Chrysler 300 - The Saga Continues

[J. Morgan]

Perhaps a Hemi radiator might work?

IDK if the hose ports, cooler ports etc are in the right place, but maybe.

[mstephens]

Originally Posted by HiHoAgRV

From my experience a thermostat that goes from antifreeze to water will almost always stick. There is your problem.

I just hope I can get the dealer to replace it. I have full warranty for another 1600 miles.

One of the reasons I am convinced it is a sticking t-stat is the erratic behavior. On the way back - on level road at 30mph - it would stay at 250F the suddenly drop to 220F for maybe 4 minutes, then quickly rise again to 255F.

If I pull over and STOP when it is 250F and simply idle the motor it should drop within minutes to normal temp of 210F. It doesn't. The fan runs, the temp stays at 240F/250F for a long time. That's not right. If I turn it off for say 30 minutes, it will come down to 220F.

[mstephens]

Originally Posted by J. Morgan

Perhaps a Hemi radiator might work?

IDK if the hose ports, cooler ports etc are in the right place, but maybe.

Well, I keep coming back to the experience of Andy. He has several of these and other Pentastar V6 TVs running around, and from the sound of it, they have tens or hundreds of thousands of hours on them with no heating issues. He even told me there is one in Arizona who ran all summer long towing in the desert heat with no trouble. I am therefore leaning that something is wrong with THIS car. Although, my patience and confidence is near an end.

[J. Morgan]

Don't give in, you can't let the car win...

Be patient and work through it.

[J. Morgan]

It kind of does sound like a t-stat or something, it should cool when not under load.

[TinTin]

Surprising that the dealer didn't replace the thermostat when you were last in. Probably a 40 dollar part and a half hour labour.

[wkerfoot]

mstephens,

We you driving around north Palm Springs about 11 this morning?

We saw a white 300 towing a wide body Airstream on our way to the Vintage Trailer Show.

Bill

[mstephens]

Yes, that was us. I am pretty sure there are no other C300 TVs nearby. We limped it home slowly and then went to the antique trailer show after lunch.

[xrvr]

Get the system flushed, new tstat and insist on a full test drive by tech if at all possible. Has to be something with this particular car. Any service records available from the selling dealer? Warranty work should be documented by Chrysler. Good luck. Jim

[Buck944]

I would go back to your dealer and pay them to remove the thermostat and put new coolant liquid in. I think that a lot of question will be answer running the car in that condition...

Don't give up!!

[dznf0g]

When it is hot, have you looked under the hood to see if there are any bubbles appearing in the surge tank? I still feel like there are combustion gasses escaping from the combustion chambers into the cooling system. Is the level in the surge tank dropping at all after an overheat cycle, when it is completely cooled down?

[mstephens]

Originally Posted by dznf0g

When it is hot, have you looked under the hood to see if there are any bubbles appearing in the surge tank? I still feel like there are combustion gasses escaping from the combustion chambers into the cooling system. Is the level in the surge tank dropping at all after an overheat cycle, when it is completely cooled down?

Yesterday it did not appear that ANY coolant was being lost. I looked very closely everywhere under the hood while running. Coolant level is on the HOT mark. Slight gurgling sound from the reservoir. This am I will check the COLD level. I marked it carefully before we left yesterday.

If the dealer won't change the t-stat under warranty, I'll go to my mechanic and pay to have him do it.

You know, in a modern dealer service situation you can't get to the mechanic. A "service writer" intercepts you to do paper work and they have no car knowledge. It's hard to get across the fine points of what the car is doing. So, I am going to type up a description that can be handed to the mechanic. Otherwise, the service writer puts down "over heating" and the mechanic does a basic test and if it doesn't show a problem, he's done.

[dznf0g]

The gurgling makes me believe there are gasses in the cooling system. So does the very rapid rise in coolant temp...form hot to very hot in short time described above. It's a long distance, sight unseen diagnosis, but I really think it's a head gasket or cracked head/block. You should see some lowering of cold coolant level though....and smell coolant at the exhaust.

[Bill M.]

At the very least I would change the thermostat and the radiator hoses. I have had a hose that would collapse at intervals.

Are you running an add on transmission cooler?

I would also look at getting rid of it unless I found a clear, definitive cause and could assure it is fixed. My experience was you could run around town and idle it in parking lots at 100 degrees and it was fine. But drive it on the interstate and stop for a rest area or gas and it overheated and spewed fluid everywhere. But not everytime.

[GCinSC2]

Rich,

Aren't there shop tests for combustion gases in the coolant?

