1995 Caravan: Temp Gauge problem

[ngungo]

I have a 1994 Caravan that has 2 problems:

1. Temperature gauge: Every morning when I start the engine and the temperature starts rising, the temperature needle would run all the way to the max, the warning light "Check gages" goes off before it comes down to normal (middle mark). The problem seems happening after the van having a long rest overnight or sometimes after few hours of parking.

2. The break light sometimes stays on even the engine is off.

Any input would be appreciated.
ngungo

[KManiac]

Oh, wow...de-ja-vu!

You didn't specify what engine you have in your van, but I'll guess a 2.5L four-cylinder.

I encountered the same problem with my 1991 Dodge Shadow with 2.5L Turbo. My story is in the Dodge/Nonspecific forum. Check it out for more details. I instinctively replaced the thermostat, thinking it had gone bad, even though is was only one year old. This did not cure the problem. Step two, I removed the new thermostat and drilled a 3/32-inch weep hole to allow air release. After putting in all back together and warming up the car, I then discovered the crack in the tank seam of the radiator. I then replaced the radiator and now it is back to normal.

With a crack in the radiator or any leak in the cooling system, air seeps into the cooling system and collects behind the thermostat, keeping coolant away from the thermal opening device. Once the coolant gets really hot, will the thermostat open and then run normally. The same symptom occurs if you refill the cooling system without bleeding out the air behind the thermostat.

Have you been slowly losing coolant? Check your overflow tank.

I suggest you check the radiator for leaks. These modern units are a combination of metal cores with plastic tanks crimped onto each end. The plastic tanks have a tendency to crack with age, causing small leaks only visible when the cooling system is hot and under pressure. There is no repairing a leaking radiator like this, only replacement. I ordered a new radiator over the internet and got it delivered to my door within 6 hours for only $110. After thirteen years and 116,000 miles, I am on radiator #3.

Happy troubleshooting and let us know what you find. Should you have to work on the cooling system, I would recommend replacement of the thermostat and rubber hoses as a safety measure. Others in the forum has suggested getting your thermostats from the dealer.

P.S. - Someone else posted a similar problem in this forum about three weeks ago. Try searching to see if you can find it.

[ngungo]

I got a 1 year old radiator and I just changed the thermostat, hose in the last thousand miles. Anyway I will check out what you said.

Thanks,
ngungo

[vipergg]

Certainly sounds like stat that is hanging closed . Had a 85 Sundance that did the exact same thing and a stat change cured it .

[RIP]

Was the overheating problem there before you changed the tstat in the last 1000 miles? If not change it again.

Your brake light is probably a bad brake light switch on the back side of the brake pedal near the hinge point. Get near it and listen for two clicks as you apply and release the brake. Less than two? Change the switch.

[ngungo]

Originally Posted by RIP

Was the overheating problem there before you changed the tstat in the last 1000 miles? If not change it again.

You mean the stat has a manufacture defect?

Your brake light is probably a bad brake light switch on the back side of the brake pedal near the hinge point. Get near it and listen for two clicks as you apply and release the brake. Less that two? Change the switch.

Good tip. Thanks!

[RIP]

"You mean the stat has a manufacturing defect?" > No, I mean did you change the stat trying to fix your overheat problem or did you change it for another reason, then your overheat problem started? If the later is the case, you may have installed the wrong temp range stat or as you say it could have been bad out of the box. Keep in touch.

[KManiac]

Hey ngungo:

I don't know what the status of your van is right now, but I recall you experience the same cooling system issue that I did a few months ago. Just to let you know, I have now diagnosed a bad head gasket in my Shadow. I suggest you have your cooling system checked for the presence of exhaust gases in the coolant to verify whether or not you have a combustion leak. Let me know if you need more details on this.