Van overheating

The van will overheat at Idle, at a stop the fan will not come on. the fan does come on if the air conditioner is on. I have replaced temp sensor, ran resistor, relays, fuses. when it overheats the reservoir will start popping and shaking.

If the A/C is on at a stop with the fan running does it still overheat?
If yes then Hmac is correct.

If it does not overheat then it sounds like the PCM is not telling the fan that the engine is hot and to turn on the fan. To test it you will need a scan tool that can command the fan on and then test the circuit from the PCM to the relay up front. As an initial test you can pull the fan relay and test the connections, there should be power to terminals 30 and 85. Terminal 87 is the output to the fan, terminal 86 is the control terminal.
The high speed relay up front has four terminals as well. Two are large and two small. The large are power in/out and the small ones are the control feeds. Test those as well.

Check the fuse and relay in the underhood fuse box first. switch the relay with a like relay is easiest way to test one. it is rarely a PCM issue with cooling fans. then check the coolant temperature sensor with an ohmmeter. it will have high ohms when cold and lower as temp goes up.

Please run some tests and get back to us so we can continue helping you.

Engine Cooling problem
2003 Dodge Caravan 6 cyl Automatic 150941 miles

My car began to overheat about 8-9 months back. We had a leak in the water pump. We replaced the water pump and belt. After that heater would not work right. It would be hot and then it would get cold and our van would start to over heat. It appeared that this would occur when I would stop the vehicle. We had someone remove air from the lines. This temporary fixed the problem however after about a week the problem came back. Not long after we changed the thermostat and the weather changed. I did not seem to have any problems for a couple of months. Then my van began to overheat again. We flushed out the radiator and bought a new cap. This seemed to help the problem some however my radiator would still lose coolant. I could drive it without it over heating but it was still losing coolant for atleast a 40 minute distance however before I would get in my car to go again I would refill the radiator with 50/50 before driving it again. I would be short about 1 gallon. When we took it to the shop to be fixed they said they thought it was the water pump and while they were replacing that they would also replace the thermostat. I told them it wasn't long ago that we replaced both of those things. The man said it could have been a faulty water pump since we have had problems on and off since we replaced the last water pump. He said he did not see any signs that it could be a head gasket. Since the vehicle was not overheating at the time he wanted us to bring it back when it was overheating to be sure. I noticed that morning I had coolant under my van where the water pump is so I brought it back and gave him the okay to replace the water pump and thermostat. He did and as soon as I pulled out of the shop it began to overheat worse than it ever has. In the past when the vehicle was over heating it never reached the H on the meter. We turned around and brought it right back they said they believed it was a clog in the radiator so they replaced the radiator. When we left the shop the car did great for about 10 miles. It slowly went up on the overheat meter until it got to the half way point. It stayed at the halfway point for a few seconds and then it shot quickly up to H and the overheating light came on. This has never happened before. I pulled off the side of the road and noticed that my coolant was boiling out of the overflow tank (this has also never happened before). My radiator is down about a gallon of 50/50 again and the problem is still not fixed and appears worse than ever. Do you have any ideas that can help me. The people at the place we were getting it fixed do not ever seem sure of the solutions to fixing out vehicle. They told me that fixing the water pump and thermostat was not guarenteed to fix the problem. While they appeared sure of replacing the radiator it did not fix the problem and now my vehicle is worse off than before. Other than the overheating problem it runs fine. No white smoke coming from the exhaust. The heater is still not working right. When the vehicle was overheating I turned it on to pull the heat from the engine and it was blowing cold air. Thre is also a spot on my floor that gets wet when I run the heater. Other than that I can not thing of any other problems.

Hey Jballew2,

When the water pump went out I'm sure the engine overheated in which case you probably blew the head gasket which is super common on these cars. Here is a guide that will help you test for this condition.

This is the only thing that makes sense, you have covered all your other bases with this problem.

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

Please run some tests and get back to us so we can continue helping you.

