Middle of radiator cold, sides hot?

solowiej

solowiej

New Member
Hey, My 97 V6 gets hot in traffic but cools fine while it's moving. Fan is working. Pump is working. Coolant is flowing.

I started it cold and found that with both Left and Right sides getting hot (180 and 185F), the center was still at 89 degrees.

Is it possible that the radiator is somehow plugged in the middle but fine flowing from side to side? It's worth noting that the fan and shroud direct the cooling air right through that middle of the radiator... any chance it's just getting all the nice fan air there and cooling down that well?...

But if the air is cooling that center part so well, why would the left side (facing the truck - outlet side) and outlet pipe still be nice and hot?

Any insights are appreciated before I pull out this radiator!

Sean
 
I agree with Rock, sounds like your core is partially plugged.

Good radiator shops are getting harder to find, and most just re-core now. Two choices, either re-core your old radiator, or purchase a new one. While it is drained, a new thermostat, belts and water pump as well, unless those were recently replaced trying to track down your overheating problem.

Edit: Welcome to the forum!!!
 
I agree it seems plugged. What bugs me about it - and maybe I'm overthinking this - is that hot coolant comes in the top left corner (facing the truck), goes out the bottom right. How can the middle be staying cold and yet have hot coolant passing through?

1) it's blocked somewhere
- meaning coolant is not getting through, so why are both corners hot?

2) the fan is cooling the center of the radiator that well because the fan shroud directs all the air through the center
- I could remove the fan belt and test if it still has uneven hot/cold spots without the fan going
- I can spray clean between the radiator fins to see if the sides may be clogged with debris

any more thoughts? Or just order a new radiator already...
 
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what mileage is this happening at?
i have not yet experienced this issue
 
@solowiej

If you look closely at the fan shroud, you should see the shroud allows the fan to pull cooling air across the entire radiator surface.

Pull the radiator, take it to a radiator shop. Tell them the problem. They will solve. Generally, the cost is reasonable. Possibly less than a new radiator.

Although, the radiator is a passive part, it does need maintenance. The maintenance is a simple drain, flush, replace coolant at the service interval and keep the exterior free of debris (bugs, leaves, road trash...), gently straighten any fins.

Fins are fairly fragile. Use something soft like a wood popsicle stick.
 
Rock is spot on, however instead of a popsicle stick, get an HVAC fin comb. These are a bit stiffer than the popsicle stick, and are made specifically to straighten fins. The one I use and have been using for decades is combination comb/brush, in that it uses stiff metal bristles that can be used in multiple fin sizes, and cleans and straightens at the same time. I got mine at a pro HVAC supply house. As long as you don't try purchase any refrigerant, they should sell you a good brush, besides, you can use this to keep your HVAC condenser for your house squared away as well.

Click me to see an example
 
Last time I had to straighten fins was when we had lil monsters running about the house. Wood popsicle sticks were common and FREE.

My first thought was to use a flat blade screwdriver......but had 2nd thoughts to use a wood popsicle stick.
 
What you've got is a typically partially plugged radiator. The flow is actually greater on the sides and the center slowlyu plugs if not maintained. DO NOT!!! use a chemical radiator / block flush. As mentioned find a shop (especially with the cost of Vet radiators) or if you like spending lots of money buy a new one. DO NOT!!!! buy an aftermarket off Ebay or some such.
 
Turns out the center was cool from the fan working so well. I towed a 1300lb lathe 400 miles in a heavy trailer with no overheating issues, even when standing still. The one thing I changed was to fully shut off my heater core valve in the engine bay. The hot/cool dash control cable wasn't set up well and it was staying open. Now I'm thinking the heater core has been causing my overheating issues. Possibly clogged and/or leaking, as there have been coolant smells while the valve was open. i need to test it with the heater valve open again to verify before I rip apart the dash.
 
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