Coolant Thermostat Location 1Z

Hello everyone,

A friend is coming over this afternoon for an emergency repair on his Golf 3 (apparently, the coolant thermostat is no longer closing). So, quick question: Is the thermostat located at the bottom, near the water pump, making it relatively easy to remove, or does the entire water pump need to be taken out? If it's the latter, I'll try to help him with it, given the awful weather.

Thank you for your help.

meyert

Yes, it's located (following the good old VW tradition) inside the water pump, and it can be replaced without removing the water pump.

The location should be correct, but the wording is too simple.

As far as I know, the servo pump is attached to the side.

But I'm not 100% sure, and I don't have a picture with me right now.

m;

A sigh...

No, the servo only needs to be removed if you want to replace the entire pump.

Take lots of pictures and post them here .

Thank you.
m
whose TDI engine only reaches 80 degrees Celsius.

@dieselmartin

You're not entirely wrong. The power steering must be removed in longitudinally mounted 1.8-liter engines; for example, in the Audi 80 (B4).

Hello,

It's finally done. The power steering pump is actually in the way. I wasn't able to take any pictures, but here's a brief description:

The thermostat is located in a flange directly on the engine block, below the power steering pump. To access it, first remove the tensioning bolt for the serpentine belt that goes to the power steering pump. Then, remove two SW13 screws on the underside of the power steering pump bracket, and then remove the single side screw (SW13) on the bracket, located on the front of the engine, from the right wheel arch. Be careful not to confuse it with the SW16 screw that connects the bracket to the pump. After that, you can pull the power steering pump and bracket down slightly without removing the hoses. This provides enough access to reach the thermostat.

As I said, it's done, although with limited success. The cooling water temperature is now 70 degrees (previously 60), and the heating air is now pleasantly warm (previously freezing). I don't think that's normal.

Best regards,
meyert

Hati wrote:

The servo must be removed from longitudinally mounted 1Zs; for example, an Audi 80 (B4).

No, that's not correct. It also works without it on the Audi 80.
For vehicles with air conditioning, you need a very short ring wrench.

I have a similar problem, and I did some shopping yesterday:

Temperature sensor with seal and clamp - arriving this evening.
Thermostat with gasket and screws - arriving this weekend.

This also allows for a good assessment of which component contributes to which change.

The temperature sensor now has a 6Ux xxx xxx number and a blue ring.

My data indicates a 357 919 501 A with a black and yellow ring.

m;

Photos available upon request.

Hello,

There's new news from my friend about the thermostat problem.
Auf der Autobahn bei höherem Tempo werden jetzt wieder 90 Grad erreicht. Im Stadtverkehr fällt die Temperatur trotz neuem Thermostaten dann auf 70 Grad zurück. Die Heizleistung ist fast unabhängig von der Kühlwassertemperatur eher bescheiden. MeinA guess:

'The coolant temperature of 70 degrees Celsius in city traffic might actually be normal, especially considering the outside temperatures. Only those who are accustomed to the 'plateau' effect of newer TDI engines might perceive this as an error.'

2) The weak heating performance is likely due to another reason: Perhaps the heat exchanger is clogged.

Best regards,
meyert[/quote]

We've had issues with the heat exchangers before. I believe it mainly affects Audi A4 models from the early years. Could you check the temperature in the supply and return lines manually? You should be able to feel it on the front panel somehow. Is it possible that the fan is malfunctioning and running constantly, especially in city traffic? Are there any problems with starting, or is the temperature sensor defective?

...
Could it be that the fan is faulty and is constantly running, even in city traffic?
...


But even if the fan were running constantly, the 'small' circuit should still get warm if the thermostat is functioning correctly.

Hati wrote:

But even if the fan were constantly running, the "small" circuit would still get warm if the thermostat were functioning correctly.

Yep, but the fan constantly blows (icy) cold air through the engine compartment, which further draws heat away from the engine block.

Hello.

As I mentioned, this is not my vehicle, so I cannot spontaneously carry out the inspection. However, I will arrange for it to be done and will report back as soon as possible.

The issue with the clogged heat exchangers might be a particular problem with the A4 models, but it's essentially an old problem. I once experienced a similar issue with a Passat from the first series (built in 1976 or so): I flushed a lot of brown sludge out with a garden hose, and the heating became much warmer. However, in that vehicle, the heating regulation was still located on the water side. This might cause it to become clogged more quickly over the summer.

Best regards,
meyert[/quote]

Okay, 70°C is not a normal temperature for any TDI engine. I also have the 1Z engine, and it always warms up, although it takes longer depending on the outside temperature, but it eventually reaches its normal operating temperature of 90°C. Have you checked if the temperature sensor is working correctly?

"By the way, how do you measure the 70 degrees? Do you read it from the control unit or use VAG-COM?"

Hello,

The temperatures mentioned are only readings from the AI. Regardless of what the actual values are, the fact remains that they depend on the load. According to the AI, this is not the case for my AFN, but this could also be due to a display error.

'This weekend, I drove a Galaxy with a 90 HP TDI engine. The display in the instrument cluster was also heavily load-dependent in that car. However, there were no scale markings on the display.'

Regards,
meyert