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I bought a used 2002 neon about a month ago, around 80k miles, was doing great. One day i was going down the highway around 75-80 with the A/C running and it started overheating! I shut the air off, pulled over and let it cool, drove it home with no AC on, and it ran just fine. I flushed the cooling system (old fluid looked like they had just kept adding to it and never changed it for scheduled maintenance ) and filled it back up! Took all the precautions of burping it and getting the air out. Haven't lost a drop since then, which was about a week ago. It does fine with the A/C when i drive to work (about 15 miles, 65-70 the whole way) both in the morning and the blazing sun in the evening on the way home. But when i take it out on the interstate and am running the A/C g going 75+ it likes to over heat! Any ideas? Thermostat? Fluid temp sensor? Air pocket?

Before the first time it overheated it ran just below or right at the lower 1/3 mark on the water temp gauge, ever since it's ran right at the 1/3 or just a hair above it... Just a little frustrating...

It may be a good time to change the thermostat and radiator cap along with the radiator hoses. As hoses get older they become soft and actually collapse reducing the water flow. One thing that concerns me though is what you said about the color of the antifreeze. The rad core could be partially plugged causing the engine to heat soak due to slow water transfer. Another thing I would ask is how long has it been since the water pump was changed? This also could be contributing factor. The impeller in the pump of my 2000 ES was partially worn away when I changed it at 87,000 mi. Unusual yes, but it does happen. Check that the a/c fan is running at the proper speed too. Have the rad checked first at a radiator shop would be the first suggestion. Just a process of elimination. Check the obvious then go from there. If you replace the water pump it would be THE time to change the timing belt too. Could save your engine down the road.

I have seen topics about 195/180 degree thermostats, but i also see there are 160 degree thermostats available... would one of these be worth getting?

No.

The 160º t'stat won't help your problem, unless it is not opening all the way. But most are fail safe, in that they will fail at full open. Nothing is guaranteed tho. I am going to agree with g_force58 on this one.

I wouldn't go less than 180º, but would stick with what it came with, to retain the proper fuel trims. You aren't going to see any better power from running a cooler t'stat.

The only part that is off, is the cooling fan will generally not run above a certain speed, as there is more air flowing through the radiator than the fan can pull, so it is shut down, to reduce drag from the alternator.

But the PCM cannot know if the coolant is flowing correctly, or if there is debris blocking the radiator.

For all new hoses, you are going to have about $50. Advance will have the upper and lower hoses. I just went through this. AutoZone did not have both in stock, and they were higher cost, for a cut to fit lower hose.
Mopar does not sell them anymore, according to my dealer. The heater hoses are the only thing they can get. Don't forget the hoses beneath the IM.

The numbers you need are:
E72126 $11.99 Upper
D71995 $16.99 Lower

Goodyear # 93925 for the two under the intake manifold. It will need to be cut in two pieces to work.

I can understand/agree with that.

I think I'm just going to install all new hoses, thermostat, water pump, and a new radiator (just to be on the safe side regardless, this one's fins are pretty dinged from bugs, pebbles, etc...). It'll give me a weekend project anyway!



The only issue I have is with replacing the timing belt. I helped a friend do one on a 1st gen about 5 years ago and I remember it being kind of a pita... any suggestions?

The timing belt does suck, ive done it twice in 5 months... Once you do it a few times, you get the hang of it.

If you have the money to spend, then buy a new radiator, but IMO I would just change the hoses, thermostat, and cap and see how it goes from there.

Always do the cheap/easy stuff first. But if you are due for a new timingbelt, then change the waterpump while you are down there.

Yeah maybe I'll just try the cheaper options first and work my way up if the problem persists.

I bought the car with 81k on it, so I would imagine it's due for a timing belt change, since I don't know and doubt it has been changed, regardless of the issue I'm having so i was just going to swap the water pump as well.

I thought of something else. Do you have an ATX? (Those hose numbers are for mtx, BTW)

If the TC is not locking up, or the trans is overheating for some reason, it will cause an issue similar to what you are having.

Sorry to add another potential problem to the list. If you are MTX, then nevermind.

Yeah I have an MTX... wouldn't want it any other way!

I got a new thermostat earlier, gotta pick up hoses in about an hour and a half... so I guess we'll see how that goes! If not, back to the drawing board! lol

In my first reply I was not clear about some things, but thankfully OD and others picked it up and pointed you in the right direction. Thanks guys! OD, thank you for teaching me something. Didn't know the fan cut off when there was enough airflow and that is good to know. I meant to say as OD, did that you should take the cheaper things first, then if needed to go from there. My apology if I confused you. Forgot that not everyone has the same troubleshooting experience and I will be more careful in the future. The are many good and knowledgeable people on this forum, use their tips, tricks and knowledge. I have, but I don't know everything. This board is a great resource and a wonderful community. Rick

Well i think my car did me a solid as far as letting me know exactly what's wrong!

I went out this morning and jacked it up to change the hoses, thermostat, etc and the underside of my engine on the passenger side was wet with a small bead of antifreeze hanging off. i found no leaks from any hoses, the radiator, connection to the thermostat housing so i'm 99.9% sure it's the water pump that's bad and needs replaced!

Would i be correct in my assumption? I'm pretty sure!

Seems likely. Definitely the best place to start, and if you see something that looks off, post it up and I'm sure these guys can get you squared away.

It would either be the weep hole for the WP seals, or the hoses that connect to the head and WP to the heater tubes.

There is also the possibility of the rear WP tube leaking where it goes into the back of the pump.

The T'stat housing where it mates to the head, but that would be relatively easy to see.