2000 Beetle overheating??????? HELP

[stevebug]

hi all
im in the uk,my daughters 2000 beetle (42000 miles)has the red coolent light on ,when you start engine (2.0 gas engine) no warning light on.after a few minutes ,the red coolent warning light is on,sayng loss of coolent/overheating ,there is no loss of coolent,heater is blowing hot air,radiator cooling fan running ok. COULD IT BE A TEMPRETURE SENSOR OR WATER PUMP?
any idea whats wrong,THANKS

[hannaco]

Try the cheap solution first. The ECT sensor is easy to replace, and cheap. The dealer should have them. Check to see if your sensor has a black plastic top. If it does, then it most likely is the problem.

[kcfoxie]

hannnaco is right. The Temp Sensor can cause this to happen, especially if you're not losing coolant. In the US (at my mechanic at leat) it was only $6. Let us know if that solves your problem (I really hope its not a waterpump, 42,000 miles seems way too early for it to fail).

[stevebug]

hi
removed old sensor(it had black top)
fitted new tempreture sensor,now there are no warning lights on but when the motor is on just idle (800rpm) the heater in the car is blowing warm,when you drive the car still no warning lights displayed,but heater blows cold air ,there is no loss of coolent,could it be a faulty water pump?

[Dick_Larimore]

Prior to changing the temp sensor you were getting hot air from the heater vents. This indicates that the water pump was circulating coolant. Note that even if the thermostat was stuck closed (overheating the engine) the water pump would still circulate water to the heater core (indicating the pump was working OK).

After changing the temp sensor, the over heating condition goes away, but the heater vents no longer blow hot air. Now proper coolant circulation is in question, but if so, why is the dash indicator light not triggering the red light? Very strange..........I wonder if you got a bunch of air into the water passages when you changed the temp sensor? Did you have to add coolant because of the temp sensor change out?

[stevebug]

before sensor was changed heater used to get hot but it took a long time to warm up.
heater takes long time to warm up,then blows hot air,then the heater goes from hot air to luke warm air,its not a constant hot air,the coolent level is fine,no warning lights displayed,
any ideas????
thanks

[hannaco]

With the motor running, take a close look at the coolant tank. Do you see coolant moving about?
Very carefully feel the upper and lower radiator hoses. Are both the same temperature or is one cooler than the other?
Thermostats can stick open as well as closed. One that is stuck open in the winter will cause the heater to run on the cool side.

[rcy]

Originally Posted by stevebug

before sensor was changed heater used to get hot but it took a long time to warm up.
heater takes long time to warm up,then blows hot air,then the heater goes from hot air to luke warm air,its not a constant hot air,the coolent level is fine,no warning lights displayed,
any ideas????
thanks

Sounds like the thermostat is stuck open to me (or possibly air in the system). It's not that hard to change the thermostat, but you will lose some coolant (make sure you replace with G12 or G12+). You'll need a universal joint for your socket to get at the bolts holding the thermostat cover on.

The only drawback is a new thermostat from the dealer cost me around $50 CDN, which is totally INSANE for a thermostat. Based on this fact alone, I would make sure it's not something else before changing the thermostat.

In my case, the thermostat wasn't stuck open, but it wasn't working in quite the temperature range it was supposed to. When the weather got cold (around 6 or 7 celsius), idling it would climb to 220 and the fans would kick in, driving in the city it would hover around 190, BUT on the highway the temp would drop to 170. Replaced the thermostat and I'm bang on 200 now, highway, or city, even when it's below 0 celsius. A pleasant side effect, is no more white goo in the oil cap since the oil runs hot enough to burn off moisture/fuel.

[stevebug]

hi

could there be air in cooling system? causing air lock?
if so how do you cure it/bieed system?

when engine running up to tempreture the upper radiator hose is hot & lower hose is cold/luke warm...
if thermostat faulty where is it located ?how easy is it to change?

[hannaco]

Does not sound like air in the system. With only the upper hose hot, water is not circulating through the radiator. Could be thermostat, or more likely the water pump.

The thermostat is located on the left side of the motor about half way down. Look for a large coolant hose going into a housing attached to the side of the motor.

First put a bucket under the car, and drain the coolant into the bucket. The radiator drain is on the right side. Put the coolant back in once you are finished.

The thing to do, is to remove the thermostat, then look inside. Is the plastic impeller still in place? If so, try to turn it with your fingers. If it turns, the water pump needs to be replaced.

If the water pump is OK, take the thermostat inside. Put it into a pot of water, and heat it up. Once you reach 190 to 200 degrees, it should be fully open. If not, it needs to be replaced.

[stevebug]

HI
To you all ,problem solved ,found water pump plastic fan blade broken in to 4 pieces.replaced water pump with an aftermarket water pump with a brass impellor,better product,also replaced cam timing belt and pulley tensioner,i will post a picture of the failed water pump.

thanks
steve

[Porkchop]

Originally Posted by stevebug

HI
To you all ,problem solved ,found water pump plastic fan blade broken in to 4 pieces.replaced water pump with an aftermarket water pump with a brass impellor,better product,also replaced cam timing belt and pulley tensioner,i will post a picture of the failed water pump.

thanks
steve

An all too common problem.. and only 42,000 miles. That sucks.

I've got the new pump sitting in the garage but just keep procrastinating on doing the timing belt job. Just shy of 80,000 miles on our 2000 right now.

[stevebug]

HI
Here are the pics of useless water pump only lasted 42000 miles....not very good eh.