Mechanic help?

[kcinnick]

My wife got a 2003 dodge neon when she graduated and I was planning on trading it in tomorrow, however it has developed a worsening overheating problem.

So the first thing I did was check the radiator cap, it was worn so it was replaced. The system holds pressure.

Second I checked the thermostat, it looked like it was working, but since it was open, whats $7.99 to just replace it.

Then I flushed the radiator and put in new fluid. There is no purge valve, but the system seems to purge itself when it runs. I ran it up to temp a couple of times and each time it needed to be topped off, a little less each time until there was no need to add any coolant.

The water pump is circulating coolant.

The fans kick on after a couple minutes.

The kicker now is the car could be driven for 20-30 minutes before overheating, how it just takes 10 minutes!!!!

Any ideas?

 

[Suburbazine]

Losing coolant, overheating, takes run-time to achieve = bad head gasket most likely.

Does it only overheat when sitting still, or does it overheat on the interstate too?

 

[bs875]

Losing coolant, overheating, takes run-time to achieve = bad head gasket most likely.

Does it only overheat when sitting still, or does it overheat on the interstate too?

I'm not sure he said it was losing coolant, only that he was topping it off as it circulated.

There may be a blockage in the coolant passages. I would try removing the thermostat entirely and see what happens. If there is a blockage that is restricting flow somewhere removing the thermostat will open up the flow overall.

 

[shoalsfugro]

Any white smoke out of exhaust? leaks?

 

[kcinnick]

It is not losing coolant.

I hope its not a blown head gasket, I wanted to trade this thing in tomorrow.

I will try running it without a thermostat and see if that helps anything.

Flow is pretty vigorous at operating temp though, how much flow should I expect?

Yesterday it idled for nearly an hour without overheating, today it lasts about 10 minutes. Driving makes it worse at any speed. I don't want to go too far as I don't want it to get too hot too long while I figure this out.

No white smoke.

 

[LACamper]

How's the oil look? milky?

 

[dantheman]

Radiator hose collapsing ?

 

[kcinnick]

I changed the oil today and it was a little milky, I just thought it was from short trips. My wife often makes short trips.

 

[El Rubio]

I just changed the water pump on my old pickup. Sounds just like your description. I saw water seeping from the weep hole on the pump. About a month ago, I had a leaking freeze out plug that I had to replace. It was also obvious upon close inspection since it was a leak. When I replaced the pump, I went ahead and replaced the thermostat and both radiator hoses as well as flushed the coolant. Good luck with it.

 

[kcinnick]

Ok, I just googled milky oil and her oil was nowhere near what her oil looked like. I would rate the images on google search a 9/10 milky and hers 1/10 milky.

 

[Jimmy Dean]

it is likely some blockages inside the radiator itself. decreasing flow through certain parts of it, but not overall.

 

[Yrdawg]

what kind of fan does it use ?? We ahve a 02 neon, but I couldn't remember the fan

Is it electric, clutch ???

 

[smith625]

Thermostat seems likely by the elapsed time to overheat now.

 

[paddle007]

Long shot

Some of our cars have cooling systems which can be a PITA to bleed. Just to make sure your not having issues with air try this. Park the car with the front bumper as high as possible, use a bumper jack if you need to. Remove the radiator cap and run the engine about 1500 rpms for 10 minutes. Add coolant as necessary. BE VERY CAREFUL and never put your body in a direct line of fire of the radiator cap. Look at where the geysor would hit the hood and predict where you might safely stand and add coolant.

If the waterpump were not timing belt driven I would suggest you remove the thermostat, remove the waterpump drive belt, fill the cooling system then run the engine and watch for gas bubbles rising to the top. That is a positve test for a blown headgasket. FWIW Neons do have a fragile headgasket. Goodluck with it.

 

[herohog]

Good circulation shows the t-stat is open. The fact that driving it doesn't cool it down eliminates the fan(s) as the issue. No fluid loss/no white smoke/no milky oil eliminated head gasket. If the radiator hose collapsed there would not be good flow observed in the radiator.

The only thing that makes sense to me is an obstruction in the block somewhere. Flushing the radiator may have shifted the sediment increasing the blockage making it worse. I would Power-flush it, in reverse as well as in the normal direction. Kits are available at your local parts house for doing this at home using your garden hose. Use a cooling system cleaner before the flush as well.

 

[dantheman]

Whatever it turns out to be , let us know . We're curious folks .

 

[kcinnick]

Ok, So the car does fine getting up to temp, drives better than it ever has (I replaced the motor mounts and did an oil change before trade in, the rattles were really reduced). From the time it reaches operating temp to overheating is about 2 minutes, maybe less. Driving or idle. The overflow chamber is bubbling at this point, but it doesn't seem to be boiling.

I honestly don't think the head gasket is blown at this point and I don't want to blow it trying to get the car working.

Paddle007,

Would driving the car on ramps be too much incline? The car idles at 800 rpm, is that enough to bleed the air?

I filled the radiator from the hose connected to the thermostat when I filled it up, I also filled the overflow chamber until coolant ran to where the radiator cap goes.

 

[kcinnick]

New symptom, heater does not work. I did not notice it earlier due to the 105 degree weather, but last time I tried when it was a cool 80 degrees outside it was noticeable that the heater does not work.

The overflow chamber starts bubbling well before the car gets hot, I think there has to be air trapped somewhere.

I drove the car up on a 2x4 to get the front end higher, ran the car and added coolant when the system "burped". It burped once for sure and I needed to add a decent amount of coolant, the second "burp" may have been just the level dropped enough to need me to add some from sloshing out. Coolant is moving through the system I just don't know what to do next. They need to integrate the cooling system into the CEL system.

Wife got a code, misfire Cylinder one, pulled the plugs, plug was fouled, changed plugs, GTG.

Wife got a code, emission leak area XXXX, basically between to sensors. Found vacuum line between the sensors, found leak, replace line, GTG.

Car overheats, and Cluster****.

 

[herohog]

The heater not working is another sign of a blockage in the system.

 

[11Bravo]

My heater coil rusted out and I had same symptoms. I know nothing about cars, so I don't know if you have one of those or not, but something to look into.