TECH: 1997 Chrysler Concorde 3.5 Overheating Again

I'm trying to figure out why my 1997 Chrysler Concorde keeps
intermittently overheating. The car has a 3.5 V6 and 125K miles. About
10 months ago I was driving on the freeway and I noticed the heater was
not working properly. The air would blow somewhat warm and then start
blowing cold air, and then back to warm air. Suddenly, the heat gauge
went to the "H" red line. I quickly drove off the freeway and stop in a
parking lot to turn off the engine. I tried to add some water to the
system, but the engine would still run hot. I had the car towed back to
my home. The next day I added water/coolant to the cooling system -
poured coolant directly into the engine block via the thermostat
housing and added coolant to the system. I also replaced the
thermostat. This seemed to work, because the car ran normally with no
overheating problems for 9 months...

About a month ago, the same thing happened. Same scenario - heater
wasn't working properly, engine overheated and I drove the car back
home a few miles. I waited about 15 minutes before starting the engine
and driving the car back to my home. I said, "It must be a bad
thermostat." Again, I filled up the engine block and cooling system
with water/coolant, and replaced the thermostat with a "premium"
thermostat. The car ran perfectly for a month.

Today, the same thing happed yet again - heater wasn't working properly
(changing from warm to cold and the heater would turn on and off by
itself), engine overheated, and, in addition, a very noisy valve lifter
chattered away while I was trying to exit the freeway to park the car
in order to turn off the engine. Also, at this point, the car had lost
about half of its engine power and stalled out when I parked the car.
Yet again, I had the car towed back home...

So, it seemed like the car was losing coolant at some point, but there
were never any noticeable leaks anywhere. Also, during the overheating
problems, I could hear a lot of water flushing and gurgling in the
heater core area. As if there was not enough coolant in the system.
Also, I could always smell a slight odor of coolant when I sat in the
car over the last year. I never could smell coolant when I opened the
hood.

I looked under the car to see if anything was happening. I noticed that
the tailpipe resonator was dripping water. There was a 3 inch wet spot
where the resonator joined the tailpipe. So, maybe this is where the
coolant was slowly disappearing to.

Well, I was hoping it would not be a head gasket problem, but that
looks like the issue. Or could it be some other component that I
overlooked - radiator, water pump, hoses??? Many Thanks!

 

I hate to be the bearer of bad news but this is most likely the head
gasket, or what I more lean toward is a cracked head. Dodge has had
this problem for the last 15 years or so. What makes me think it is a
crack is that the coolant is lasting less time each time this happens
which would indicate to me that the crack is worsening each time it
overheats. I had 5 Neons and all of them had head problems. Some were
gaskets and some were cracked heads. I took care of them famously too.
Didn't matter though they still ended up the same way. I hope I am
wrong, but I would definatley examine the oil, and look for traces of
coolant, and run the engine and look for cracks. Hope it works out for
you.

 

Water out of the tailpipe is normal, thats what the cat convertor does, If
you are loosing coolant and that is what it sounds lie the problem is, and
you dont see where it is going it could be the head gasket. BUT remove the
radiator cap and make sure the sealing o-ring does not have any cracks,
missing pieces of rubber and just make sure it seals. If the cap does not
seal you could be loosing coolant this way. This is a common problem for
this year vehicle.

Glenn Beasley
Chrysler Tech

 

a simple pressure test can tell wonders as to were a leak exists