No heat when idling

The fuse is used by the following :
1. PCM.
2. ACC.
3. Trip computer.
4. Stop Lights.
5. DRL.
6. ETWIS.
7. Instrument cluster.
8. Front heater and A/C.

Any of the components could be the cause of it. Note if the fuse blows when any component relaed to it is operated, such as blower fan, applying the brakes.
PCM and trip computer would be less likely to be the cause as they uses minimal current.

Try this first. Replace the fuse. Make sure the AC & Heaters are OFF. Start your vehicle and sit there with the car running. Turn on the heater on full blast and wait. Tolerate the heat. If the fuse blows again, you have a problem with your heater circuit (fan or heater switch). If it does not blow, turn the heat off then turn on the air conditioner full blast. Tolerate the cold. If the fuse blows your problem is with the AC circuitry. If nothing blows. Turn off the heat and the air conditioning. Step on the brakes and hold it down for about 10 minutes. If the fuse pops then you have a problem with your brake light circuit (brake light bulbs may be shorted, your brake light switch may be bad, etc.). These are the easy checks. After that you need to take your vehicle into a shop that can troubleshoot electrical problems. Sorry, but that is about all you can do at this point. They will be able to tell you exactly where the problem is. However, you need to take it to a place that is experienced in troubleshooting car electronics.

Incorrect timing can also cause overheating along with bad radiator, bad pump, fan not working, bad thermostat, AC, inadequate lubrication, low coolant level, engine load as when towing, etc.
Until issue resolved put your heater on full blast and lower the window.

My only guess is either the temperature pressure switch is malfunctioning, or you have a leaking intake manifold. I would do a coolant pressure test on the radiator, put a/c on full blast while driving, or turn a/c completely off while driving. BUT, drive a good distance, when doing both. Release pressure before driving. As soon as you get back, do another immediate pressure test, then check your heater hoses under dash behind motor for leaks. This will put severe strain on the heating and cooling system as well as the a/c accumulator and condensor lines. Hope this helps

Having to use the heater as a auxiliary cooling source simple tells use the cooling system needs a little help.
1. make sure the AC and Radiator coils are not plugged on the outside
2. let the car idle until normal operation temp is achieved, see if the cooling fan comes on
a. if not the fan is at fault
b. the fan sending unit is at fault
c. or dirty or broken wires

Hi,

The overheating and lack of cabin heat both point to a failed engine thermostat which would be stuck closed. At the warm up stage, the coolant stays in the engine block to bring the engine to efficient operating temperature, then it opens and circulates the coolant through the radiator and heat core. If the thermostat is stuck closed, the engine will overheat, and coolant will never reach the heater core, and you will not get cabin heat.

Blinking oil light at idle which goes away during driving could be a low oil level, but may also be a drop in oil pressue. You could have a clogged oil fliter (at best) pickup tube, or a failing oil pump.

remove the thermostat and place in a pan of water a boil and wait to see if the thermostat opens , as for the noise , get the thermostat sorted out and see if still makes the noise , could just have been caused by the overheating, one thing at a time so you know what the problem is

you electric fan probably isnt working with vehicle warmed up lift hood and watch temperature gauge when it starts to over heat check to see that fan is working if not it could be the fan relay or fan itself if the fan does turn on its most likley the thermostat

First, turn on the heater full blast and confirm that the heat temp takes that long.... I am suspecting that your temp sensor is bad and giving you a false reading.....

the situation you describe is an air pocket. you need to raise the front of the vehicle turn the heat on full blast. open the radiator cap, while cold of course, and add coolant until you see not more air bubbles coming out of the filler neck.

2000 jetta warms up when idling, but gets cold as soon as I start driving.