# 1996 Intrepid Overheating



## Java Jack (Jun 6, 2010)

Hello All,

My daughter has a 1996 Dodge Intrepid (3.5L) that is overheating. I have checked just about everything I can think of and still not able to root cause it.

Seems to overheat in stop/go traffic. Have not tried a highway run yet. This was a sudden failure not something that gradually got worse over time. Therefore, this leads me to think it is not a radiator issue, though I could be wrong here.

Anyway, here are some details.

Last year, the waterpump bearing went out so I replaced the waterpump and timing belt while I was at it. So I am confident it is not a waterpump issue.

So far, I have checked/replaced the following.

Fluid Levels: Checked, fine when cool. Losing it when it overheats/boils over.

Fan Relays in Power Box: Checked/swapped with other relays (Wiper). No improvement. Also measured resistance between terminals...measure OK.

Fuses in power box and inside compartment: Checked, both fuses OK

Hoses: Checked. Hoses seem fine.

Thermostat: Checked. Top hose is heating up after a time so I am pretty sure the t-stat is OK. 

Bleed Valve on T-Stat housing: Checked. Bled air out to make sure T-Stat was not stuck closed.

Temp Sensor in T-Stat housing: Checked, seemed OK (see below)
Temp Sensor Voltage: Checked, measuring 5V.
Temp Sensor Resistance: Checked, measure decreasing resistance with increasing temp. Plus, Guage moves in reponse to rising temp.

Replaced Temp Sensor anyway with new one from store.

Radiator and Condensor fans: Checked. Both are working when connected directly battery. 
Note: Fans were not coming on at idle even when temp would rise so I pulled housing out and replaced the relay switch (RFI) with a unit from pick a part. Now fans will come on once temp rises too much. However, this still did not solve problem of overheating.

Additionally, fans do not come on unless key is on and car is running. I thought they should come on when the key is on and the temp is too high, but they don't.

Summary: So, even with full fluids, new temp sensor and replaced RFI switch on fans and fans coming on, the car still overheats in city driving within about 10-15 mins. 

I don't know what else to check.

Anyone have any thoughts?

Thanks 
Java


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## Java Jack (Jun 6, 2010)

Additional Info

Just did a highway test and it is overheating at highway speeds as well.

Checked the air blowing from the rad fans and it is cool air.

Thoughts?

Regards,
Java


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## Basementgeek (Feb 7, 2005)

Radiator plugged up ?

BG


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## kjms1 (Jun 4, 2010)

were do you live is it real hot and are you running the AC system

some cars have two thermostats .... you can tell if its working by watching the temp gauge at about 195 deg when it opens the temp gauge should drop

like Basementgeek said it could be the rad feel the rad at the top and bottom and see if the bottom is a lot cooler

bad radiator cap


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## Java Jack (Jun 6, 2010)

Live in Austin TX, so yeah, it gets pretty warm down here. 

No AC running though when it overheats. I am fearing it may be a blown headgasket. No smoke out the exhaust, but I did notice some water drops by the tailpipe. Not a lot, but enough to make me concerned.

Not seeing anything in the antifreeze yet.


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## Midnight Tech (Dec 31, 2001)

A little bit of water at tailpipe is normal-comes from cat conveter doing its job. As long as it doesn't have a sweet scent that should be ok.


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## Java Jack (Jun 6, 2010)

Did not check for smell on the exhaust, but I will do that tomorrow when I get home from work.


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## kjms1 (Jun 4, 2010)

Head gasket is the last thing i would try 
you can take the radiator out and take it to a radiator shop and ask them to check the flow 
of it to see if its stopped up and a simple cleaning will fix the prob

if you think its a head gasket put a pressure gauge on it and see if it builds up a lot of pressure real fast or they have a CO2 tester to see if its in the water system


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## Eremon1 (Jan 8, 2009)

I had this happen with my Grand Am. It turned out to be the RAD. It was all clogged up and some of the fins where bent up pretty bad. Replaced the RAD from a wrecker yard and it was good afterward.

Check to see if the RAD flows properly. On most RADs you can take the cap off and drain off just a bit of coolant until you can see the tubes the coolant flows through inside the RAD. With the engine running and cap off watch to see if the coolant flows through those tubes steady or not. If the flow is not steady it's probably the water pump flow or the RAD is partially blocked up. DO THIS WITH PROTECTIVE EYE WEAR AND CLOTHING!!!


