1Z Turbocharger Problems: Boost Issues & Solutions (25-08-2008, 19:08)

Hello, as I'm completely at a loss right now, I would like to ask for help in this forum.
I drive a 1994 3er TDI (1Z) with over 300,000 km on the clock. I've owned it for two years, and everything has always worked perfectly. According to the previous owner, the Golf has a chip installed that boosts the power to 124 hp, and the AGR hose is in good condition. It also runs very well and produces quite a bit of smoke, which doesn't bother me. Additionally, I installed an LDA (turbo pressure sensor) last summer, and it indicates a turbo boost pressure of 1.4-1.5 bar. On the highway at 200 km/h, it even shows 1.7 bar.

"Since last week, after the inspection appointment, the turbocharger pressure, according to the LDA (likely a diagnostic tool), briefly reaches 1.3 bar, then settles at 1 bar, and then remains stuck at 0.8-0.9 bar of boost pressure when running at full throttle. I have now acquired a VAGCOM scanner and a diagnostic connector."

The following data were once stored in the error memory when the "old" boost pressure of 1.5 bar was present:

Control unit part number: 028 906 021 Q.
Component or version: 1.9L R4 EDC SG D3A.
Software coding: 00000
Workshop Code: WSC 00000
Sure, here is the translation of the text from German to English:

"3 errors found:"
00519 - Manifold pressure sensor (G71)
28-10 - Short circuit after positive voltage - Interrupted.
00625 - Speed signal.
27-10 - implausible signal - interrupted.
00575 - Intake manifold pressure.
17-10 - Rule difference - Interrupted.

What do these errors mean exactly?


I've cleared the error codes, replaced the boost pressure control valve, and the sensor in the intake manifold is new. I've also replaced the vacuum hoses from the LDA (boost pressure control valve) to the exhaust manifold and the engine control unit. The remaining pressure hoses have been checked and are all leak-free. Right now, I'm completely at a loss as to why the Golf has great acceleration from low RPMs but feels totally choked off at higher RPMs...

An original 1Z engine doesn't have the same mileage as mine, and neither do original AFN or AHF engines...

The Golf has over 300,000 km and still has the original turbocharger, which is now slowly starting to show some minor oil leakage on the intake side.

Here's a log...

THANK YOU IN ADVANCE!

Hi,

It's unbelievable what your charger can handle. Please upload your log file to the forum. Rapidshare says I have to wait 2 minutes to download it...

Best regards, Rainer.

I can't upload anything to the forum, otherwise I would have already done it .

Okay, I'm ready. Please provide the German text you want me to translate into English. Just paste it here, and I will give you the translation.

Is the hose from the turbocharger really properly connected to the control valve? In my case, it slipped off shortly after I replaced the N75 valve and installed it.

You can easily flush out the small hoses using a large syringe (300ml), and while doing so, you can also check the wastegate to ensure it's functioning correctly.

Does the LDA (Linear Drive Assist) match the values from the control unit?

Do you see any oil or similar substances in the engine compartment, especially around the charge air hoses? This could indicate a crack (which might be very small and difficult to see).

Do you have a leak detection kit (LLK)? Have you checked with it to see if everything is sealed properly?

The LLK (charge air cooler) is only 5,000 km old and brand new, purchased from VW. The hoses seem to be tight, with no leaks anywhere. As I mentioned, only the charger on the intake side has a slight amount of oil, and as far as I can tell, the values from the LDA (lambda sensor) match what is shown in VAGCOM. The hoses connected to the valve are also securely attached.

PS: I don't have a button to add attachments .

Does everything always have to have a button?

/viewforum.php?f=40

oh sorry, no button, just a link .

Okay, thank you...


Here's the link with the logs:
Okay, I'm ready. Please provide the German text you want me to translate into English.

The log files have been downloaded 6 times, and no one is providing any information...