Need coolant advice

[phanatic32212]

I hope no one gets mad at me since this is not a truck question, but this is beginning to worry me and I know you all have alot more knowledge than me. So, here goes:
I have a 1999 Chrysler Sebring 6cyl. The engine has been running very hot lately. If I sit at a stop light or in traffic for more than about 30 seconds, the temp guage jumps to almost overheating, BUT if I turn on the heater while all of this is happening, nothing but cold air. As soon as I start moving the heater blows air hot enough to bake bread and the temp goes back down. I don't have any rough idle. The car runs fine except for that. I don't have any leaks and there is plenty of coolant.

Thanks for any insight.
Jake

[67chevemall]

Don't buy vehicles with computers!
Later

[whitesswj]

sounds like your thermostat is stuck closed or maybe the radatatior is stopped up.

as you know when you turn the heat on the heater core acts as a radator that's why i'm going to lean more toward the rad clogged!

my .02 sswj

[phanatic32212]

thanks thats what I was thinking but I think I will try a thermostat first. It'll be a little less expensive for trial and error.
Thanks Again

[Fred T]

Before buying a new stat, check it. First, warm up the engine with the radiator cap loose so it doesn't pressurize. Watch the coolant and see if it's flowing. I don't know what temp yours is, I would guess 190. You can also stick a meat thermometer in the coolant to check the temp. If there isn't any flow, you either have a bad stat or temp sending unit.

To check the stat out of the vehicle, suspend it in a pan of water on the stove. The stat should not be touching the pan so the heat only transfers through the water. The stat should have it's opening temp stamped on it. You can use a thermometer to check the temp for opening and closing. If you don't have a thermometer to use, just heat the water to boiling. If it hasn't opened by then, it's bad.

[rustyold72]

If this was a GM car I'd say the Dex cool had turned to jelly, does Chysler have an equivalent to Dex cool?
How are you checking the coolant level, looking at the plastic resevoir, or opening the radiator cap and looking in the radiator.
Check the radiator and see if the coolant has turned to jelly (happens on GM cars with dexcool)

[70c10]

Make sure your fans are working!. They are known for having the fan switch go bad.

[Hoods69BadBowTie]

I was just goind to suggest checking your fans to see if they are working, other then that it sounds like a clogged rad but good idea deciding to go get a new thermostat first.
Post up if you have more problems.
-Later

[phantom dually]

My vote is to get it fixed and SELL IT NOW!! Damn DODGE

[72k5]

I don't have anything to add that is model specific, but the problem you're having sounds like it might be air in the cooling system. You might check the manual for the coolant drain and fill procedure to see if it mentions anything about a bleed valve, or needing to remove a hose, etc. A little burp may save you a lot of work and messing around if it turns out to be the problem.

[dwaite72lnghrn]

Sounds like coolant level in the system is low. If it were the Tstat he would still get heat out of heater ( most heaters go around the Tstat). The other choice is a bad water pump, corroded or broken impeler. Once the revs climb the pump moves fluid.

[phanatic32212]

thanks for all of the ideas. I had a pressure check done and it is good. The fans are running, I just thought I would get a "second opinion." The mechanic told me I need a new radiator. Should I just go with the chemical flush and thermostat before I go and pay for a new radiator. Seems like the reasonable thing to me? Just trying to spend the least amount of money. I new buying this thing was a bad idea, but the wife...well you know. lol
Thanks
Jake

[whitesswj]

Originally Posted by phanatic32212

thanks for all of the ideas. I had a pressure check done and it is good.
mechanic told me I need a new radiator.

why would he say that if the psi ck is good?? hmmmmm

Originally Posted by phanatic32212

Should I just go with the chemical flush and thermostat before I go and pay for a new radiator. Seems like the reasonable thing to me?
Jake

I would as it sounds to me as if you just need a good clean boil out and if you take it to a rad shop they sometimes ck it off the car and if it is bad after the boil and fix then they just sell you the rad and forget about the boil and fix
i had a rad fixed w/ 6 holes in it and they charged me 58 bucks for it. think about it 58 vs. 175 for anther 3 core rad. hmmmm

my .02 sswj

[curbyk]

I agree with dwaite72lnghrn low coolant will cause this to happen, check this first. Look in the radiator and not just the the holding tank.

[72k5]

Unless you are on good enough terms with your mechanic that he bears all the risk on this diagnosis, I would go carefully here. I have a really tough time believing that the radiatior is plugged up and causing your problems. The symptoms you describe are those of low coolant or air locks. You should not get an intermittent heater problem unless your engine is getting hot enough to boil some of the coolant out first, then you get the problem you describe from the low level or steam pockets. I fully admit that I am not very familiar with the design of the cooling system on your car, and some do have their own special issues (usually hinted at in the owner's manual), but I did my time as a tech, so I have been down this road many times.

If the rad fans are working, and they are, a plugged radiator will usually show up first as an overheating problem when you have a good load on the engine. It will usually get hot in a situation where you have a large load on the engine - uphill, or shortly after accelerating to freeway speeds.

I would first try to make sure the cooling system is really full. Starting with a cold engine, take off the cap, start it up and put the heater on low. Hopefully you can idle it until the thermostat opens without it belching out too much coolant. Then, top it off once the coolant is circulating.

If the heater works fine, and it doesn't overheat if you confine your driving to low speed streets, then, it only acts up when you slow down after you do some high speed or load driving, I would be more inclined to suspect the radiator. Your reservoir bottle should be overfull from the coolant that boiled out of the system at that time.

Hopefully this will give you some ideas.

Also, since you are in CA, if you decide you need radiator work, it is probably more cost effective to just replace the radiator. Labor rates are so high here that the repair usually doesn't make sense.

If fact, if you do it yourself, it may actually be less total dollars than having someone repair the one you have. Hold out for a Modine, AC Delco, Harrison, or something that someone with model specific experience (not a radiator company) guarantees will fit perfectly. I have had trouble with fit and sometimes quality with all the import replacements, as well as the US made Visteons.

I hope something here helps you out.
Mike