Engine Cooling problem
1999 Dodge Caravan 6 cyl Front Wheel Drive Automatic 120, 00 miles
My van was overheating, I took it in and had my radiator flushed, it was bad they said, and thermostat changed, also had AC recharged. Everything is working, both cooling fans come on, but after a while with AC on, the temp starts to go up. Should the cooling fans turn in opposite directions? I noticed they do. What else could cause this overheat.
In your post you stated your coolant was very dirty,
have you had your coolant flushed on a regular basis prior to this problem? How many miles on are the van?
The fans sound like they are working properly. With everything you have had replaced there is not much left with your cooling system.
You said it over heats when you have the A/C on, does it happen as soon as you turn the A/C on, does it happen while you are drining or when you are at an idle? Are you loosing coolant? Do you notice a gurgling sound or is the coolant bubbling out of the coolant bottle?
Lots of questions I realize but each symptom leads to a different diagnosis. The most common problem with older caravans that cause over heating (with all you have already done) is the head gasket is leaking.
Let me know a little more and I will try to steer you in the right direction.
July, 26, 2009 AT 2:05 AM
I just bought the van used a few months ago. It was overheating and I took it to a mechanic friend of mine.120,000 miles on it, I've only driven it for a day since the repairs, I had the AC on full, I live in AZ where it is 110, it took about 20 minutes for it to run hot, I turned off AC, turned on heat, gauge went back to normal, tomorrow I will drive it some more to narrow it down, I'll do highway with AC off, then on, then city driving. Could it need a new radiator? What would be other symptoms of a bad gasket? Prior to my repairs, I did have to add coolant about once a week, I don't think it was leaking, never saw any leak or on garage floor. I have tried to drive it as sparingly as possible to prevent any furthur damage. If it is the gasket, it is covered under the warranty I got from the used car lot. Thank you.
July, 27, 2009 AT 9:27 PM
If you were having to add coolant, it was going somewhere. Some loss id nornal over extended periods (6 months to a year) do to the water content of the coolant. Having to add coolant on a regular basis in the short period of time does indicate a problem.
Being in AZ is not really a concern in this diagnosis. The majority of vehicle produced by all major manufatures of automobiles are operated in warm temp areas, more concern is given to overheating that cold temps in automotive design.
You could have a plugged (bad) radiator like you ask, this is checked by checking the temp into and out of the radiator. Larger than normal temp between the inlet and output or the radiator. If it is hot before the rad and cooler after. If the radiator is getting hot, it is not the radiator.
Turning the A/C off and turning on the heat adds to the dissipation of heat from the engine. Again not a symptom, just an age old stop gap to try to cool an over heating engine while still trying to operate it.
As far as your extended warranty, read it carfully. Each contract is different, it should state clearly in the policy what is covered and what is not. It's kind of like buying health insurance for your car.
Hope this helps, let me know.
Let me know what you find out.
July, 27, 2009 AT 9:52 PM
I drove it yesterday, sat in driveway for 45 min, AC off, gauge stayed normal, drove city driving, AC off 30 min, normal, got on highway, again AC off, started to run hot within 2 miles, turned on heat, went to normal, got home, ran AC on full in driveway for 30 min, stayed normal, then revved up engine for minute or two, started to run hot.I have noticed that the coolant is not full anymore, should be completely full under radiator cap, right. Do not see any leaking, or any stains on my driveway. After I turn van off, I can hear, sounds like a boiling or gurgling sound coming from the engine I think, definitely not the radiator. Could it possibly be the water pump not 100%, does the water pump pump faster at higher rpms. They just flushed my radiator, but it still could have, say a permanent blockage? As far as the warranty, it says the gasket is covered as long as its not a result of overheating, but can't a bad gasket also cause overheating?