Hey Guys, This is my first post here.

I'm loosing my mind. I can't figure it out, I have a 2001 T&C that's keeps overheating and the air goes from hot to cold. Went through $150 in coolant so far.

These are the symptoms,
Start up T&C check coolant - fill it up - let it warm up - fill again let all the air out - put cap on and go take it for a drive.
Temp gauge starts going up and down about five to ten minutes into it.
Heater works great for the first 10 minutes. Then the cold air starts, then heat then cold.
Losing coolant somewhere (thinking overflow tank).
Will not overheat at idle only when driving.

I'm going to tell you what I've done to get it out of the way.

Had a leak in rear lines - cut and diverted lines.
Flushed cooling system changed coolant.
Cleaned out heater core.
Changed thermostat (twice)
Burped system - 6 times
(Raised T&C on ramps - heat on max run for 20 to 30 mins filling coolant as needed till full)
Changed relay - fans come on

What next? What else could it be? Hoping not head gasket. No symptoms of that. I have not done a pressure test done yet, am doing it today.

 

If your coolant rad. core has got corroded (common with aluminium cores) it can't be flushed. Only the old brass/copper types can be flushed, and then there's no guarantee. I've had to cut the brass top with tinsnips to lever it back so I could stuff a thin welding rod down the tubes to shift the crud, Then there is the soldering back...

With ally-core rads., the antifreee is special in that it has corrosion inhibitors to stop ally. corrosion. But the inhibitors only last just so long. With HOAT type antifreeze, about 5 years is the limit. Chrysler tell you in the owners manual about the antifreeze and changing it.

If your ally rad. IS plugged, there only one thing to do -- change it. You can test it by undoing top and bottom hoses, wiping the top hose, and blowing down it vigorously with your mouth. There should be little resistance to this. If it feels a bit like blowing up a balloon, with resistance, it's plugged. Testing this way saves you pulling out the rad. on spec. -- a pig of a job. Another giveaway for a plugged rad. when you get it out is a very slight "curve" along the top, which should be dead straight. -- Tip from a manufacturer here in Leeds.

If there has been over heating due to a plugged rad., it's almost certain the thermostat is also buggered by being jammed open -- it's designed to do this for safety's sake. Best do it while changing the rad., as it's also a pig of a job. And expensive. Changing a thermostat, pay BIG attention to the sealing -- one member here had to do the job twice due to leaks after a while.

All this aggravation starts when the HOAT antifreeze isn't changed when it should be.

If the rad. proves to be ok with the breath test, the other possibility is a damaged head gasket which is blowing high-pressure exhaust gasses into the coolant passages, thereby overpressurizing the coolant system and blowing the coolant out down the overflow -- another very common condition. Tying a poly bag to the over flow pipe with a zip tie or elastic band will catch any coolant while driving, thusly proving where it's going -- and what's causing it.
Fingers crossed it's the rad. That's a lot easier to do than a head gasket which is a double pig of a job.

Leedsman.

 

hi ,would try the chemical head gasket test on the expansion tank, special indicator fluid is used which is blue ,you poor this into a glass vial with a bulb on top, pump the bulb if the indicator fluid changes from blue to yellow,this is a sign that combustion gasses are present in the cooling sys, which normally means cracked head or head gasket failure.
mine tool/fluid is made by mac tools , you can get them from snap on , which should be easy to get hold off in the states.
regards Richard.

 

Simple coolant leak check here that you don't think of...Auxiliary heater exhaust pipe. Inner heat exchanger fractured.

 

Thanks I will try the plastic bag trick first. One thing I forgot to mention I did replace the radiator about 8 months ago, also.

 

My 01 t&c suddenly started overheating and there doesn't seem to be any leaks amd there's plenty of antifreeze in reservoir is plenty full. If I keep it around 30 or 35 mph it cools some. Do 60 and that needs goes to high in a few short min. Not sure what is causing this. Do I change the thermostat and see what happens or any advice would be much appreciated.

 

The radiator may be the problem; it does not seem to be able to effectively remove the engine heat generated at highway speeds. It could be the radiator is partially clogged or the fins are falling out. Could also be very dirty and not letting sufficient through.