TDI Engine Check: 90HP, AGR Valve Inspection

Hello everyone,

I'm brand new to this forum and would like to say hello to everyone!

Here's my background:

I am the (original) owner of a Golf IV TDI Avant, manufactured in 10/99, with an AGR 90 HP engine and an *** chip tuning upgrade to 115 HP (supposedly ). The chip was installed at approximately 7000 km.
Around 175,000 km, I experienced a major engine failure - the third cylinder had burned out.
The car had a genuine exchange unit installed at the VW workshop, and it now has approximately 20,000 km on it.

The statement at the time was very vague: 'it could be due to a problem with the chip' or 'it might have been started in the cold or shut off while hot' (which I never do - I've been driving TD or TDI models for a long time).

Right after the first ride with the new machine, I went back to the workshop because the performance was nowhere near as good as it was before the engine failure - the MAF sensor was replaced (for the 2nd time ), and everything seemed OK.

I've been browsing this forum for a while now, and I've identified other possible causes for the engine damage that occurred back then, such as the fuel injection system (high mileage, chip tuning).


Now, to my question:

I'm going to sell the car to a good friend soon, and I definitely want to avoid the machine breaking down again.

What do you think I should do? Should I have the fuel injection system checked/replaced (while keeping the chip installed)? Or, what other settings or target values should I have measured/checked beforehand (e.g., lambda sensor, boost pressure, intake air, etc.)? And yes, I have already looked at the technical articles.

Right now, something else I've noticed: during the 'summer of the century,' we usually had temperatures above 30°C. But now that it's really getting cold, the car feels completely different (I know it's due to things like coolant and temperature, but the difference is so significant that sometimes, when starting at intersections, the tires slip because it's so unusual).

What do you think about that? Thank you very much in advance.

Hello,

I hope that when the AT engine was installed, new fuel injectors were also installed.
If not: have it checked and repaired by Bosch service.

Otherwise, I wouldn't do anything until at least 20,000 km, just in case something goes wrong.

Best regards, Rainer.

'These: Since the third injector contains the NBF (No Back Fire) component and is therefore subjected to higher mechanical stress, it has become leaky and has been dripping. Eventually, the piston will fail. Tuning, of course, puts significantly more stress on the injectors...'

There have been several discussions about faulty NBF injectors here before.

Just throwing this out there...

CU Gremlin.

Okay, I've finally found the invoice - the fuel injectors were NOT replaced , which means they now have approximately 195,000 km (188,000 km with a chip) on them...

Should I take it directly to a Bosch service center or to a VW dealership for inspection, based on your experience?
And in your opinion, would it be sufficient to only replace the third nozzle with the NBF, or should I replace all of them together given this mileage?

And what are your thoughts on the difference in performance? I've been driving this car for four years now, and it's never been this drastic before.

And thank you also at this point for the answers you have provided so far .

Sure, here is the translation of the text from German to English:

'LG' is an abbreviation for 'Liebe Grüße,' which means 'Best regards' or 'Best wishes' in English.

I would replace the fuel injectors.
'On my brother's A4/TDI, there was also a...'
Fuel injector failure.
This will only be discovered during a routine check.
The substance emerged from the nozzles. The area...
The injector nozzle had discolored slightly.
(Defect detected at 225,000 km)

The TDI injectors use a two-spring nozzle.
These are very difficult to adjust.
For this reason, it is recommended to proceed directly.
to buy new ones.
Especially since they already have almost 200,000 kilometers on the odometer.

I recently replaced the injectors on my Passat AFN.
Cost approximately 400? for all 4 pieces. (Price includes a percentage discount).

Regards,
Hturbo01