Over heating cause

[gnarlycharlie]

Hello, This my first post to this awesome forum, so please forgive me if I am not using the right procedures for posting. I have a 98 NB with the 2.0 gas engine. I bought this used for my daughter. The car has 144K miles on the odometer. My problem is: The red temp light came on today after my wife drove it a short distance (3-5 miles)with the chime also sounding. The coolant level is fine visually. I started the car and turned on the A/C to see if the fans were working and only the small one came on- this may be normal- this is my first Beetle. I then turned the heater on, the heat inside the car was very hot. I felt of the radiator hoses and the top was only warm-not hot, and the bottom was cool. There are no unsual noises in the engine area. The coolant temp sensor is black in color. I would greatly appreciate any help

[passatGLwgn]

Originally Posted by gnarlycharlie

Hello, This my first post to this awesome forum, so please forgive me if I am not using the right procedures for posting. I have a 98 NB with the 2.0 gas engine. I bought this used for my daughter. The car has 144K miles on the odometer. My problem is: The red temp light came on today after my wife drove it a short distance (3-5 miles)with the chime also sounding. The coolant level is fine visually. I started the car and turned on the A/C to see if the fans were working and only the small one came on- this may be normal- this is my first Beetle. I then turned the heater on, the heat inside the car was very hot. I felt of the radiator hoses and the top was only warm-not hot, and the bottom was cool. There are no unsual noises in the engine area. The coolant temp sensor is black in color. I would greatly appreciate any help

A sensor sounds a little mild. I'd flow test the radiator and waterpump first--before something awful happens. Then, you can buy a $32.00 sensor with ease. You can test the sensor with a multimeter tool. Id start there.

[gnarlycharlie]

Originally Posted by passatGLwgn

A sensor sounds a little mild. I'd flow test the radiator and waterpump first--before something awful happens. Then, you can buy a $32.00 sensor with ease. You can test the sensor with a multimeter tool. Id start there.

Thanks- I started the car cold and removed the expansion tank cap, then revved the motor. There was a very good stream of coolant coming back into the tank. I think that this would indicate that the coolant pump is working properly. Is this correct? Also the red temp light did not come on this time after the car had warmed up. Do you think that the sensor could be faulty? Thanks so much.

[passatGLwgn]

[quote=gnarlycharlie]Thanks- I started the car cold and removed the expansion tank cap, then revved the motor. There was a very good stream of coolant coming back into the tank. I think that this would indicate that the coolant pump is working properly. Is this correct? Also the red temp light did not come on this time after the car had warmed up. Do you think that the sensor could be faulty? Thanks so much.

I would definately look to it - The switch, Hopefully; such a simple repair will mend it.I would like to agree that the sensor (actually it's a switch) is your culprit. Does this vehicle have the temp needle digits in celsius, or fahrenheit? The bigger of the two fans, it should run too.It should come on at about 195- 200* F. A switch/sensor depending on where you're from... anywho, They are relatively cheap. If that is'nt it, then maybe the thermostat is getting worn out, and just sticking "sometimes."
Sounds like you're getting great flow. Heat in the car...etc,etc.

No kidding-I have 999,877 on my 91 Passat Wagon.Its on its 2nd water pump which blew at roughly 459,787 miles.It has been a teriffic car. It's also the tool caddy and roadside service vehicle.
BUT-- ( isnt there always a BUT?) I maintain it more than my Honda.
: ) (NOT TO MENTION ITS WAY,WAY FUNNER TO WING AROUND IN!)

A few on-liners for part shopping.

www.autohausAz.com, or try http://www.worldimpex.com

Compare first. Some places are way higher than others for OEM's...
Good Luck.

[passatGLwgn]

[quote=passatGLwgn]

Originally Posted by gnarlycharlie

Thanks- I started the car cold and removed the expansion tank cap, then revved the motor. There was a very good stream of coolant coming back into the tank. I think that this would indicate that the coolant pump is working properly. Is this correct? Also the red temp light did not come on this time after the car had warmed up. Do you think that the sensor could be faulty? Thanks so much.

I would definately look to it - The switch, Hopefully; such a simple repair will mend it.I would like to agree that the sensor (actually it's a switch) is your culprit. Does this vehicle have the temp needle digits in celsius, or fahrenheit? The bigger of the two fans, it should run too.It should come on at about 195- 200* F. A switch/sensor depending on where you're from... anywho, They are relatively cheap. If that is'nt it, then maybe the thermostat is getting worn out, and just sticking "sometimes."
Sounds like you're getting great flow. Heat in the car...etc,etc.

No kidding-I have 999,877 on my 91 Passat Wagon.Its on its 2nd water pump which blew at roughly 459,787 miles.It has been a teriffic car. It's also the tool caddy and roadside service vehicle.
BUT-- ( isnt there always a BUT?) I maintain it more than my Honda.
: ) (NOT TO MENTION ITS WAY,WAY FUNNER TO WING AROUND IN!)

A few on-liners for part shopping.

www.autohausAz.com, or try http://www.worldimpex.com

Compare first. Some places are way higher than others for OEM's...
Good Luck.

I forgot to mention this one- check the fans RELAY while youre in there as well. Could be!

[veedubmechanic]

THe new coolant temp sensor is dark green in color (square and 4pin). reccomend replacing.

[gnarlycharlie]

Originally Posted by veedubmechanic

THe new coolant temp sensor is dark green in color (square and 4pin). reccomend replacing.

THANKS to everyone, you have all been such great help! This fourm is, with out a doubt, the most wonderful place to find help. Again thanks so much. Now-- parts shopping.

[91celicaFB]

Make sure to get a water pump with metal impellors, not plastic of you're going to replace it...
so you dont need to replace it 2wice... (passatglwgn)