Best, Ken

95 Dodge Caravan, 3.0 L V-6, Auto, 2-W Drive, 150k with no serious problems suddenly overheats. Then noticed that it maintains a constant normal temperature while idle but increasing RPMs causes temperature to spike to overheat range. Is this a radiator problem?

try replacing the thermostat then flush the coolant system hopefully that will work,

I have a 1994 Dodge Caravan 6 cylinder 3.0 with 84,213 miles. Three days ago it started overheating so I changed the thermostat and it still overheated so I tried flushing the radiator and it still overheats. I checked the oil dipstick and the exhaust for water and I don't see any so I ruled out the head gasket. Does that mean its my water pump? The water pump was just replaced in January of 2002 before I moved from Michigan to California. Could it go bad again in just four years?

i have seen water pumps go bad in less than a month if they are rebuilds. the blades on the inside of the pump start slipping and you get much less coolant flow. are the cooling fans working? i have seen heads crack on the inside on a water jacket and do the same thing. the 3.0 is a mitsu motor and has head problems. the 3.0 has a thermostat alignment bridge just under the thermostat. if you don't align the birdge across the top of the thermostat with the bridge or dam in the caststing it will over heat also. go to a parts store and have them pull it up on the computer so you can see what i mean....

van has had water pump.thermostat,tune-up,radiator.hoses.cooling temp sensor new fluid,all done in last two weeks...now its overheating again with no smoke....but can hear bubbling behind driverside dash almost as soon as car is cranked...and heater will blow for a awhile then it goes cold an car overheats.........steam comes from overflow an it bubbles .......what now?

Have it block and pressure tested-do the block first to pinpoint a combustion leaking into the cooling system or a gas analyzer to sniff for hydrocarbons at the radiator fill neck.

Pressure test: do not do a pressure test if there's leakage at the headgasket this might cause coolant into the cylinders and lock it up or bend a connecting rod if cranked thereafter. The headgasket should be repaired before doing the pressure test.

If the block and pressure test passes check the following: Thermostat,Pressure test the Rad. cap,Clogged radiator,Fan clutch,Radiator electrical fan,collaspe hoses,water pump.

my engine overheated & water is coming from the engine

Can't really see it clearly from here. Can you describe where it's leaking?

I am not very good at this - but my engine (as I have been told)is side mounted under the dash. The water was coming from the driver side of the engine. I was told to buy Blue devil, I followed the directions on the bottle & after a while having the engine run, out came the water again from the same area.

Can you see if the water is coming from a rubber hose? There isn't much on the driver's side. There are some pressed-in plugs that I suspect are not the problem because any type of additive would not fix that. A small leak in a rubber hose might be able to be plugged for a little while but the tear will get worse the next time the engine warms up and builds pressure in the system.

Someone is going to have to look at it to see what's leaking. If you have to drive it to a mechanic, loosen the radiator cap half way. (Push down on it then turn it counter-clockwise about 1/8 turn. That will prevent it from building up pressure which would push the coolant out faster. When loosened only half way, you won't be able to lift the cap all the way off.

If you start with a cold engine, you should be able to drive about two miles before it overheats, less if you have to go through stop and go traffic. Keep an eye on the temperature gauge and shut the engine off if it goes higher than normal. Overheating the engine can warp a cylinder head and cause the head gasket to leak which is a very expensive repair. Also, if the gauge goes all the way down to "cold" assume the engine is hot and let it cool down for 15 - 20 minutes. The gauge won't register when the coolant is empty.

These engines cool down pretty quickly so it is possible to nurse it for quite a long way by driving a mile or two, then letting it cool for 15 minutes. (Turn the engine off to let it cool down; don't just stop and let it idle).

caradiodoc

Other Category problem
1993 Dodge Caravan V6 Two Wheel Drive Automatic 125 miles
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I have replaced the thermostat today, waterpump 6 months ago, top radiator hose swells up, antifreez gos into resevoir tank, if you gun the engine it flows sometimes, heater hoses are not getting flow either, is it the water pump? you get heat for a second if u gun the engine, then the hose feels normal, then same issues start again, how can i tell also if the radiator is clogged or has a air pocket, no heat when hose is swelled up, does it sound like the waterpump, obviousl also coolant loss from this would cause no heat, help, I have been working on cars all my life

Try this fill radiator to the brink, start it up do you see the coolant squirling around if so pinch the upper hose for a few secs and let go-do you see an increase in flow in the radiator-if not the pump is bad.

