5.7 Vortec ? (1 Viewer)

[Elbert]

for anyone running a 5.7 vortec:

Given the heater hose fitting in the intake manifold behind the ALT....do you have the heater hose running from that fitting to (a) the heater control valve or (b) the heater core pipe?

I'm having some issues with heat and wanted to make sure I have the heater hoses setup right.

I think I may have a air pocket in the heater core.

thanks

 

[tmxmotorsports]

The 5/8 at the thermostat housing is the hot in to the landcruiser the bigger is return back from the heater cores

 

[tmxmotorsports]

May want to try and bleed the air off on jack stands and see if that does it if the configuration is correct.

 

[Elbert]

The 5/8 at the thermostat housing is the hot in to the landcruiser the bigger is return back from the heater cores

OK, are saying the hose from the fitting at the intake should run to the heater core fitting, and the hose from the water pump fitting should run to the heater control valve? Just trying to confirm.

SBC Coolant flow and heater hose connection guide - https://flowkoolerwaterpumps.com/blogs/cooling-resources/small-block-chevy-heater-hose-connection One of the diagrams I found that suggests coolant flow through the SBC. Being hot water feeds from intake.....cooler water returns back via water pump fitting.

I'm just trying to confirm I have the connections at the firewall (heater core) correct and the related two hoses are going to the correct fitting on the engine side. I've bleed this "monkey" a few times now (lately) with front of truck elevated. I swapped thermostat yesterday and did the bleed process again, still no effective heat. Truck runs fine, temp range is fine, heater control vale is new and works, I"m bleeding using one of the funnels that mounts to the radiator neck and with heat on and I've let it run for 30 min or so. I fill the truck to capacity and then do the bleed process etc and I do get some air out using this funnel with front of truck elevated. With this thermostat swap the heater performance is now worse which is not good.

Conclusion on my part is (a) I still must have an air pocket in the heater core (b) I potentially have the connections at the heater core wrong (c) I have some type of blockage or restriction at the heater core. From memory I believe both sides of the heater core essentially run 5/8 hose, which is just an observation.

So...since I"m going to have to keep screwing around with it, I want to get the heater hoses correct, then I'm going to use one of those air powered coolant fillers that applies a vacuum to the coolant system and use same device to fill the system.

ON the FJ60 at the firewall, there is (a) heater core pipe for one connection and then (b) connection at heater control valve which feeds the other side of the heater core. My assumption is if I have the heater hoses plumbed wrong at the heater core I'm compounding my problem.

 

[tmxmotorsports]

Wait your running small block chevy 350 not ls if so nevermind what I said .post pictures of your setup.

 

[TrailBornRunner]

On my tbi 350, the hose coming off the intake manifold goes to the control valve, and the lower one goes to the water pump. Shouldn't really matter and sounds like you have a clogged heater core, should try flushing it manually and see what kind of flow you get

 

[Elbert]

I'm going to make some changes in the hose routing anyway as I don't like the heater hoses hanging off the passenger side where they get too close to the exhaust manifold. I may change the connections at the heater core / firewall. Heater core is "new" , was a OEM heater core with brand new core (I had radiator shop re-core it). I agree that it sounds like it might be crap in the heater core. But I'm leaning into a air pocket in the core. I'm going to screw around with it this weekend after I round some up some parts. And I'm going to use this (new to me) vacuum coolant filler and see what happens. ON the 5.7 vortec you have a coolant fitting in the intake manifold behind the alternator, and you have another fitting where the water pump feeds a hard line that goes under the ALT and out to the side (passenger side of engine). Not counting the wonderful bypass hose also that feeds off the water pump. I long ago removed the stupid "quick-connect" fitting in the intake and replaced that with a 1/2 npt * something barb fitting (its either 5/8 or 3/4) I've forgotten. Engine is basically stock GM OEM long block with an intake and other parts of a 99 Yukon (5.7 vortec) , I run stock type 195F thermostat, GM OEM water-pump. Truck runs fine as to temps, and so forth. The heater biz has been aggrivating....I'm hoping the vaccum coolant filler solves my problem, if not I'm going to flush the heater core and or replace it. no crazy tune.

I had a heater core leak last winter (some time ago) and over a long time of screwing around...I removed the heater core adn had it "fixed" and then I replaced it.....some time passes and here we are. I don't drive the truck that much but I plan to start and want it in better shape and the heater "suck" has to go, so here we are. Swapping the heater core now is last call but if Its somethign that has to happen I'll do that, but I want to see if this coolant filler helps address the air pocket that I believe is the root issue now. I'm nto sure it really matters which heater hose connects to which port on teh heater core, but if wrong I think it might make it harder to bleed air out (but thats just a view of mine) or it might make the heater less effective (again my view).