03 Tahoe - coolant hot warning
 

So we were heading to the beach today in the Tahoe (5.3L) and got a coolant hot warning from the dash. It was very low on coolant and causing air pockets to form in the system. It went into the red when idleing at a stop, I put in neutral at the red lights and kept the engine reved at 2500 rpm to push the air pockets thru until I got home to look at it, reving the motor caused the temp to lower to a safe level(well at least the guage went to normal). I take it super hot air was hitting the temp sensor? It was 2 gallons low:eek:, its the wifes car and I dont get to look at it as much as my truck. I noticed there was drops of coolant in our driveway for the last few days. But noting leaks after I refilled it with the dreaded dex cool, ( man that $h!t is expensive) and burped out all the air with the cap off.

Before I get dirty jacking it up & crawling under it to see if there is a leak I have a few questions.

1- Can coolant get that low if it has not been checked in over 2 years with no leaks?

2- Could the drops be from the surge tank blasing out the overflow line if a super heated pressureized air pocket releases the overflow valve on the cap? I ask this because when I opened it any know it was low it surged the tank to the top, then drained back into the system after the air was released.

3- last, is there any common problems with cooling systems that anyone knows of with this model, water pumps, hoses, etc..

Thanks in advance.

It can evaporate somewhat, I think two gallons is a much too large amount to have evaporated off. Be wary that you could have a leaking intake manifold gasket.
Check and tighten all the heater lines, radiator hose, etc.

make sure your over flow tank isn't leaking

Thanks for the replies, I will check those areas.

Check your oil too. Although if you got two gallons of coolant in there, I doubt the engine would still be running.

Will do, I will look at it tonight and see what I can find, its too hot out right now to lay on the concrete. I kinda have the feeling that its a slow leak from the water pump and its been leaking for a few months, I just dont drive it everyday, my wife does. I blame myself for not checking it as much as my truck.

I finally got time to look at this further, it is in fact a leaking water pump. I had to add a quart of dex today and noticed it wet coming from under the water pump. Its a very slow leak & it looks like I will have a days work coming soon on this one, same with my truck but it only looses a quart every 4 months. Typical , water pumps last about 5 ,6 years, its just time for them.

mike your 2500 looses water?

My 2500 Silverado pump
 

Yeah, the dealer told me a year ago when I had it checked before my move to Ca. They said "we can replace the pump for $700 some od dollars" pfffh, I said I will take care of it. I have only lost a little less than a gallon since then, not bad but still need to get it done before a failure.


I will do the Tahoe first since it looses coolant faster, about a half gal every month.


Here is NAPA's price for a new one for my 6.0 silverado, Any comments on NAPA's water pump qualitys? Its the same part # for my Tahoes 5.3 motor as well.<TABLE cellSpacing=0 cellPadding=3 border=0><TBODY><TR vAlign=top><TD colSpan=6>Water Pump - New



</TD></TR><TR id=ctl00_mainContent1_ucHTMLContent_ctl00_TrNoDeta il><TD id=ctl00_mainContent1_ucHTMLContent_ctl00_TdNoDeta il vAlign=center align=middle colSpan=6></TD></TR><TR id=ctl00_mainContent1_ucHTMLContent_ctl00_trDiscou nt><TD id=ctl00_mainContent1_ucHTMLContent_ctl00_tdDiscou nt vAlign=center align=right colSpan=6></TD></TR><TR vAlign=top><TD>http://www.napaonline.com/images/u_clear.gif</TD></TR><TR vAlign=top><TD vAlign=top><TABLE cellSpacing=0 cellPadding=0 border=0><TBODY><TR height=120><TD align=middle>http://partimages.genpt.com/partimages/670537.jpg

</TD></TR><TR><TD><CENTER>Click on image to see enlarged view</CENTER>
http://www.napaonline.com/images/u_clear.gif<INPUT type=hidden value=28589088 name=prrfnbr>
<SELECT id=ctl00_mainContent1_ucHTMLContent_ctl00_image_vi ew style="FONT-SIZE: 8pt" onchange=SetImage(this) name=ctl00$mainContent1$ucHTMLContent$ctl00$image_ view> <OPTION value=http://partimages.genpt.com/partimages/670537.jpg selected>Bottom</OPTION> <OPTION value=http://partimages.genpt.com/partimages/593259.jpg>Top</OPTION></SELECT>
</TD></TR></TBODY></TABLE></TD><SCRIPT language=javascript> function ViewImage() { var imgSrc = (document.getElementById('PartImage')).src; var newWindow = window.open(imgSrc, 'popup_win', 'width=450, height=450,toolbar=0, location=0,directories=0,status=0,menuBar=0,scroll Bars=0,resizable=1'); newWindow.focus(); } function SetImage(obj) { var imgUrl = obj.options[obj.selectedIndex].value; var imgTag = document.getElementById('PartImage'); imgTag.src = imgUrl; } </SCRIPT><TD>http://www.napaonline.com/images/u_clear.gif</TD><TD>Item#: TFW45005
http://www.napaonline.com/images/u_clear.gif
Price: $139.00
tax and shipping not included

Disclaimer: The stated price may vary from the in store price and may change at anytime.

http://www.napaonline.com/images/u_clear.gif
Attributes:
Product Features:These O.E. Equivalent Water Pumps Have A Unitized Seal To Protect The Bearings & Provide Leak-Free
Long-Life Performance. The 1-Piece Bearing Assy Has Factory Sealed Bearings That Are Computer Matche
# of Outlets:4
Material:Cast Aluminum
Rotation:Standard
Timing Belt Driven:No
</TD></TR></TBODY></TABLE>

Go ahead and use the Napa part. There is nothing wrong with napa parts. It will be way better than a auto zone part. The water pump is very common on these trucks. The 5.3 intake does not carry any coolant so you never have to worry about that.