AHF startup behavior now significantly improved! - read :-D

I just wanted to give you a little something to think about.

I bought a brand new, original VAG starter motor on eBay before Christmas (for €30.00 ), and I installed it after Christmas, while also completely cleaning and polishing the positive and ground cables. This included cleaning the ground point on the transmission, the flange surface on the transmission for the starter motor, and the ground point on the car body. That there was still electricity flowing is amazing...

Although the starter motor speed was still within acceptable limits with the old starter, and the brushes, rotor, etc. were still in good condition in the old starter, the vehicle now starts after the turn as never before .

I compared the starter motors (old and new) while they were removed, using jump cables and a fully charged second battery, and even then, a significant difference was noticeable! And yet, despite the fact that the storage, the carbon brushes, the rotor, and all the other components in the old starter motor appeared to be in good condition. (The performance data of both starters were the same, both were Bosch 2kW).

Too bad.

You swapped both dimensions (contacts and starters themselves) at the same time.
So, there isn't a test like "new starter with rusty cable" or "old starter with cleaned contacts"?

We don't know how much each thing is worth now.

m;

Yes, that exists, because I actually "did" that.

Let's sort it in a non-chronological order, because after "corroded," the next word is "cleaned" .

old starter motor with corroded contacts --> fair condition.
Old starter motor with cleaned contacts --> better.
New starter motor with corroded contacts --> better, similar to position 2.
New starter motor with cleaned contacts --> significantly better.

"New starter motor with jump leads connected to an external battery --> performs worse than when installed in its original state with cleaned contacts, but better than when installed with corroded contacts."

Old starter motor connected to an external battery using jump leads --> better than in its installed state with corroded contacts, but worse than if it were installed with cleaned contacts.

Are you satisfied, Martin?

PS: Unfortunately, I didn't measure the individual operating speeds for each state, but the combination definitely worked!

Sure, you're welcome.

Then I will put my 4-year-old contacts to work.
Because replacing the battery (with a good, working BMP battery) didn't make any difference.

m;

I completely removed the cables, including the ground cable from the chassis side, which VW advises against, but I don't have any issues with that; it was just as dirty. The worst part was the constant power cable at the starter. The ground cable was attached to a bolt that connects the transmission to the engine block. I removed that bolt (there's still an 8mm stud for the cable and a 13mm nut on that 19mm head), and I cleaned the cable connection point and the surrounding area, as well as the area around the hole in the transmission bell housing where the wide part of the bolt head sits. The second area was under the battery box. The threads of the transmission bolt were almost completely free of corrosion, as very little gets there. I cleaned the inside of the battery terminals with stainless steel wool. I replaced all the nuts. (These are nuts with a ribbed collar.)

I think the most likely culprit is the positive connection directly on the starter motor. After assembly, I lubricated every joint with Russian machine grease, so corrosion is a thing of the past...

Level 2

Are there any photos?

"I used to not even know what an Inge-Neuer was, but now I'm one myself!"

Unfortunately, I didn't take any photos. The corrosion was so severe that I would only describe approximately 30% of the surface area on the contact points of the cables as "brass-colored," and that was only in the areas where there was still direct contact. The rest, to put it bluntly, looked like garbage. I initially tried to brush the cables while they were still connected, but I gave up after a minute. I then removed them and clamped the contact surfaces in a vise, using a wire brush to verschandeln them until they were shiny and sparkled.

I can only provide photos of the finished result if you would like.
What is Level 3? I'm already excited!

Deus Violentia wrote:

What is Level 3? I'm already excited!

Disconnect the cables again to check for corrosion between the strands and the cable lugs.
You can achieve this by simply sending approximately 5 amps from a DIY power supply and measuring the voltage drop between the crimp terminal and the wire strand using a DMM (with mV resolution).
If, for example, a similar amount of voltage is lost on this 1 cm as is lost on the entire remaining length of the stranded wire between the cable lugs, then you have found the next problem area(s) .

'Normally, simply loosening and re-tightening the fittings should help, as the threads of the nuts will re-engage with the brass.'


Alternatively, I've been thinking about adding an extra power wire for the starter.


'After I increased the compression of my homemade car's engine ('a little' more, from 10.5:1 to 12.x:1), the starter motor sometimes struggled to crank it over. The interior lights dimmed almost completely, even though the battery showed 9.5 volts at the terminals in the back. This was despite using 35mm² cable (which should be more than enough for a small 1.4-liter gasoline engine). Then, I tried connecting a second 'ground' connection using two jumper cables, and lo and behold, the engine cranked like a champion.'

Connecting the battery to the metal involved a 20cm piece of 35mm² wire with soldered ring terminals, which was then connected to the nut of the seatbelt buckle.

@ Ulf: I had seriously considered doing it, but I couldn't because I didn't have a multimeter on hand while I was working on it. I'm not going to take that wire apart again anytime soon. After a visual inspection, the press connections still looked good; there were no signs of woodpecker damage or anything similar.

@ Stummel: Based on the current situation, I strongly believe that the whole thing has served its purpose very well. However, when I have the time, I will supplement the wiring with jump start cables (from the vehicle battery to the starter motor + and the transmission bell housing) and see what happens. However, I don't expect to see another "improvement phase" from this.

I only posted this here with the hope that someone might benefit from it.