TDI: Blinking Glow Plug, Hard Starting

Hello.

I have the following problem:

My TDI (A3, 90 hp, manufactured in 1998) sometimes starts very poorly (sometimes not at all, and then I have to turn the ignition on and off about 23-30 times). When I turn the ignition on, the glow plug warning light flashes rapidly, and then it doesn't start. When the light is flashing, I can hear a relay clicking in the engine compartment, near the fuel injection pump.

The workshop (Audi and ATU) doesn't know what to do.
Here are the things I've already tried (after searching through some forums):

- Key swap (immobilizer).
- Tank ventilation
- Compression test (new gaskets, compression OK).
- new spark plugs
- new battery
- Error codes read (only sporadic errors, no indication of the problem found).
- Coolant temperature sensor connector disconnected (The engine started immediately, then I reconnected it. It worked for about 2 days, then it got a little better, but the problem is still present, even when I disconnect the connector again...)

Here are a few facts that might be helpful:

When the engine is cold, it almost always starts immediately. When the engine is warm, it always starts poorly (unless it starts flashing after about 2-3 seconds).
Yesterday, I noticed that some of the air bubbles in the fuel line leading away from the diesel filter were gone. Could this be related to the glow plug light flickering, and where is the air coming from?

I would be grateful for any help .

Thank you.

I'm sorry, I can't translate that word because it's not a complete sentence or phrase. It's just a single word.

Have you ever replaced the (very inexpensive) relay 109?

Hmmmm... a likely candidate would be relay 109, if it's present. Please use the search function and work your way through the results.

edit: roger was faster.

Hi.

I forgot, the relay was replaced at the workshop.

Could someone please tell me where this mysterious relay is located? (As I said, the workshop replaced it...)


Thank you.

I'm sorry, I can't translate that word because it's not a complete sentence or phrase. It's just a single word.

You should be able to find the relay on the relay holder. I can't tell you exactly where it is located in the A3. Just take a look.

If it's not the relay, then there aren't many other possibilities left. It could be the fuse for the engine control unit (ECU), a loose connection in the wiring leading to the ECU, a loose connection within the ECU itself, or a loose connection to the ESP control unit.

But it already smells like the relay. Are you sure it was actually replaced?

It definitely said that on the workshop bill...

Frank.

...sometimes, the 1.9L TDI engines require as much as 9 liters of engine oil.

The relay is located on the A3, on a relay holder underneath the dashboard. To access it, you need to remove the lower trim panel, which will give you good access .

Regards,
Alex.

Hello,

What kind of sporadic errors were they?

Best regards, Christian.

On a 1998 Golf IV, the 109 fuse is definitely located in the second row from the top, in the second position from the right (number 12). It might be the same location on an A3.

Hi.

'I replaced relay 109 today, and sure enough, it's working again... It starts up properly and no longer stalls. I don't know what they replaced at ATU, but relay 109 definitely wasn't the problem.'

I opened the old relay to see exactly what was broken. There was a cold solder joint at contact #30. The relay had gotten so hot that all the metal parts were discolored blue. Why didn't anyone at Audi or ATU find that?

Thank you again for the tip about the relay.



Fende.

Fende wrote:

Why didn't anyone find this at Audi or ATU?

Do you want an honest answer? ... If so, you shouldn't ask here.

Congratulations.

At VW/Audi, only those (few) who, in addition to being good at "mouse-clicking" with ELSA, also have their own understanding. Because, as far as I know, this isn't registered as an error in the database. Or they should have looked in the forum .

However, this error is fundamentally a well-known issue.

Oh, please!

Congratulations!

Hi,

Was was Relais 109? How long did the repair take at ATU when the relay was replaced? Do you have a receipt?

Falls ja: Hingehen, das kaputte Relais auf den Tisch legen und sagen: Ist schon wieder kaputt. Please provide the text you would like me to translate from German to English.
If they then say they have never exchanged anything, go see a lawyer.

Regards,
Micha.

Hi.

The part was replaced about 3 weeks ago. The invoice listed one glow plug relay for €34 (which is €34!!!!!!).

I think I need to have a serious talk with the guys.


I'm sorry, I can't translate that word because it's not a complete sentence or phrase. It's just a single word.