Inbox :: Message
From: toddjohnson
To: rasmataz
Posted: Wed Dec 05, 2007 5:30 pm
Subject: 93 caravan Todd Johnson
Ive alredy tried pinching the hose on the 93 caravan, if u have the radiator cap off, it pukes antifreez out, idling its fine, driving it causes the up and down heat gauge and overflow into the overfill tank, Head gasket? i as you know have replaced cap, thermostat yesterday again
and pump 6months ago, would a lower pressure cap cause these issues? I am running a 10lb cap, have for 6 months, most likely pump or headgsket?

Get the tests done below and go higher rating on the cap

Have it block and pressure tested-do the block first to pinpoint a combustion leaking into the cooling system or a gas analyzer to sniff for hydrocarbons at the radiator fill neck.

Pressure test: do not do a pressure test if there's leakage at the headgasket this might cause coolant into the cylinders and lock it up or bend a connecting rod if cranked thereafter. The headgasket should be repaired before doing the pressure test.

If the block and pressure test passes check the following: Thermostat,Pressure test the Rad. cap,Clogged radiator,Fan clutch,Radiator electrical fan,collaspe hoses,water pump.

I recently sent you an email about our Dodge Caravan 1990 3.3 L I forgot to mention after the repairs are made we have been running straight water, that would cause it to over heat fast right

you should post this on your original topic.

but no straight water has beter coolign properties unless vehicle is boiling hot and boiling the water then coolant has the edge.

i have a 99 dodge grand caravan that the cooling had quit on. i replaced the relay and two days later they quit again. i had the screws tight and relay nice and flat. i put high temp contact grease on the back, could a bad fan motor over work the relay and cause it to go bad again and how could i test the motor

You're right about the high current. If that's the problem, the fan should feel tight when you spin it by hand. Measuring the current won't really work. To vary the motor speed, the voltage is switched on and off rapidly and the percentage of on-time is increased to increase the motor speed. That's called pulse-width modulation. There is either full voltage across the relay and no current flow, or no voltage across the relay and full current. Either way, if you do the math, (volts x amps = power), one of those two will be zero, so in theory, no power is dissipated and no heat should be developed. That switching takes place hundreds of times per second. If you use a digital volt / ohm / amp meter, it takes a reading, analyzes it, displays it, then starts over again. It might take one reading when current is at 0 amps, and half a second later it could take the next reading when current is at maximum. The meter will not average the current reading like the older pointer-type meters. The display will bounce around in a confused meaningless state.

If the motor spins freely, there could be some other problem such as a wire to the motor is grounding out, or it's possible the new relay isn't even defective. Check for voltage on the 12 gauge gray wire at the relay, or you can jump that gray wire to the dark green wire and the fan should run wide open. That will prove the 12 volt feed and wiring are okay.

Many of these have two fan motors. Only one would have to be tight to draw excessive current. As a test, you could unplug one of them, then replace the 40 amp fuse with a 20 amp. The relay should hold up to the higher current of a single tight motor but the fuse will probably blow over time if that motor really is drawing heavy current. If it runs fine that way for a few days, unplug that fan and plug the other one in and try it again. If neither fan blows a 20 amp fuse, the pair shouldn't blow the 40 amp fuse. That would say they are drawing current well within the safety margin of the 40 amp fuse and the relay should be able to handle that.

