the second project for saturday was to get some work done on the car and to get familiar with it.

So I my standard tasks for new to me cars

• differential oil change
• engine oil change
• transmission oil change
• transfer case oil change (new one, never had a 4x4 before)
• air filter

Well I tried todo this all, but took to long and only managed to oil the engine (twice, I overfilled...) and the differentials. At least it makes it easier to diagnose possible leaks after the changes...

Now for some reasons people always remember to replace the engine oil, but barley bother with the differential oil for some reason.

I don't know why!

I mean this is a differential

quite a lot of tiny parts and gears, which all want to be lubricated and over time generate tiny tiny metal shavings. These accumulate on the magnetic drain plug.

And look like this

For a comparison, the same plug looks like this after cleaning

Now how complicated is it to change the differential fluid? Well all you need is a 10mm square drives, oil catch pan and a pair of ramps.

and maybe a light, but this is optional. HIghly recommended is the wooden mallet, most useful tool I bought so far...

One tip I can give, do not use a fill nozzel! They tend to get loose and drop into the differential. And trust me, it's a major pain to get out. Since you only have 2 little holes to work with...

this is the fill nozzle after I recovered it 2 hours later and making impromptu fishing poles out of metal springs and wires...

Now what does this actually save me?

Air filter change:

20$ Garage vs 8$ Me
Engine Oil change:

60$ Garage vs 35$ Me (would had been 15$, if I had done it right to begin with)

Differential:

200$ Garage vs 50$ in oil and lubricants (would had been 30$, If I hadn't dropped the damn nozzle into the differential)

The sad part is, I still need TODO the transfer case (90$ Garage vs 15$ for oil) and the transmission oil (120$ Garage vs 70$ Oil). I guess I do this next weekend or as soon as I manage to get the correct transmission oil...

Now the big question is, what is actually wrong with the car?

• one failed O2 sensor - 20$ part (garage charges 200$ to change it)
• one failed Knock sensor - 30$ part (garage charges 600$ to change it)
• valve covers gaskets are seeping a bit oil - 100$ part (garage charges 1000$ to change it)

I will monitor how much the valve cover gaskets seep and replace them by myself if required. Don't really worry about the Knock/O2 Sensors at this point in time.

The O2 sensor is only needed for emission tests and the knock sensor helps protecting the engine and alters the timing in case of bad gasoline. Means I have to buy good gasoline and so far I did not hear any knocking or pinging and the car runs incredible smooth (except for my poor shifting skills)

If I have the feeling I need to replace the sensors I'm going todo this myself in an afternoon or two. After the passat disaster I have now all the tools I need, or friends from which I can borrow the missing ones.