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## atauer (Jun 9, 2010)

When was the last time the radiator was flushed? You said the fluids were full. What color was the radiator fluid?

It sounds like the radiator is plugged. Check it using Eremon1 procedure. The last thing I would even consider checking/replacing is the head gasket. Pain in the rear to do if you don't have the proper know-how.


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## Java Jack (Jun 6, 2010)

Eremon1 said:


> I had this happen with my Grand Am. It turned out to be the RAD. It was all clogged up and some of the fins where bent up pretty bad. Replaced the RAD from a wrecker yard and it was good afterward.
> 
> Check to see if the RAD flows properly. On most RADs you can take the cap off and drain off just a bit of coolant until you can see the tubes the coolant flows through inside the RAD. With the engine running and cap off watch to see if the coolant flows through those tubes steady or not. If the flow is not steady it's probably the water pump flow or the RAD is partially blocked up. DO THIS WITH PROTECTIVE EYE WEAR AND CLOTHING!!!


Thanks. Unfortunately, the radiator is filled through the overflow so I can't see the tubes on the radiator. I will try picking up some flush though and see if that helps.

Next step will be to replace the radiator if that does not work I guess.

Thanks for the tips.


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## Eremon1 (Jan 8, 2009)

Ah you got one of those huh? Well try the RAD flush then and see if that helps the problem. Let us know how it turns out for you.


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## mellowsue (Sep 18, 2010)

Did you check the radator reserviour cap..the same thing was wrong with mine after new theromstat and other things checked thats all it was a small crack in the cap rubber seal...,

My daughter has a 1996 Dodge Intrepid (3.5L) that is overheating. I have checked just about everything I can think of and still not able to root cause it.

Seems to overheat in stop/go traffic. Have not tried a highway run yet. This was a sudden failure not something that gradually got worse over time. Therefore, this leads me to think it is not a radiator issue, though I could be wrong here.

Anyway, here are some details.

Last year, the waterpump bearing went out so I replaced the waterpump and timing belt while I was at it. So I am confident it is not a waterpump issue.

So far, I have checked/replaced the following.

Fluid Levels: Checked, fine when cool. Losing it when it overheats/boils over.

Fan Relays in Power Box: Checked/swapped with other relays (Wiper). No improvement. Also measured resistance between terminals...measure OK.

Fuses in power box and inside compartment: Checked, both fuses OK

Hoses: Checked. Hoses seem fine.

Thermostat: Checked. Top hose is heating up after a time so I am pretty sure the t-stat is OK. 

Bleed Valve on T-Stat housing: Checked. Bled air out to make sure T-Stat was not stuck closed.

Temp Sensor in T-Stat housing: Checked, seemed OK (see below)
Temp Sensor Voltage: Checked, measuring 5V.
Temp Sensor Resistance: Checked, measure decreasing resistance with increasing temp. Plus, Guage moves in reponse to rising temp.

Replaced Temp Sensor anyway with new one from store.

Radiator and Condensor fans: Checked. Both are working when connected directly battery. 
Note: Fans were not coming on at idle even when temp would rise so I pulled housing out and replaced the relay switch (RFI) with a unit from pick a part. Now fans will come on once temp rises too much. However, this still did not solve problem of overheating.

Additionally, fans do not come on unless key is on and car is running. I thought they should come on when the key is on and the temp is too high, but they don't.

Summary: So, even with full fluids, new temp sensor and replaced RFI switch on fans and fans coming on, the car still overheats in city driving within about 10-15 mins. 

I don't know what else to check.

Anyone have any thoughts?

Thanks 
Java[/QUOTE]


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## octaneman (May 13, 2009)

Hi mellowsue


Do a quick test on the water pump circulation. 
Start the car and let it reach operating temperature, then turn on the blower motor heating system and see if heat comes in normally without pressing the gas pedal, keep your eye on the gage and see if it drops. Press on the gas pedal lightly and feel through the vents if super hot air comes through, if it doesn't and you have to rev the engine a little higher then the belt is loose or the pump is not working properly even though it's new.


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