Bought a B4 TDI cheap

Hi Folks,
I picked up a 96 B4 TDI on a few days ago and towed it home.
Owner go tired of it going into limp mode and bought a Suzuki rollerskate car. I ran VCDS and got several codes but the important one is 00575.

I have not driven it yet because he parked it when the left brake rotor 2 round halves separated like an Oreo cookie. Never saw this before so that will be one of the first steps to getting it back to mechanical usability.

There is an exhaust leak near the exhaust manifold. I have not tracked that down yet. I can hear the turbo whining so its spinning free.

I will check the N75 for voltage and Ohms in the next couple days and see what I get. Hopefully it is the problem and a swap will get it back to having normal turbo operation. Of course, the waste gate actuator will need to be checked also.

It should run OK with some tinkering.

The bad, its rusty and the interior is marginal. Im sure the other typical B4 issues will be there with windows/doors. The sunroof is screwed up also. I did move it manually with the emergency tool. Its closed.

Came with 4 studded snows and 4 good summer tires. It has Alum. wheels too.

At 212k miles I think it can be save from the bone yard but before I even consider any major body work or paint it has to be running sound.

Thoughts?
Thanks.............JJ

For the pressure difference code, I'd start by replacing all of the 3mm tubing. If it still has the crimped on metal clamps, it's likely never been done. Remember to do the one inside the ECM as well.

Shortly after I got my car, the first problem was 00575. A quick google search suggested I replace the 2 inch section in the ECU. Went to Napa, bought a small rubber hose, swapped it out, CEL disappeared. Hasn't come back for that yet.

Like Mcgink said, swap all the small diameter hose. The silicone stuff really is great. The sidewall of the tubing is very thick, should hold up very well.

I'm gonna assume you're knowledgeable enough to know what a boost leak sounds like, so I'll believe you when you say that's what it is. If I were you though, I'd check the turbo out. See if it's leaking oil and see how much shaft play it has. My turbo failed on me last fall at ~153k miles and for a while just before failure, the turbo made a more pronounced whine. It sounded more like a supercharger than a turbo to me. The oil seal was giving out and the turbine was rubbing the housing which I'm sure is what the noise I was hearing was. But it doesn't hurt for you to at least check for oil in the compressor and shaft play.

Good luck with the new to you B4, it sounds like you probably got a good deal.

Thanks for the replys

Thanks for the replys guys. I checked the N75 today after work (working alot these days). Voltage to the N75 is there. Bently says Ohms across the N75 should be 25-45 Ohms. NOT! it turned up to be 2-3 Ohms.

So, Is this a reliable test of the N75? I have not done this before.

As far as the tubing connections, they are original and in very good condition. Im surprised based on the other indicators of maintainance.

Thats where I will start. I do have the red and blue tubing from Mcmaster Car. Nice silicon tubing.

On the good, I was comparing my great running 97 B4 and found a broken vacuum line near the battery. Repaired. By the way, what do the vacuum lines do that go next to the battery by the fender. I have not tackled that and wonder what that vacuum line is for. Its hard plastic and then rubber hose at points. I think it eventually goes through the fire wall to do something?

Have a great day folks...........JJ

00575 is the worst. It can be so many things.
What does the code say exactly? That narrows it down sometimes. Is it "control difference," limit exceeded, or not reached?
The other guys are right. Even if the vacuum hoses look virginal; if they're original replace them. I've had a one way valve go bad recently too so replace that for .73 cents as well.
If you have two of these cars now (a common affliction amongst us b4 owners) buy an extra n75 valve just to test. The ohm thing and spraying oil in them and doing a magic dance for them just makes you run around in circles. Get a known good one, have it on the shelf and if it goes into limp mode you can rule it out immediately.
Pop the hose off the top of the intake and look in there. Make sure it's not all clogged up. That will throw 0575. The vanes in your turbo could be dirty too. Too much oil in your intercooler. Check the vacuum connection right at where it comes out of the booster. Make sure that nipple is secure, no wiggling at all! Could be A boost leak somewhere (you'd hear this one as a whistle). Could be A really dirty and clogged catalytic converter. Fun list, huh. Oh, yea... I think a bad maf will throw this code as well.
Anyway. Replace the vacuum hoses already! Have you done it yet? You should. Then go down the list depending on the sub-category of your 0575 code. You'll get it. Eventually...

The vacuum line near the battery that you're talking about controls the recirc door for the air conditioning.

Thanks so much

I appreciate all the info. Im in the process of getting a new N75.
I ordered new rotors and pads for the front too. Got a crazy deal on rotors. I dont know why but they were only 9 bucks at autozone locally.
They honored that but when I tried to get more later they corrected the price. Go figure . I got lucky there. So, Brake and rotor change out was 43 bucks, I'm liking that.

Next is N75 change and it will be driveable. Then the fun begins.

On another note about my 97, much thanks to the reply on the vacuum line that goes by my battery. Now I know why my HVAC has been screwed up. It has been puking pieces of foam out the vents and I guess the problem with the typical B4 HVAC is creeping up on me.

Ok again much thanks for your replies and guidance. I will update when I have time.

You all have a wonderful day.........JJ

I got a new N75 valve from metalman. Checked the ohms across it and its 30 ohms.
Obviously better than the 2-3 ohms I got on the one in the car. Will change and advise the results.....But, I'm sure I will need to get under the beast and lube/check on the actuator and its movement. Will post results but it will be awhile.
Working 72 hrs/ week right now so I only get about an hour to tinker in the evenings.
Will post.........C Ya

On the other car (97). It developed a fuel leak on the inj pump. I will post asking for advice on that. Thanks

Update

Replaced all the front brakes except the flexable hoses. Breaks work well now.

Replaced N75.

Crawled under, found down pipe very loose at turbo. Drove it about a mile. Will not boost at all. I can hear the turbo spooling up but I'm pretty sure the waste gate is stuck open.

I think I will attack it from the top down when I get time. Cant get my big hands up in there from the bottom.

Thanks

Unbolt that big block weight and cut off the arms that secure it to the subframe. Lots more room afterward.