New Oppo, New car!

[dieseldub]

Well, it's new to me, at least.

I picked up a 2001 VW Golf TDI 5 speed from a customer over the weekend and I didn't hesitate going about assessing what it needs and beginning to fix them.

First, a little backstory. This car was owned by one customer/friend in the Bay Area, but it spent the last year to year and a half in another mutual friend's/customer's possession in L.A. while he figured out what to do with his own car (ended up getting a replacement engine by yours truly a couple months ago).

So, since his original Golf TDI with a few mods was back in service, he now was looking to return the long term borrowed car to our friend in Berkeley. He already got a newer, bigger car and just told L.A. friend to sell it... asking price all of $1500.

When I heard that and being that I just sold my 2014 Passat (that car's story on the now nuked Kinja-oppo) I needed a reliable, economical daily, not wanting to rack up miles on the V10 Touareg. Plus, the Touareg's front differential is now groaning in protest as a bearing or two is going bad. Besides, 40+ MPG vs 20 or less MPG on my commute...

First thing it needed? A radio. L.A. friend had a Blaupunkt radio of his own in there and had a hard time locating the car's original radio. I told him not to bother since I had a box of 4 OE VW Chinese-market radios that modernize this era VW nicely. Adds Bluetooth, aux in, USB and SD ports on the front, even has a built-in mic. Plus, it LOOKS and fits like OE, which is nice.

Second was the backlighting for the HVAC controls. I happened to have the tiny bulb in stock and fixed that.

Another thing I noticed is that the driver door switch was dead. Common, mildly annoying and not the easiest fix since the microswitch for door open recognition is part of the latch/door lock module. This means disassembling everything in the door and removing the glass and regulator to get to it.

But, I've done so many of these and even had the part in stock, that didn't take too terrible long. Also, the factory VW latch I put in has an upgrade. First photo you see the original switch, you will see how the rotary piece has worn down the plunger on the microswitch:

And here in this photo is the updated part from VW, note the microswitch has a metal lever on it now to prevent the wear on the plastic plunger:

Another thing L.A. friend warned me of, the AC is dead. He had replaced the compressor with a "rebuilt" one that wouldn't come on. He also had the refrigerant removed in preparation of pulling the compressor again to replace it... again. My neighbor at the shop is the one with the AC machine, so I just had him put a vacum to it and recharge it so I could evaluate. I checked a couple basics, fuses, wiring to the ambient temp switch that I've seen chewed by rodents on numerous Mk4 VWs before, all was OK. So, I start the car, switch on the AC, note the one radiator fan is working (the second fan is completely missing for some reason) but the compressor is not spinning. Get the voltmeter out, verify that the compressor clutch is infact getting power and ground. Measure resistance across the electromagnet's coil for the clutch and it's an open circuit. Should be between 3-4 ohms on these Sanden SD7V16 compressors.

Well, the previous, er, user of the car left the old compressor in a bag in the back of the car. I measured the coils resistance and get 3.8 ohms. Perfect! I go about dropping the compressor, removing the clutch plate, the pulley with bearing and then the magnet and switching it out.

Wouldn't you know it, I put it back together, fire it up, hit the AC button, get out and verify the compressor clutch plate does infact engage and spin now, hook up my cheapo gauges and see a really excellent pressure differential:

I grab my stick thermometer, it says ambient temp in the shop was 70, I put it in one of the vents for a few minutes:

Nearly 30 degree drop, I'll take it. I've had slightly colder before, but this works just fine.

Next up, I went to my storage unit to go shopping for random upgrades in my stash. I get a 3 spoke leather steering wheel and a different turn signal/cruise control stalk. The 2001 has the early style where the "on/off" button also doubles as your accel button when you slide it further left. The single button on the end of the stalk is the set and decel button. The later stalk puts a rocker switch on the end of the stalk for set/decel and accel. I always liked that better. I have the part laying around and am removing the steering wheel anyway, why not?!

And now all back together with the replacement steering wheel, which while not in perfect shape is still a lot nicer to lay hands on than the degrading vinyl/foam of the original, plus it drops your thumbs to nearly be at the 9 and 3 positions instead of closer to 10 and 2 like the original 4 spoke. It's just more comfortable to me.

Last order of business yesterday was hacking the convenience control module to get the behaviors I want. Let me explain how the car is setup from the factory;

First, the doors automatically lock as you get above about 10 MPH. I like that and leave that alone. I also have the option of automatically unlocking all 4 doors when I remove the key from the ignition, which is not originally enabled. I change that in an adaptation channel using my VCDS scan tool.

Next up is "selective unlocking." This is where when you hit the unlock button on the remote, it only unlocks the driver door, you have to hit the button twice in rapid succession to unlock all 4. Changing the last digit of the module's main "coding" fixes that. You literally just take the current coding in decimal format and add 1 to the last digit. Now all 4 doors unlock with one click. And that was important to me for my next hack.

Now I put the standard bearer VCDS away and retrieve this old brick of a laptop. A Hewlett Packard circa the late 90s. Why? Because it has a DOS-based Windows system and an old school serial port. And really, I dont need Windows at all. I just need DOS. It's an old program called VDS Pro that I'm using next and it allows me to read and write bytes of data much deeper in the convenience control module than good ol VCDS does. I'm literally flipping a couple zeroes to 1s in a few select bytes to enable a couple items.

