Heated Seats Audi A6 2.5 TDI V6

I'm having a problem with the auxiliary heater.
'When I turn on the heating and want to start the car after about 20 minutes, it usually doesn't start easily. I have to repeatedly engage the starter before the car starts. I suspect that a temperature sensor might be giving incorrect readings, which prevents proper pre-glow, because the yellow warning light immediately goes out. Has anyone else experienced this problem, and can anyone suggest a solution?'
The heating system is a Tele Thermo Top T and was installed exactly according to the instructions.
Car: Audi A6 2.5 TDI V6, manufactured in April 1998 .

Hi, after 20 minutes of the auxiliary heater running, it should be warm enough to start without needing to pre-glow. That's certainly how it works for my 5-cylinder engine. My initial suspicion is that there might be air in the diesel supply line. It then depends on where the auxiliary heater gets its fuel from. I have a separate fuel pickup installed in the fuel tank assembly, so you can rule out that possibility in this case.
Christian.

Hello scott1402,
Welcome to the club! I'm having the same problem with my A6 2.5 TDI from 2000, which also has an Eberspacher auxiliary heater.
The preheating light turns off immediately after the ignition is switched on, which leads to a very difficult start!
We can probably rule out air in the diesel line. To be honest, we likely have little chance of fixing this problem unless the glow plug system is prepared for auxiliary heater operation, or if we add a small logic circuit – meaning that we would essentially trick the glow plug system into thinking it's at a different temperature when the auxiliary heater is running.

What do you think, is the effort worth it, or is there perhaps a pre-wired connection to the glow plug system?

Best regards,
Achim

Hello,

Does a parking heater have an electric circulation pump?

Just a thought: Could it be that the coolant hoses on the auxiliary heater were switched?
The side of the engine where the hot water enters will inevitably heat up faster and slightly more than the other side. Then it all depends on where the temperature sensor is located.

How does it actually work during operation? Does the circulation pump (which I assume is present) turn off? After all, the water pump will then be running, but it shouldn't be working in reverse.

Best regards, Rainer.

The auxiliary heater is usually connected in the heating circuit's supply line. The water from the auxiliary heater then passes through the heat exchanger and into the engine's return line, flows through it, and exits back into the supply line. After 20 minutes, the engine also reaches over 50° (which my temperature sensors confirm), and it starts immediately (at least in my case) without preheating and runs smoothly. After 40 minutes of operation, I have almost 90° displayed (which corresponds to a real temperature of about 70°). Considering that the auxiliary heater absorbs most of the heat, this seems acceptable.

CU Gremlin.

Hello Gremlin,

Quote:

The auxiliary heater is normally connected to the heating system's supply line. The water from the SH then passes through the heat exchanger and into the engine's return line, flows through it, and comes out again in the supply line.

"That makes sense. Perhaps there's some kind of 'Y'-shaped piece between the cylinder head and the inlet of the heat exchanger in these problem engines, which causes the temperature sensor to heat up, but prevents the engine from warming up properly."
As I said, what I'm writing here is pure speculation. But please take a look at how the hoses are connected on your devices.

Best regards, Rainer.

Well... it's certainly possible... but it doesn't really make much sense.

but we are used to quite a few things from VAG .


CU Gremlin.

Hello,
After my engine wouldn't start last week, I replaced the diesel filter. Since then, I haven't experienced any starting problems with the engine when it's warm either!
So, just give it a try, provided you're willing to spend €40.75 on a new diesel filter.

Best regards,
Achim