

yeah i just seen that i can get the quick disconnect removal tool at kragen autoparts for like $10...ill go ahead and buy that so i can get the parts off...but i think im going to try to hook the hoses straight up to the metal inlets...

I dont know what the part is called...when I call part stores, they dont know what I am talking about..they say to bring the part in...but i can get it off..there is a metal tube coming out, but they both (inlet/outlet) have a plastic nipple thing on it that wont pull off?

I never messed with the heater hose connnection at the fire wall..these are a quick disconnect fitting..use of a tool is used to release the hose..replace hose or cut off and use a clamp with the cracked fitting discarded...

so i just disconnected both the inlet and outlet heater core hoses, and hooked them together using a "emergency heater hose repair kit" i found at Kragen Auto...being in Southern Cali, I dont use my heater that often, does anyone think this will be a problem to run it like that for a few weeks to i can get under the hood again?

so i just disconnected both the inlet and outlet heater core hoses, and hooked them together using a "emergency heater hose repair kit" i found at Kragen Auto...being in Southern Cali, I dont use my heater that often, does anyone think this will be a problem to run it like that for a few weeks to i can get under the hood again?


No problem.
You should be OK.
But.
Before you get ready to fix it find a disconnect tool for it.

No problem.
You should be OK.
But.
Before you get ready to fix it find a disconnect tool for it.

yeah i ordered the tool online..should be here shortly...i just was worried about that fix holding up, because i drive 62 miles each way to work and back...

Good splice in and clamped good should be Ok.
But keep a eye on it.
Good Luck

i got it double clamped on both sides of the splice...only thing i am concerned about is the plastic splice tube...will it hold up to temp??..

i got it double clamped on both sides of the splice...only thing i am concerned about is the plastic splice tube...will it hold up to temp??..
Heavy plastic may work.
But.
I never did like plastic where there is a lot of heat.
I would just use heater hose.
Good luck

My heater core started leaking in May. I routed the hose away from the hetar core until last week. It ran at the same temp so you will be ok.

I had to remove the adapters that you are looking to replace. I was able to do it with metal picks and a very small flat head screw driver, but I had the heater core in hand. The tool you mentioned should work , but, if you still have problems, take 4 small strips of sheet metal 3/8" wide just thick enough to make a solid folded crease about 2" from the end of each and put the 2" end around to the inside of the coupler against the heater core tube and pull outwards.

There are four tabs that lock that coupler on the tube as they pass over a ridge on the heater core tube. With some persuasion, you can get the tabs on the inside of the coupler to release.

You can see the tabs are lined up with the 4 flat spots.
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