First up is enabling the "comfort operation" of the windows to work with the remote. Since the mid 90s even, VWs with power windows you could roll up and down by putting the key in the driver door and turning and HOLDING it in the unlock position to roll all the windows down, twist and hold in the lock position to roll the windows up. Mk4 era VWs were the first ones where this system was diagnostic capable and they all come with a remote fob. So, I flip the right bits and now I've enabled this "comfort function" to work with the remote, too. Now I can roll my windows up and down from 20+ feet away.

The last thing that used to drive me NUTS about Mk4 Golfs and Jetta wagons is that you have to hit the release in the driver door, on the remote or manually using the key to open the hatch EVERY. TIME. The next hack puts the hatch on central locking. So, if I've hit a switch that has told the car to unlock all 4 doors, I can now open the hatch as many times as I want until I lock the doors. I don't have to press the release every dang time. As it SHOULD have been from the factory. Apparently they are programmed that way from the factory for the European market, but I guess they figured the U.S. is too crime-and-lawyer riddled that we should be given this extra but of "security" that also just makes it more of a hassle.

That was my weekend... well, half of it, anyway. Car showed up Saturday evening after 4. Spent a few hours on it then, came back early afternoon Sunday and did the rest then. The next things on the list include a new thermostat, it won't hold temperature, never gets to 190 even with the highly buffered gauge in the cluster. I also have no history of when the timing belt was last done, but the belt does look good, but it's one of those deals where some labor and materials could be shared... which brings me to my next idea to tie the next phase all together. New timing belt, water pump, thermostat and, while I'm there with the belt off, might as well put a bigger injection pump on it for a little increase in fueling and injection pressure.

Eventually will need a new clutch and flywheel. It appears to have a dual mass flywheel still. It doesn't vibrate yet, but it does make the occasional clunk. Also not a bad job on one of these. Parts are cheap compared to the newer 6 speeds too, and there exist OE parts to convert to a less problematic single mass flywheel. So why not?

I love these mk4 diesels. They're easy to work on, easy to track down electrical issues since it's not overly computerized, but is computerized just enough to be easy to use a scan tool like VCDS to quickly pinpoint the problems, and they're easily hacked to change behaviors to what I personally want.

Beyond that, it needs a good set of new seats. Hoping to make a score at Pick n Pull... something leather and heated.

[CB]

@dieseldub I learned how to drive stick on a Beetle and Jetta diesel of this vintage. I’ll always have a soft spot for them. Awesome work.

[jminer]

@dieseldub I love your dedication to the TDIs. As the now 2 year owner of a MK6 I get it - they're pretty special vehicles.

[WhoIsTheLeader]

I'll always like styling and design of 2000s VWs. I'm especially intrigued by the diesel Golfs and Sportwagens, though I don't see myself owning one this old. Good on you for showing an old VW the love it deserves!

[spacekraken]

@dieseldub This is extremely cool (no pun intended with the AC). I still haven't seen one of those cruise control stalks, think we were talking about it on discord a while back. Seems like a really nice implementation of CC (the rocker switch you swapped in).

Still looks super clean for 300K!

[dieseldub]

@spacekraken Kinda funny how many of these I've owned.

I've never had a mk4 sedan, but I have had a 2000 Beetle TDI. Two 99.5 Golf 2 door, crank window TDIs and two 2003 Jetta wagon TDIs, all with the same ALH code TDI.

Specifically talking to the Golfs. This one at 290,000 is actually the least miles of the 3 Golfs I've owned. Lol. The previous 2 were above 300,000 when I had them and eventually sold them.

And this is the first 4 door Mk4 Golf I've owned and first with power windows.

The Beetle and the two wagons were power.... and less miles. Though still above 200k for each.

[dieseldub]

@cb said in New Oppo, New car!:

@dieseldub I learned how to drive stick on a Beetle and Jetta diesel of this vintage. I’ll always have a soft spot for them. Awesome work.

I learned on my dad's 98 Mk3 Jetta diesel be bought new in 98... and I eventually bought off him in 2004 with 192k miles on the clock. That's the car that started me down this silly path to VW diesel addiction.

The mk4s are definitely much more refined than the mk3, but I still have a soft spot for those ugly, boxy things.

[spacekraken]

@dieseldub haha awesome! Those jetta wagons have aged super well, would totally daily a TDI or VR6 if one came across my radar up here and I had the space.

[chan]

This is quality VAG Oppo.

[Stef Schrader]

Ooooooh, I like these.

[RallyDarkstrike]

Nice write-up! The 'car-hacking' part is very cool!

[RacinBob]

I hate how easy you make it look. I would require a weekend to disassemble the door, only to never have it function properly again. Had you charged yourself shop rates, how much would you have thought all this would have cost?

[Qaaaaa]

Very nice. I can't remember, are these emissions exempt? I kinda want to snag an ALH car and drop that drivetrain in my Rabbit.

