Inadequate Heat

[LateOnTheBrakes]

Did the poor heat condition exist before the engine swap?

Bought the truck without an engine.

 

[LateOnTheBrakes]

Did the poor heat condition exist before the engine swap?

I was going to suggest the thermostat. Check your engine temp gauge or if you have an idiot light, use a thermometer to check the engine temp. If your thermostat is stuck open, you wont get much heat.
Also, make sure there's no air in the system.
It's usually one if not both of those problems.

No idiot light. Digital readout.

You must be registered for see images attach

 

[LateOnTheBrakes]

The water circulates with the thermostat closed or open. I know it's getting up to temp.

You must be registered for see images attach

You must be registered for see images attach

 

[bucket]

Bought the truck without an engine.

My thoughts are either the heater core is partially plugged up or the blend door is not fully closing in one direction.

With the truck running and up to temp, both heater hose connections should be good and warm. If one is significantly warmer than the other or if neither are as warm as the radiator hoses, then the core is plugged. If both hoses are hot, the problem is likely with the blend door.

 

[LateOnTheBrakes]

xc_hide_links_from_guests_guests_error_hide_media

xc_hide_links_from_guests_guests_error_hide_media

 

[AuroraGirl]

By chance, how long are your hoses from the water pump, can i see them? Is it while moving, or just all the time, and you live in Cold temps rn right? Or is it warmer there like its been some places in the US rn lol. yesterday was 10s, today its 30s. day befroe 60s. day before, 10s.

 

[SirRobyn0]

My thoughts are either the heater core is partially plugged up or the blend door is not fully closing in one direction.

With the truck running and up to temp, both heater hose connections should be good and warm. If one is significantly warmer than the other or if neither are as warm as the radiator hoses, then the core is plugged. If both hoses are hot, the problem is likely with the blend door.

X2 on this, it's the first step we take after checking the coolant level at the shop.

 

[AuroraGirl]

The LS has dedicated outputs for heater core.

You must be registered for see images attach

whats your electric cooling fan behavior like too

 

[LateOnTheBrakes]

Normally I have the triggers set on at 195, off at 180. I have them set to 210 and 215 right now trying to see if it's warmer. It's almost 60*F here, but 40s in the morning.

 

[AuroraGirl]

Normally I have the triggers set on at 195, off at 180. I have them set to 210 and 215 right now trying to see if it's warmer. It's almost 60*F here, but 40s in the morning.

well your fans were coming on way too early probably keeping it a lot cooler . Do they have factory low-speed on one fan, high on 2 setup? or on/off

 

[SirRobyn0]

well your fans were coming on way too early probably keeping it a lot cooler . Do they have factory low-speed on one fan, high on 2 setup? or on/off

I'm not going to say that is or isn't your problem but it could be attributing to it. Most production vehicles don't turn their fans on until 215 or 220

 

[LateOnTheBrakes]

The Holley EFI triggers were set that low to start with. But it's been set at 215 for the last month when I noticed I was having to wear a jacket when I drive the truck to work. I have the 454 HD radiator, Tejas Steelworks fan shroud, and two 13" Spal fans. I can set the triggers where ever I want.

The heater core didn't look bad enough to replace considering I will probably do a vintage air upgrade if I can figure out how to install the AC compressor without spending $2000 on a new accessory drive system.

 

[AuroraGirl]

The Holley EFI triggers were set that low to start with. But it's been set at 215 for the last month when I noticed I was having to wear a jacket when I drive the truck to work. I have the 454 HD radiator, Tejas Steelworks fan shroud, and two 13" Spal fans. I can set the triggers where ever I want.

The heater core didn't look bad enough to replace considering I will probably do a vintage air upgrade if I can figure out how to install the AC compressor without spending $2000 on a new accessory drive system.

can you aggressively(chemical) flush it to see if it has mineral or silicate type buildup inside coating the surfaces

it may , as a brass, have larger passages because they tend to like rads, but can be flowy still despite that

saw it on my kawsaki, thick calcium buildup coated the entire cooling loop. weird

 

[AuroraGirl]

It's not brass. It's aluminum and looks really good. Thermostat is less than a year old and I know it's opening, but the heater core output on the LS is before the thermostat. Dexcool.

nvm i miss-remembered. so its not originalthen?

Is your radiator brass/original?

 

[AuroraGirl]

also we are using holly sniper, not a GM PCM. Can you look at previous questions about the fans programming, if you have high/lowspeed relay controls, how your surge/expansion tank setup is, how long hoses, etc
And is your dexcool not mix? youi may have put concentrate accidently and your truck is just really good cooling system so it manages to work (jk But its possible its not 50/50?) cap condition?