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2008 Town & County Running Hot

My Town & County started running hot… sometimes… I first replace the thermostat, but still ran hot. But I never saw any indication in the engine compartment of overheating or bubbly fluid or such, so I took it to the dealer, where at first it ran fine. Then started running hot, they were confused because the lower hose was a lower Temp then the upper hose so they wanted to take the water pump off and look at it. I asked if they verified that the engine was actually running hot, I also questioned them about the lower hose temp, because I think if its working right it should be a lower temp. They said would check both items. Then they called back and said they thought I had a blocked radiator (no mention of the water pump) and wanted $900 to put a new one in. I checked and I could buy one for $200 and can put it in. Got van back, drove it home and check the radiator and there were some cold spots and hot spots in the radiator. Called local radiator place and they suggested I flush it. I did, it ran perfect for 1.5 days and now overheats again. Now most of the Radiator is cold to the touch just around the edges is hot. the upper hose is hotter than the lower hose and is hot all the way to the radiator (maybe not as hot at the radiator as by the thermostat.
Question: Bad Radiator or Bad Water Pump?

It’s shows all the signs of being a bad (plugged) radiator.

I agree.
A flush cannot be expected to always recover a radiator with plugged up tubes. It was probably worth a shot, although I never recommend it, but cold and hot spots suggests the tubes are shot.

I’m also not a fan of “recoring” a radiator (if they even still do this). If it’s shot, just get a new one.

Once a radiator is plugged it’s done. There’s no way to effectively flush out a radiator on a late model car, the size and shape of the tubes is a far cry from what it was 30 years ago. If there are any cool spots in the radiator replacement is in order.

Fantastic, I’d not run into this issue and was not sure if it was the water was blocked or not being pumped. Blocked seems to be the consensus, I’ll order a new one today.

While I was waiting for delivery of the radiator, it ran perfectly, never going above mid-way and the radiator being uniformly warm over the surface of the fins. I thought well I guess the air bubble or something freed up and all is good. Drove it for about a week no problem, now yesterday it reported overheating again and the radiator is cold to the touch again.
Will a radiator blockage behave this way? Or what else could it be? Might the new thermostat I installed as the first step, be bad from the very beginning???

I wonder if you have a radiator hose delaminating and a flap or piece of it is blocking flow?

Another update, I completely removed the thermostat, the temp gauge is still getting higher than mid-way bouncing around 1/2 to 3/4. When I stop and feel the radiator it seems somewhat uniformly warm, but just warm. I can grab the upper hose and hold it all the way down to the thermostat housing. the last time I drove it, I got home and the gauge was between 1/2 & 3/4 (just below 1/2 was the normal temp reading). I was able to hold both the upper and lower radiator hoses, so risked opening the radiator cap. I was able to stick my finger in the warm fluid.
The hose flap may be a possibility but it would have to be the lower since I took off the upper today and it seemed correct.
But could I have had or developed multiple problems? Bad Thermostat, bad new thermostat, and now a flaky temp sensor? Could the running hot because closed thermostat cause the temp sensor to go flaky?
I’m kind of at a lose, but really don’t think the coolant is now running as hot as either the Temp sensor is saying, or as hot as it was running with the thermostat.

I had 1 car the lower radiator hose would collapse due to low flow from the radiator and the pump drawing more than the radiator could deliver. Complete flush, new radiator and lower hose is what I would do if it was mine.

Assuming cooling system has had is routine maintenance done on schedule.

Not entirely clear on this. Are you saying you’ve installed a brand new radiator and it is still overheating? If so, did you also install a new radiator cap at the same time? A malfunctioning cap can cause overheating symptoms like this. Removing the thermostat can cause erratic behavior in the cooling system, depending on the car it can be really erratic or just a little erratic. Your problem will be harder to diagnose with the thermostat out. Best to test the thermostat in a pot of hot water with a thermometer to make sure it is working and opening at the correct temp and the correct dimension, if necessary buy a new one (test that one too) then re-install the thermostat.

Once you have a new radiator and known good thermostat, if it still overheats, hmmm … well, it could be from among

  • Water pump is on the fritz
  • Coolant path Blockage
  • Temp Gauge sender is on the fritz
  • Too lean of a mixture
  • Ignition or valve timing is off

For the last two, first thing would be to read the diagnostic codes.

On the hose temps, my guess is – in a properly operating cooling system – that the lower radiator hose would be cooler than the top hose in most situations, maybe not so much at idle. You might consider purchasing one of those non-contact laser-guided infrared temp measuring gadgets. It will be easier to determine hot and cold spots, no need to use our fingers. I’ve seen them priced at less than $50.