Chrysler Sebring 2005 Engine & Cooling System



I recently replaced the radiator itself, because the upper radiator hose blew up on me. I tried eliminating some suspect parts, so I replaced the radiator cap with a fancy valve relief lever, a lower temp 180 DEG F thermostat, new coil wires, new sparkplugs, oil change and new coolant.

I also changed the water pump two years ago. No leaks or drips from the cooling system.

Some of the symptoms are coming back still. Like the temperature would rise above the middle of the temp gauge when I stop and idle at the traffic lights, but it goes back down to middle when I start moving. Although on the freeways, the temp gauge needle floats below the middle line and it looks all normal.

I thought I did eliminated the trapped air, so I am gonna try to fix that once again. Meanwhile, I will check the seal and seating of the thermostat as well.

Slightly off topic, but it could be another related problem: I had the engine mounts replaced (front and back) the car is shaking rough on reverse and when on idle. I didn’t do the mounts. I get an cylinder 4 misfire error code right about the same time I got these shakes. I also get these flickering instrument panel light inside the car once in a while even though I already replaced the main battery cable.

I don’t know if I missed anything, but that’s the update so far.


If you live in a state with smog inspections, you may eventually fail

The reason is this . . .

You installed a thermostat with a lower temperature rating

The engine will not get up to proper operating temperature

that could result in a P0128 fault code, which results in the check engine light being illuminated

check engine light illuminated = smog inspection failure


My car threw a cel due to it running maybe 5 to 10 degrees cooler, judging by the temp gauge so I assume your car does not monitor for a po128 too cool code. The overheating and misfiring may be related.


I wouldn’t count on it


I wish I had that low temperature problem. This thing went past the middle of the temp gauge and nearly blew up on me on idle. I had to put the car on neutral, rev the engine to 2K RPM, so it would run back to middle temp on the gauge. I suspect leak in the circulation, but all are new. I wonder if the cap with that fancy lever is causing the problems, if not the new thermostat.


Are you under the impression that if the coolant gauge is anywhere above the middle, you’ve got a serious problem?

Those gauges aren’t terribly accurate, either. Keep that in mind

If you want a more accurate coolant temperature reading, you need a laser thermometer, or look at the reading on a scan tool

It could be that the gauge reads 2/3, and you think there’s a problem, when in fact the temperature’s right where it should be


That statement tells me you need to have a professional look at this vehicle because this thread is over a year old without a solution.


It may seem counterintuitive, but installing a lower temperature thermostat could cause the engine to overheat. This is especially true if your car sports a bypass-style thermostat. Suggest to install the correct thermostat for the vehicle. When you idle for more than a few minutes, say 5 minutes max, the radiator fans should turn on and spin like crazy. Suggest to verify they are coming on like they should. Once you’ve got the correct thermostat installed and verified the fans are turning when they should, if you still have the overheating or misfire problem, let us know.


I agree, it sounds like your cooling fans are not coming on, try replacing the relay. It would really help if you told us if your car is a 2 door or 4 door and which engine. They were actually different cars under the skin. There were2 different2.4 liter 4 cylinder engines. A Chrysler built for the 4 door and a Mitsubishi built for the 2 doors. There were also Mitsu built 3.5 and 3.0 V6s but I don’t remember which went in which. At least one of them might have used a fan control module also.


This is a Chrysler Sebing 2005 4 CYL 2.4L 4 door.

I think I should put back the old thermostat, which is 190+ DEG F. Fans work just fine, but I think you guys are right I should check on that relay switch, too.

Unfortunately, I found out what the real problem is on this car now. It overheats at idle, it goes back down when the car is moving. The water pump stopped working! It was probably leaking slow already, but I didn’t see the heavy flow until last night. This time it hit the MAX, so I quickly pulled off the freeway. I had it towed home.

Working ion it now. I’m gonna use the Gates 41006 water pump. It took me two weeks to work my way into the water pump last time. Hopefully, I can get to it sooner, except the weather here is too warm. Also a good idea to fix the timing since it’s shaking rough.


Can you further clarify “stopped working” . . . ?

Do you mean the water pump is leaking?

Do you mean the water pump’s impellers are broken off, not spinning, not flowing enough coolant, etc.?


If your water pump is leaking it needs to be replaced and any leaks can cause overheating from low coolant but I don’t see how a bad water pump can cause overheating only at idle.
That is usually caused by non working fans. If your fans are working fine, why would you replace the relay?
I hpoe that when you replace the water pump it solves all your problems but I think you have not discovered the root of the problem.
And yes, put a 195 degree thermostat back in.


New pump because it leaked; new radiator, because it was clogged; flushed the heater core, no clog.* I thought the engine was making all those noise, I could’ve reduced the noise level with new pulley/tensioners. I could actually replace these enclosed bearings in the pulley myself, but it’s too much trouble and I don’t have a pusher to uninstall and install new ones in. Anyway, next time.

No problem with radiator fans, I can still hear two speeds between high and medium.

I noticed some electrical issues like the vent inside the dashboard. So, when I switch back and forth between defogger and other vents it would have some significant delay. I think there’s a short somewhere, too. Some other times the defogger vent works when I select a different vent.

Later, I smelled coolant through the vents. Yes, I also lost heat from the air vents, but this all happened after I replaced the leaky water pump, the clogged radiator and flushed the heater core.

I found out Chrysler put in this drain hose just above the powersteering hose assembly below where the passenger’s left foot would be. The heater core*, which I now know is leaking, is encased in a plastic case along with the A/C’s evaporator/radiator. This video is not a Chrysler, but same issue and this guy is excellent, [].

Replacing the heater core is suppose to be six hours for a professional mechanic. Automotive mechanics and electrical automotive was YEARS ago, so I’m neither a pro nor a mechanic. No shade where I am parked, too, so slow going at this time. Thanks to everyone who helped! I will post some photos and questions here in the future,

2005 Chrysler Sebring 4 CYL DOHC 4 DOOR.
Short link to this photo album |
I have more questions posted at


Keep on keeping on. Good for you. Sounds like you’ve made significant progress. Best of luck, and yes, keep us informed.


The real problem was HEAD GASKET, it leaked. We took the head for machine shop work at EngineShopAndParts.Com (Sun Valley, CA). Leak down test using water and not just air. Used Honda Bond for seal. Problem solved.

Sorry for the late reply.