Radiator, how big is too big!

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Diggerauditor

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I have an 2001 Expy Eddie Bauer 4x4. My radiator developed a leak so replaced it. The vehicle has A/C, Towing, and other acc so I ordered the HD radiator thinking that's what was in it. To my amazement, when I pulled it out it had a 2 row in it. I had bought a 3 row, figuring bigger is better for radiators I installed. Ever since then my heater only spits out luke warm air. Is the radiator too big for the vehicle? Is there anything I can do to increase the heat output of the heater, short of replacing the radiator with a smaller one. I hate to resort to putting a pizza box in the front of the radiator. I've changed the thermostat twice, thinking mb it was stuck open, but to no avail. Any thots would be appreciated.

Thank you
 

AbbadonTD

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May sound silly, but you added more coolant too right? Bigger Radiator = more coolant needed.

I never had problems with bigger radiators in things, usually the difference in warm up time is unnoticeable, cold vs warm is much more to notice that warm vs warmer.

Did you flush your heater core when your replaced your radiator? you could have knocked something into it in the process of pulling the old radiator, slowing the flow.
 

docraymund

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It depends on where you live. If you need to use the heater more often than the a/c then go for the stock 2 row. Having a new 2 row rad means better heat transfer bec. the rad fins are new so heat dissipates quickly.
 

1955moose

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I've put 3 row radiators in many vehicles in the past. I never had a heater issue. Make sure you get all air out of radiator and system. Feel the inlet and outlet to heater core, both should be warm. Check some of the earlier threads on first edition heater problems, if these things don't work. Also replace expansion tank cap, their cheap enough. If all worked we'll before and you have pressure, it's probably trapped air. Theirs videos online that show proper burbing procedure.


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AWD EXPY

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I used to have a mazda, that the temp gage barely got close to the normal op range. There was very little heat.

I put a higher temp rated thermostat in it and the gage read close to the middle of the range, and I had good heat.
 

stamp11127

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I thought heat transfer rate was based on contact area between the two areas of temperature difference, not the newness of the material. Dirt and trash on the fins will have an insulating effect and reduce the radiators efficiency.

Adding an drastically oversized radiator in an environment that would reduce the radiators outlet temp far below the operating temp of the engine would be the only cause of lower coolant temps such as you think you are experiencing.

An example would be a big truck radiator on a 4 cylinder engine in the artic when it is -70 with wind blowing through the radiator fins.

Check the flow into and out of the heater core and the hose temps once the engine is at operating temp.
 
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ExplorerTom

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Where do the heater hoses come out? Is that coolant regulated by the thermostat? Or is it on one of the bypass hoses?
 

stamp11127

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Depends on the engine for location but the smaller hose is pressure and the other is return. I think the return is the line that goes to the water pump.
 
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