2001 5.3 Heater Core Replacement

[kevin77]

I have a 2001 Sierra 5.3 that has a heater core leak. I have had a faint smell of coolant in the cab for the past couple years on and off and of course the bubbling sound. I just replaced my water pump and the coolant smell is very noticable as well as the heater fogged up the windshield this morning. I have read that the A/C will have to be evacuated to replace the heater core. Is this required and do you have any suggestions on the heater core replacement? Your help is greatly appreciated!

[Zembonez]

This is a fairly major repair.

 

The gurgling sound just means that there is a small amount of air trapped in the system. My 01 did it when it developed an intake coolant leak (4.3) but the water pump fix on yours could have left an air pocket in the system.

 

Point is... First you want to MAKE DARN SURE that the heater core is actually leaking. Do you have any coolant in the floor? Is there anything that would make it obvious that it is leaking? Coolant odor is elusive. Underhood smells can easily permeate the cab, making you think they are inside.

[kevin77]

The smell of coolant in the cab is strong and the windshield fogs up once the truck gets warm, but there is no coolant on the floor. I can only assume it is the heater core but if there you have any other suggestions to try before I dive into this it would be greatly appreciated.

[silveradobobby]

Thats a good sign its the heat core the way the core is in the heater box when you are driving the coolant goes out the condensate tube for the ac so you never see the coolant in the floor.

[kevin77]

Thanks, I did see coolant dripping from the condensation tube on the firewall.

 

Do you recommend replacing the evaporator while I am in there?

[silveradobobby]

i wouldn't change the evp just wash it out, they dont have leak problems.

[dickey]

hope you get a reply kevin i ahve a 2000 silverado that started steaming window 2 days ago looks like a big job i checkd warranty it calls for 10 hrs not lookin forward to that hopefully we can get some good tips

[silveradobobby]

Depending on your tech skills plan on a weekend off for you. A dash removal is in need and a quick connect tool is required to make it easier and an ac recover. If I remember correctly I could be wrong but I think this is right.