I got a lot of good help in another thread on removing my radiator to do a thorough flush. Thought we had the overheating issue resolved.

The car has been at the body shop for the last few weeks for deer repair. When I drove it home Saturday, it acted fine for about 25 mi, then almost home it overheated again.

The only thing I can say that wasn't quite right was that the heat still wasn't working the way it should. Even at running temperature, and the temp control on hot, the air was pretty cool out of the vents.

That being said - does this sound like a water pump issue? Could it be fine for a while, then crap out, then be okay the next day, etc...? Not seeing any sign of leaking from the pump area. plenty of spewing from the reservoir bottle when it overheats.

Could a heater core issue cause the overheating? or vice-versa? I don't mind replacing the water pump, but don't want to go that far only to still have a problem afterwards.

It's only got 80k miles and we bought it new. The plan was to give it to my daughter when she turns 16 this summer, but I'm about ready to make it someone else's problem. Again - I don't mind tearing into it, but hate to spend the $$ & time without knowing for sure.

So - any expert advice to make a definitive diagnosis??

Thanks in advance -
Steve

 

Sounds like a circulation problem to me. Either the water pump or air trapped in the system. Given the mileage, more likely air. I see no way the heater core could be the cause of your problem. Coolant either flows through it or it doesn't. But, if the coolant isn't circulating, you wouldn't have heat. I would top the coolant off again, making sure to bleed all the air out and try it again before diving into a water pump job. Probably wouldn't hurt to drop a new thermostat in it while the coolant level is low.

 

Thanks Richards. I thought I had bled it pretty well before. I put it on an uphill incline & patiently let the coolant settle while running. It stayed in normal temp range for several 20-25 mile drives, then threw craps at the end of a 25 mile drive on Saturday.

Is there any kind of bleed valve or screw on these things? When I google it I see it referred to, but I'm not seeing anyone verifying that there is one. Articles I'm seeing say that people just vent through the cap the way I did. Is this correct?

Last night I noticed a spark plug tube full of oil, so I guess that's another project. When I went to start it, the gauges & lights went schizo - guessing the battery is about gone. I know better than to ask "what else can go wrong". Had this thing for 11 years without a single problem, now I'd be ashamed to trade it. Only 80k miles.

 

That's strange but, it sounds like you did everything right. Neons don't have a bleed screw. They don't really need one because the cap is the highest point in the cooling system. I usually fill the cooling system while the engine is running and keep the cap off until the thermostat opens and I see the coolant circulating. That way I can be sure all the air trapped behind the thermostat is out. There's supposed be a vent in the thermostat to let the air escape, but I'm a little skeptical about that.

I know how you feel about the Neon. I bought mine new and it was trouble free for 11 years, other than engine mounts and brakes; typical stuff. Then the transmission took a crap at 81K. The paint on all the horizontal surfaces is cracked really bad, but it still runs good. Both of my sons started out driving in it and the wife still likes using it as her work car, because it has about ten thousand door dings, so I guess I shouldn't complain. I think I've gotten my money's worth out of it.

 

the only thing that i've found works to get all the air out is to use the thermostat with the shaker/bleeder ball in it, basically the stock ones had it. I spent a good 2 weeks every night re topping mine off after work and still never full got all the air out. Went back an put the old oem original 14 year old stat back in an wala a few days later no air when I pulled off the filler cap @ the head... when its colder here in texas i put in the hotter stat. lol I sound like a puss but it was a lil cooler this year

 

TMB - that is interesting. When it first overheated, step 1 was to put in a new t-stat. The parts store only had the "failsafe" kind, so i went with that. Of course when it overheated, the stat was ruined. The next one I got was just a standard one. I notice it had a small hole drilled in the outer ring, and like a rivet that sits loosely in the hole - with a little travel room each way. Would you think that setup would vent it the way your OEM unit did? I may still have the original one laying around out in the garage. If so, will have to see if it's like you're describing.

Another thing - I've getting conflicting stories around here. One parts store told me it was fine to switch to a coolant other than the mopar (red/brown) stuff - as long as i did a complete flush & fill. Do you guys agree?

 

yeah thats just like my oem with the rivet in yours will do the same thing... Ive been running autozone coolant in mine for years after my first radiator change make sure the spring side is toward the eng an the rivet is at the topside