Overheating issue

Tiny
MARK4613
  • MEMBER
  • 1999 DODGE CARAVAN
Engine Cooling problem 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. What else could cause this overheat?

Please help me, I love the site
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Saturday, July 25th, 2009 AT 6:26 PM

57 Replies

Tiny
DANAUTHIER
  • MECHANIC
  • 156 POSTS
It sounds like you have blown head gasket which is common on these cars. To confirm the problem please follow this guide.

https://www.2carpros.com/articles/head-gasket-blown-test

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 driving 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.

Here are some guides that should help as well

https://www.2carpros.com/articles/engine-overheating-or-running-hot

and

https://www.2carpros.com/articles/symptoms-of-an-overheating-engine

Please let us know what you find.

Cheers
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Saturday, July 25th, 2009 AT 9:51 PM
Tiny
MARK4613
  • MEMBER
  • 6 POSTS
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.
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Sunday, July 26th, 2009 AT 2:05 AM
Tiny
DANAUTHIER
  • MECHANIC
  • 156 POSTS
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.

This guide can help you

https://www.2carpros.com/articles/coolantantifreeze-in-the-engine-oil

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.

Hope this helps, let me know...

Let me know what you find out.
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Monday, July 27th, 2009 AT 9:27 PM
Tiny
MARK4613
  • MEMBER
  • 6 POSTS
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.

So I did the test on the head gasket and to was positive it turned the test liquid yellow now I need to see if I want to fix it or trade it in!
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Monday, July 27th, 2009 AT 9:52 PM
Tiny
FOOTBALLMOM
  • MEMBER
  • 2 POSTS
  • 1999 DODGE CARAVAN
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 130,000 MILES
Engine Cooling problem
1999 Dodge Caravan 6 cyl Two Wheel Drive Automatic 130000 miles

Hi -
We have been having issues with the van overheating. The check engine light went on a while ago got that checked out and was told it was the relay switch, replaced that didn't help. We have now replaced the temp. Sensor and the fuse. The van still over heats. The thermostat is only about a year old or so. We have had the fans checked and they do work they just for some reason will not turn on. The air conditioning will work but it makes the van get hot too fast so we don't dare run it. We can drive for hours and the van is fine, it is just when sitting for too long.
Any suggestions?
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Friday, May 26th, 2017 AT 7:00 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Could be the thermostat again, engine temperature sending unit/switch, fan relay, failing water pump and clogged radiator
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Friday, May 26th, 2017 AT 7:00 PM (Merged)
Tiny
FOOTBALLMOM
  • MEMBER
  • 2 POSTS
Thanks for your reply. I have called a few auto stores looking for the engine temp sending unit but no one has it for our van. Can you tell me where it is and what it does?
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Friday, May 26th, 2017 AT 7:00 PM (Merged)
Tiny
PUMPER
  • MEMBER
  • 2 POSTS
  • 1999 DODGE CARAVAN
Engine Cooling problem 6 cyl Front Wheel Drive Automatic 158, 00 miles