Isn't it nice to have almost all the parts you need to fix a car just laying around? I'm about $1100 into my Jetta counting the car itself, thanks to hoarding.

[dieseldub]

@qaaaaa they USED to be smog exempt in California. All diesels were until California changed that rule in 2010, and they retroactively applied it to 1998 model year and newer diesels. So people that had these from new spent almost an entire decade not having to smog them, and then suddenly did have to smog them.

[dieseldub]

@racinbob good question! Probably $120 labor for the door latch/lock. Part itself is a $200 part.

Everything else being used parts, I'd have to go find what I paid and maybe put a small mark up on. Used steering wheel WITH air bag I wouldn't let go for less than $100, even being in not perfect shape. The used stalk might be $50, not sure.

The radios I sell for $150, which is extremely cheap for an OE head unit.

Backlight bulb for the HVAV is only a couple dollars and took only a minute to replace.

Labor-wise, it likely would have been close enough to $500 for everything I did. The compressor is a weird one, though. I was willing to take a chance on random used parts and unknown "rebuilt" quality part that was already in there. If it were a customer car I'd likely say they should buy a new compressor if they expect me to warranty the AC work should there be any issue. Oh, plus spending $100 to have the AC discharged and recharged.

[RacinBob]

Yep, that is the deal isn't it. There's not a lot of material cost between a worn out car and a good functioning one except for finding the expertise that you can afford. For the average mortal strolling into a dealer, my bet this was a $2k day which would be hard to justify unless they had a shop like yours. May it deliver many happy miles.....

[dieseldub]

@racinbob Very true. When I know there's a strong likelihood that a good used part will get the job done, I give many customers the option, but also warn that there's a higher possibility the cheaper fix may not work.

I have been burned before by offering to replace an obviously bad electromagnet on a compressor only to find out the compressor just wasn't working as efficiently as it should either, at which point you would just throw in the towel and say it needs a new compressor anyway. But there's no way to evaluate how effective a compressor is until you have it at least engaging the clutch and can read what the pressure is doing on the high and low side.

But this was an unusual case where the compressor was supposedly "rebuilt," meaning I hope they at least cleaned it, oiled it and replaced the common failure point in these: the refrigerant control valve. But they obviously didn't catch the fact it had a very dead electromagnet so who knows what else they overlooked.

But, I got lucky. Parts are readily available for these cars, plentiful in Pick n Pulls locally and since I do my own work, the cost of ownership is quite low. Most of these problems aren't expensive for me to fix for myself. I can keep on of these going indefinitely with not a ton of money for a long, long time. So super familiar with all their common issues and cheaper ways to go about fixing them and preventing some of the other common failure modes. And compared to more modern cars, these are pretty stone simple and easy to fix. I have a hard time saying no to a cheap one that runs and drives.

[RacinBob]

Yep, I just admire how mechanics make stuff look easy. My buddy John is a Honda mechanic and he'd stop over with a small bucket of tools and 45 minutes later would have pulled and changed the head on my race car.

Another thing is It's like the car knows its not worth fighting him and just give in. For example there is a spring driftpin that holds the shift linkage together. He gets it out with one hit. Meanwhile for me not only does it take me ten minutes to get it out with the same tools but usually I end up having it sailing half way across the shop when it comes out......

You probably took the head unit out of the dash in 2 minutes. Me, 2 hours and scratched the dash for life is what it would take me. and that is after watching somebody do it on youtube,.

[Albino Kangaroo]

@dieseldub Great post! As a 1999 Golf GLS owner I am very interested in the chinese version of the radio. Is this something that can be found on eBay? Is it generally plug and play? I am currently rocking the tape deck adapter. Car has the 6 CD changer in the back. I've read up and to use the CD like an Aux in requires an adapter and is a bit of a hassle.

Does it receive US stations?

[BunkyTheMelon]

@dieseldub Nice write-up!!!

[dieseldub]

@66p1800inpieces I've been buying them from AliExpress... (I know...)

Search there for "RCN210" and make sure it's the mk4 version, not the mk5 (mk5 will have bolt tabs sticking out and the faceplate isn't so perfectly square).

Very cheap there, though shipping bumps it up a fair bit. Since yours doesn't need a different adapter like the mid 2002 and up cars, that saves a couple bucks as well. The radio should come with an adapter for your older ISO connectors. I generally have been getting them from the vendor "Bodenla". Also has an antenna adapter that is simple and works well when adapting to an earlier mk4 like ours.

As for stations, yes. FM is actually interesting because it tunes EVERYTHING, not just the "odd" stations. Most American radios go from, say, 88.1 and the next station would be 88.3. This one would do 88.2. Does odds and evens.

The AM tuning is the one weird part, other nations use a narrow AM band than we do. So there are some stations on the extreme low or high end of the U.S. rang it won't tune to. I'll have to double check what the max range is on mine and report back.

[Albino Kangaroo]

@dieseldub said in New Oppo, New car!:

RCN210
This is great. I was looking at the one on ECS tuning a year or two ago but it retails for $650. The Aliexpress one looks the same. I only plan on having the car for another year (moving) so while I would have already bought this a year ago now I have to think about it. With COVID I don't really go anywhere.