Jut did a QUICK search and this Autozone info Product & HowTo Info | | | INSPECT | AutoZone.com came up, scroll down the page a bit. Might offer a little insight.

Gary

[dznf0g]

Yes, but I wouldn't assume they did it...or properly. I have seen instances where a head gasket seals pretty well cold and opens up hot. Didn't show on a couple hour cold pressure test. Might show overnight.

Sent from my XT907 using Airstream Forums mobile app

[xrvr]

Man, what a pain in the butt. Document everything and like I said the service dept. should be able to pull up all warranty work done by vin number no matter what dealer did the work. Past history could be your salvation if the worst case scenario comes true. Jim

[mstephens]

New Info

I checked the levels. It was down about 1 Qt of coolant.

I plugged in my ODBII reader, started the car and immediately got this message:

P0117 - Engine Coolant Temperature Circuit Low Input

[Bob4x4]

28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM), 3.6L/Diagnosis and Testing
P0117-ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT LOW
For a complete wiring diagram, refer to the Wiring Information.








Theory of Operation

The Coolant Temperature Sensor is a variable resistor that functions as a normal two wire 5-volt sensor. The PCM supplies a 5-volt reference on the signal circuit, and a ground to the sensors low reference circuit.




When Monitored:
With the ignition on. Battery voltage greater than 10.4 Volts.

Set Condition:
The Powertrain Control Module (PCM) detects that the Engine Coolant Temperature Sensor input voltage is below the minimum acceptable value. One Trip Fault. Three good trips to clear the MIL. If the vehicle is equipped with the stop/start feature, the system will be disabled when this DTC is active.


Possible Causes
ECT SIGNAL CIRCUIT SHORTED TO GROUND
ECT SIGNAL CIRCUIT SHORTED TO THE SENSOR GROUND CIRCUIT
ENGINE COOLANT TEMPERATURE (ECT) SENSOR
POWERTRAIN CONTROL MODULE (PCM)


Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).




1.ACTIVE DTC


--------------------------------------------------------------------------------


NOTE: Diagnose and repair any system voltage DTCs before continuing with this test.
1. Turn the ignition on.
2. With the scan tool, select View DTCs.


Is the DTC Active at this time?

Yes

Go To 2

No

Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).



2.ECT SENSOR


--------------------------------------------------------------------------------
1. Turn the ignition off.
2. Disconnect the ECT Sensor harness connector.
3. Ignition on, engine not running.
4. With the scan tool, read the ECT Sensor voltage.


NOTE: The sensor voltage should be approximately 5.0 volts (plus or minus 0.1 volts) with the connector disconnected.


Does the scan tool display the voltage as described above?

Yes

Verify that there is good pin to terminal contact in the ECT Sensor and Powertrain Control Module connectors. If OK, replace the ECT Sensor. (Refer to 07 - Cooling/Engine/SENSOR, Coolant Temperature - Removal) .
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

No

Go To 3



3.CHECK FOR THE (K2) ECT SIGNAL CIRCUIT SHORTED TO THE (K915) SENSOR GROUND CIRCUIT


--------------------------------------------------------------------------------


1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Measure the resistance between the (K915) Sensor ground circuit and the (K2) ECT Signal circuit in the ECT Sensor harness connector.


Is the resistance below 5.0 Ohms?

Yes

Repair the short to between the (K915) Sensor ground circuit and the (K2) ECT Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

No

Go To 4



4.CHECK THE (K2) ECT SIGNAL CIRCUIT FOR A SHORT TO GROUND


--------------------------------------------------------------------------------


1. Measure the resistance between ground and the (K2) ECT Signal circuit in the ECT Sensor harness connector.


Is the resistance above 10k Ohms?

Yes

Go To 5

No

Repair the short to ground in the (K2) ECT Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).



5.POWERTRAIN CONTROL MODULE (PCM)


--------------------------------------------------------------------------------
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the ECT Sensor and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the ECT Sensor and Powertrain Control Module connectors.
4. Perform any Technical Service Bulletins that may apply.


Were there any problems found?

Yes

Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

No

Replace and program the Powertrain Control Module in accordance with the Service Information. (Refer to 08 - Electrical/8E - Electronic Control Modules/MODULE, Powertrain Control - Removal) .
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

[J. Morgan]

Could be a problem. Maybe the fans are not getting the signal to come on or to move to high speed.

Chrysler uses fans with a high and low with separate relays for each speed.

When the engine is hot both fans should be at high speed. This should be audibly noticeable.