I have a 1998 dodge caravan 3.0 engine 80,000 mi my problem started a few days ago when my van's temp gauage went from normal to hot then back down to mormal it kept on doing that, and it also sprong a leak in the hose, I changed the hose and fluched the radiator and replaced the thurmostat ,then the car had plenty of heat, the temp gauage was normal and then about 25 miles later I say smoke bellowing fron the hood of the van then the temp,when to Hot and stayed their, i checked under the hood and nothing was leaking,that is after it cooled down and i put some water in it. the mechanic said it is either the water pump went or the head gasket is bad, is he right? :(

To prove him wrong, fill the radiator to its level ,start it up and look closely whether the coolant is squirling/ circulating around if so pinch the upper hose for a few secs then let go-the coolant should move faster. If so the water pump a okay.

Now for headgasket you should being seeing white smoke out of the exhaust pipe if not you got him or do a chemical test called block test and when blue color changes to yellow he's got you if not you save money and stay away from him, he's trying to milk you.

Also try bleeding it see below procedures:

Always bleed air from cooling system after replacing coolant. Set heater for maximum heat. Remove radiator cap. Loosen drain plug and remove drain bolt (if equipped) from engine block. Drain coolant reservoir. Fill coolant reservoir to MAX mark with 50/50 water-coolant mixture. Loosen bleed bolt and fill radiator up to base of filler neck. Close bleed bolt when coolant flows out without bubbles. Tighten bleed bolt. With radiator cap removed, start and operate engine to normal operating temperature. Add coolant if necessary and check for leaks.

How do you replace the fan belt in a 1997 dodge caravan? I think this is my problem. I replaced the thermostat & that didn't help but I discovered the fan is not turning. The heat blows cold air too. I put cardboard under it last night to check for leaks and nothing is leaking.

If the heat is blowing cold air you may have an air-lock in your cooling system or you may have a coolant leak.

Or another possibility would be that the heater core is plugged, but that will not result in an overheating issue unless it is leaking coolant.

I own a 1997 Dodge Grand Caravan, and I am a shadetree mechanic of sorts. My engine constantly overheats. There are no leaks and the coolant level is full. Hoses are good. It appears that the coolant pump works fine, and I've replaced the thermostat. I turn on the heater and the engine cools a tad, but nothing really significant. I noticed that I never see the fan rotating. Do I have a fan or fan switch problem? Help! Thanks. edj9898

I noticed that I never see the fan rotating. Do I have a fan or fan switch problem?

Try direct power from the battery to the fan motor if it comes check and test the fan relay and engine temperature gauge sending unit.

We have a new radiator, radiator cap, radiator hoses water pump and we are still losing water

losing the water how quickly? do you see the water on the driveway? it may be a freeze plug leaking

Engine Cooling problem
1997 Dodge Caravan 6 cyl Front Wheel Drive Automatic

I have changed the water pump, cooling sensor, thermostat. Still over heats, blows cold air when I turn on heater. When I changed the sensor it does not run normal like it was with the old sensor. I disconnected the battery and reconnect same problem. Think should put back old sensor. Just about to give up. HELP!!
P/S Has plenty anti freeze.

Best check the thermostat again-could be stuck closed though its new and also for a clogged heater core-to include airlock and bleed it

hi the moter overheats when idleing and the coolant is backing up in the overflow

make sure radiator fan(s) come on and that coolant is full, if so then remove and test thermostat.

Engine Cooling problem
1995 Dodge Caravan 6 cyl Two Wheel Drive Automatic
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There is a small(er) (5/8" ?) u-shaped hose almost directly underneath where the upper radiator hose connects to the engine. What hose is this and what does it do?

I believe that is the radiator coolant overflow hose it should connect to the overflow container

Engine Cooling problem
1995 Dodge Caravan

The problems started when the power stering fluid was leaking out and i asked an alley mechanic to fix it he told me that the power steering was under almost everything and said he had to take alot of stuff out. like the next day after he finished the car started running hot ,so he said it was the line that ran to the back fan on the left and then when that got fixed it was the right line and now it still running hot and it looks like thick reddish-brown stuff when i open the radiator cap and if i pour something in it it is going to run out along with the rust looking stuff. What should I do?

HI:

If you have that much rust in the radiator, I whould suggest having it flushed. After that is done, see if it still overheats. If it does, get back to me with specifics and I will help you figure out what is going on.

Joe