No heat after LS swap.
 

I installed a 01 6.0 dbc in my 72 GMC last year near the end of summer, and didn't get much heat at all from the cab heater. Put it away for the winter around October 1 last year. So, I get it out last weekend and it's 40* here in Indiana and I'm not getting much heat out of the vents. Fan blows good but it's mostly 60-70* air. Temp gauge always runs at 180*. I thought maybe swap my 2 heater hoses around on water pump and see what happens. I installed new water pump and t-stat when LS was installed last year. Truck has a/c too but not hooked up yet. What to do?

Re: No heat after LS swap.
 

Clogged heater core?

Re: No heat after LS swap.
 

That's going to be what I check next. How hard is that to change? Go at it from the inside or outside?
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Re: No heat after LS swap.
 

Factory AC will come out from the inside. Good luck.

Re: No heat after LS swap.
 

yes sir, thats what I need.

Re: No heat after LS swap.
 

hook a garden hose to your heater core and see how it flows?? it might be as simple as it being air bound.....if you think its a cloggged core try unhooking the hoses from the block and draining the water out keep one hose up high and fill it with CLR and let it sit for awhile then hook the hoses up backwards and flush it out then try that......but my real guess is air bound

Re: No heat after LS swap.
 

Ya, I hear some gurgling down there by heater core sometimes. Thanks guys.

Re: No heat after LS swap.
 

Clogged heater core it was. Blew air through it with air nozzle, then jet stream on garden hose. Works great now. Thanks.

Re: No heat after LS swap.
 

Love it! I know I tend to panic when something like that happens, glad it worked out for you.