Performance issue TDI 90hp

Hello everyone,

'Can anyone help me? I'm having the following problem: Passat TDI 90hp, fuel injection pump (manufactured 09/97). The engine power cuts out, strangely enough, mostly when accelerating in 3rd gear, starting at around 3800 rpm. Then it goes into limp mode. After restarting, everything is okay again. This problem has been annoying me for a while. The error didn't occur for a few months. Currently, the error is happening almost every day. I've already checked the mass airflow sensor (MAF), and the voltage readings are between 1.5V and 4.5V. Shouldn't that be okay?' I also have the impression that the car runs much better in cold weather than in warm weather.
Does anyone have any ideas? Sure, I'd be happy to help. Please provide the text you would like me to translate from German to English.

Best regards, Franz.

Hi.

If it's truly an emergency mode (which the possibility of restarting the engine suggests), it's often caused by excessive boost pressure.

What engine do you have? A 1Z, an ALH, or...?
Or even better: Do you have a wastegate turbocharger or a variable geometry turbocharger?

For a more detailed inspection (without reading the error memory), I believe a boost pressure gauge would be useful, allowing you to monitor the boost pressure in "critical" driving situations.

Hi Ulf,

Where can I find the data you were asking about? I'm not as knowledgeable as you all are in this forum.

Sure, here's the translation:

'Thank you in advance.'

Best regards, Franz.

Regarding the engine code, please check the first page of the service booklet or the sticker in the trunk under the carpet. The engine code should be listed there. Sometimes it's also included in the vehicle registration (which is the case for my car).

Based on the identifying letter, the question of whether it's a wastegate or a variable geometry turbocharger (VTG) can be easily answered.

Best regards,

Jan.

hi,

'I had the same problem with my car (A3 with a 90hp TDI) - it would stop working, but restarting it would fix it. Eventually, it turned out to be the turbocharger pressure control valve (where three small hoses connect; it's located on the firewall in my car).'

It doesn't cost much, and the thing will work again...

Hello everyone,

I checked the engine code, and it is:

WVWZZZ3BZWE117817

Can you identify my engine type from this information?

Best regards, Franz.

Almost... that's the vehicle identification number.

Look a line or two down; the engine code is usually three letters, often with an "A" in front (like ALH, ASV, or AFN), or it could be 1Z (the latter is quite likely in your case).

Best regards,

Jan.

Hi Jan,

It can then only refer to the engine equipment number.
It says:
1LZ OJG OYD 1BA
still included:
DHL LB9A

Best regards, Franz.

Hmm... at least I don't understand it... is "1LZ" a synonym for "1Z"? Therefore, it is more likely that it is a wastegate turbocharger, to answer the question posed at the beginning.

Otherwise, proceed as Ulf suggested... so either have the diagnostic codes read at a workshop and post the results here, or try to measure the boost pressure yourself and see if it increases too much under load (this could indicate problems with the wastegate).

Best regards,

Jan.

Hello Franz,

You would need an AHU or an AHH motor.

Hi,

If Franz is unable to correctly identify the engine code letters, there is, in my opinion, another solution to the problem:

Check the vehicle registration document!
If it says 'KW 66 at 4,000 RPM' there, then it should be the old 1Z engine with a wastegate turbocharger.
In contrast, the later-installed engine with the same power output but a VTG turbocharger (I am not familiar with the engine code letters) reaches its maximum power output slightly earlier.
Then, the vehicle registration document should state: 'KW 66 at 3,750 RPM'.

Markus.

Markus H. wrote:

Check the vehicle registration document! If it says "KW 66 at 4,000 RPM" there, then it should be the old 1Z engine with a wastegate turbocharger. In contrast, the later-installed engine with the same power output but a VTG turbocharger (I am not familiar with the engine code letters) reaches its maximum power output slightly earlier. Then, the vehicle registration document should state: "KW 66 at 3,750 RPM"

.

Hi.

At least for the ALH engine in the Ibiza, that's correct (3,750 rpm).

Hello everyone,

You guys are really great and very helpful. Really great.

I checked the letter, and it says 66 kW / 4000 rpm. According to that, it is likely a 1Z.

Best regards, Franz.

Hi Franz,

Okay, in that case, I would also suggest looking into the 1Z engine.
I have one too.

If I were in your position, I would simply replace (or have replaced) the 'turbocharger wastegate solenoid valve' based on the problem you're experiencing.
Your problem sounds very much like an improperly regulated boost pressure.
I'm not 100% sure about that. I don't want to jump the gun and answer before the real experts in the forum.
However, your problem is quite a common one - my Golf 3 1Z also had it before...
Since the part costs less than 30 euros without installation, I think it's definitely worth trying.

Markus.

Hello,

It's best to double-check your documents. The 1Z engine was only used in the Passat until December 1996.

Hi Markus,

'I have a question about the magnetic valve used for turbocharger boost control. I found a magnetic valve on the front of my engine (my engine is mounted longitudinally). It has two hoses and one electrical cable connected to it. Is this the one you're referring to?' It would be great if this worked!

Best regards, Franz.