I have a recurring problem with overheating, on & off. Mechanic says thermostat is OK. What gives?
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Friday, May 26th, 2017 AT 7:00 PM (Merged)
Tiny
DOCFIXIT
  • MECHANIC
  • 18,828 POSTS
Cooling fans operating at time of overheating?
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Friday, May 26th, 2017 AT 7:00 PM (Merged)
Tiny
PUMPER
  • MEMBER
  • 2 POSTS
Yes, blower was on but not a/c
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Friday, May 26th, 2017 AT 7:00 PM (Merged)
Tiny
DOCFIXIT
  • MECHANIC
  • 18,828 POSTS
Cooling fans underhood behind radiator
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Friday, May 26th, 2017 AT 7:00 PM (Merged)
Tiny
KOHLLINK
  • MEMBER
  • 80 POSTS
  • 1999 DODGE CARAVAN
  • 130,000 MILES
After the van warms up(about 2 miles) the temp gauge starts to get close to pegging the hot line. Replaced the thermostat and water pump. Still acting the same. I haven't seen any milky oil yet. Not blowing any white exhaust yet. I see some bubbles when the radiator cap is off when I'm checking the antifreeze. I guess my question is does head gasket sealers work?
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Friday, May 26th, 2017 AT 7:00 PM (Merged)
Tiny
JOHNSGARAGE99
  • MEMBER
  • 8 POSTS
O.K. First a few simple ideas. Have you cleaned the radiator out? Take the upper and lower hoses off and flush water thru the radiator. Then take a hose and flush thru the radiator to clear out bugs and road debris. You are using a 50/50 mix of good antifreeze? See if your local auto parts store has a cooling system pressure tester. Put that on where your radiator cap goes, start the van and watch the gauge as the van warms up.
If it climbs over 17 lbs you may have a head gasket issue.
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Friday, May 26th, 2017 AT 7:00 PM (Merged)
Tiny
FIXITMR
  • MECHANIC
  • 9,990 POSTS
If pressure test fails head gasket sealer may fix it. Cheaper than engine dis-assembly.
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Friday, May 26th, 2017 AT 7:00 PM (Merged)
Tiny
KOHLLINK
  • MEMBER
  • 80 POSTS
Regrouped could this be a bad cooling fan relay? The fans work when in park or at a low rpm. Could fan speed be a problem at higher speeds with the a/c on?
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Friday, May 26th, 2017 AT 7:00 PM (Merged)
Tiny
FIXITMR
  • MECHANIC
  • 9,990 POSTS
Fans need to be on high speed with air on.
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Friday, May 26th, 2017 AT 7:00 PM (Merged)
Tiny
KOHLLINK
  • MEMBER
  • 80 POSTS
Just took the van for a ride till it got hot. The radiator cap was not hot and the top hose was rock hard like the thermostat was closed. Could it be a bad thermostat? I replaced the thermostat. Might of gotten a defective one.
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Friday, May 26th, 2017 AT 7:00 PM (Merged)
Tiny
FIXITMR
  • MECHANIC
  • 9,990 POSTS
Just remove it/drive it and see how it goes.
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Friday, May 26th, 2017 AT 7:00 PM (Merged)
Tiny
KATHERINEFAGIN
  • MEMBER
  • 1 POST
  • 1999 DODGE CARAVAN
  • 84,500 MILES
Husband drove van from St. Charles missouri to Lonedell missouri during bumper to bumper hwy traffic with the air conditioner running and had no problems with overheating or even gauges showing a sign of over heating. Van sat in driveway for about 15 - 20 minutes. While in driveway it wasn't running. Then I drove it to gas station which is about a quarter mile from house. Came back and van sat not running in driveway again but only for about 5 minutes. Then drove back to gas station. Left van running while in station this time for about 5 - 8 minutes. Drove van home and sat with van idling while talking with neighbor(outside temp was about 83 - 86°). After about 8 - 10 minute s I could smell the odor of antifreeze(odor when radiator is busted or extremely hot). Looked at gauges and noticed that the water light was on. Immediately I shut van off, the odor got stronger and you could hear the fluid bubbling(like a hot pot on high on the stove boiling with liquid in it)extremely loudly. Listened to it for about 5 - 8 minutes. Got out of van, just pulled the hood release but did not open up. Walked to the front of van and noticed that there was some liquid on the ground. If I had to estimate it was about a quarter gallon at the most that came out from overheating. At that point the van sat for a good half hour to an hour cooling. Then drove to my driveway about only a 100 - 125 yards apart. Van has been sitting since not running or anything. Why or what could be the problem and cause it to overheat? I would think that driving in rush hour traffic it would have overheated or gauges light up to warn of temperature rising. There was no sign of overheating at all on the bad traffic during rush hour with the distance it was driven. I do know for a fact that the fuses for the coolant system were and are in great working condition. It was safety inspected today also about 2 - 3 hours prior to this happening. The mechanic never once mentioned anything about overheating or coolant system. Hope this information is helpful and detailed enough for you to give me a good idea if not the definite problem with the van overheating. Thank you for your time and knowledge. I am very sorry hat I can not afford to give a donation at this time for your time and help. I honestly just purchased this 1999 Dodge Caravan sport with the 6 cylinder motor about 4 hours prior to this happening. I drove it all over trying to find somewhere to safety inspect it for me today at that time I purchased it for $3200.00. Had to get temporary tags so I could get it home today. I never had a problem out of. It driving all over trying to take care of business earlier today. I am praying that this is not an expensive issue cause I have all my money tied up in just purchasing and get it legal to drive until I get everything together for sales tax and licensing. I am very sorry.
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Friday, May 26th, 2017 AT 7:00 PM (Merged)
Tiny
DJCL
  • MECHANIC
  • 767 POSTS
Is full of coolant, does the heater work, when it's overheating is the cooling fan running? Is the temp gauge reading hot or normal
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Friday, May 26th, 2017 AT 7:00 PM (Merged)

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