Problem after installing upgraded radiator

[LordWayback]

Are you using a scan tool to read the temp, or using the cluster gauge?

those temps are cluster but the scan tool was reading true to the gauge

 

[SpareParts]

But your scan tool and gauge are reading from the same sensor.

 

[LordWayback]

But your scan tool and gauge are reading from the same sensor.

I used both because Chebby gauges are known to be not functional

 

[OR VietVet]

You can use a worm gear hose clamp.

 

[Marky Dissod]

View attachment 470226

The vice grips make it run 190F on the freeway and 200F in town

You can use a worm gear hose clamp.

Or, more than one. Now you can regulate flow through that hose.
In winter, go ahead and squeeze it tight - NOT shut.
In the summer, or whenever you tow / haul heavy, or play hard, open it up all the way.

By the way, forgot to say that you may need to burp air out of the system, but I doubt it since you're running cold.

 

[LordWayback]

Why was the radiator upgraded in the first place? Was the truck overheating?

Looks like it's aluminum? Upgraded to aluminum? What are the specs on the upgraded radiator?

I was tired of blowing up the plastic ones on the seal on the side tanks basically bigger everything except ports and I guess it didn’t have the restriction that’s needed in winter

 

[Suburban04]

Now that winter time has come I’m needing to defrost the windows in the morning. and the truck barely wants to warm up at all with the radiator upgrade I changed the thermostat for a 187* factory spec and it’s barely warm at all. I’m thinking I need electric fans to keep the truck at temp at idle if I sit a really long time without the heater on it starts climbing to the desired temperature but it’s only 55* outside when picture was taken and I took it on atleast 10 minutes of highway is this just how it is with the aftermarket radiator? It’s making me late for work when I would normally have plenty of time I’ll update tomorrow if it warms up in time it’s gonna be high 30’s at 6 am tomorrow and it’s struggling now.
View attachment 470191

There is a technical service bulletin out that explains what happens. If you look at the old factory radiator the smaller hose where it goes from the radiator to the coolant reservoir. The nipple on the radiator that the hose attaches to is restricted. When I put in my aftermarket 3 core aluminum radiator that nipple did not have a restrictor I actually made one out of a piece of aluminum bar stock. I have attached some photos below of the restrictor that I made. So far I haven't had any problems with it

 

[Marky Dissod]

When I put in my aftermarket 3 core aluminum radiator that nipple did not have a restrictor,
I actually made one out of a piece of aluminum bar stock. I have attached some photos below of the restrictor that I made.
So far I haven't had any problems with it.

Is it removable or adjustable?
Because it'd be pretty damn cool if it were somehow adjustable.

 

[RET423]

That small hose is the steam vent, it's not causing your issue

Your blend door could be failing to move completely to the heat position, your heater core could be restricted or your thermostat could be stuck open

I doubt it's your thermostat because even 140 degree water will blow pretty warm air if the heater core is flowing well & the blend door is all the way to the heat position

Remove the blend door actuator and see if the door moves freely, if it does observe the actuator as adjust from cool to heat & see if it's rotating freely; my guess is that actuator has failed

 

[Fless]

That small hose is the steam vent, it's not causing your issue

Your blend door could be failing to move completely to the heat position, your heater core could be restricted or your thermostat could be stuck open

I doubt it's your thermostat because even 140 degree water will blow pretty warm air if the heater core is flowing well & the blend door is all the way to the heat position

Remove the blend door actuator and see if the door moves freely, if it does observe the actuator as adjust from cool to heat & see if it's rotating freely; my guess is that actuator has failed

The small hose between the radiator and the surge tank is not a steam vent. If the radiator orifice is too large the coolant temp will not rise to the desired temp. Hence the necessary restriction, whether that's inline or integrated into the radiator port.

 

[RET423]

No it's not but it won't effect the heater as the heater core gets circulated water from the block, not the radiator on an LS; that's why you can't block off the heater hoses if the core fails like the old engines, those heater hose ports must be looped if you have to temporarily remove flow from the heater system

The thermostat controls the water temp in the block an insufficient radiator can make the engine run hotter than the thermostat rating but a more robust radiator cannot cause it to run cooler than the thermostat rating if the thermostat is opening & closing as it should

 

[RET423]

The OP is troubleshooting a heater that won't blow sufficiently warm air, that TSB is for correcting an OBD code for the engine not warming up fast enough or to the temp the ECM is looking for

That code also sets when you replace a thermostat with a colder rating than stock as it only requires a few degrees to set it, but that small fluctuation is not going to translate into a heater not working enough to leave for work in the morning; which is the problem the OP is experiencing

If he was just trying to to get rid of the code for insufficient coolant temp there are several options including that restrictor which could help (but a better option is to lower the temp setting in the ECM that sets that code in my opinion)

But whichever method is chosen to stop that code from setting is not going to have such a significant effect on the heater performance as to make the heater fail to warm up the cars interior, my advice to him is based on the problem he is experiencing; I don't think his radiator working too well is causing his heater issue

 

[Fless]

These cooling systems will warm up fine if everything is in operating condition. However, it's been well documented over and over here if that restriction in the surge tank line is too large, the engine temps will not come up all the way, which may be happening here.

Before condemning any particular part or taking action to change ECM settings, I think we need a little more specific info:

1. When the engine is fully warmed up (as much as it will) what is the engine coolant temp (ECT) sender reporting with a scan tool?

2. Does pinching off the surge tank hose have any effect on the engine temp?

3. Has an infrared temp gun been used to determine if the ECT sender is close to accurate?

 

[OR VietVet]

These cooling systems will warm up fine if everything is in operating condition. However, it's been well documented over and over here if that restriction in the surge tank line is too large, the engine temps will not come up all the way, which may be happening here.

Before condemning any particular part or taking action to change ECM settings, I think we need a little more specific info:

1. When the engine is fully warmed up (as much as it will) what is the engine coolant temp (ECT) sender reporting with a scan tool?

2. Does pinching off the surge tank hose have any effect on the engine temp?

3. Has an infrared temp gun been used to determine if the ECT sender is close to accurate?

Yea, assumptions cost money.