sedativeml

So.. I'm likely going to be looking at an 04 A4 3.0 Quattro with roughly 125,000 miles on it that a coworker is selling for dirt cheap (or at least I feel like it's dirt cheap.. $700.) sometime this week or next..

It's been sitting for a year and a half since she bought her new car, and when it was parked I was already aware that it had a few issues that needed fixing.

The few little things off the top that I know of are it needing tires, possibly brake pads, possibly brake rotors and definitely the front bumper cover (not a real big deal, just a little $$$ to throw at it).

Intermittent oil pressure warning which I've done a fair amount of reading on, and the first thing I'd plan on doing is dropping the oil pan and giving it and the pickup screen/tube a good cleaning as well as changing the oil pressure sensor and switching it over to a little thicker oil and oem filter (I believe it has 5W-30 right now) and possibly a seafoam or similar treatment.. Does anyone possibly have a list or point me where I could find one, of what pressures the oil should be at for when I can hook a manual gauge up to it and compare?

Oxygen sensors are the second major thing I know about.. If I remember the conversation correctly (granted it happened over a year ago), I guess the place they bought it from WELDED the o2 sensors in? Derp. Haven't confirmed this is the case nor really thought about how I'd remedy that yet but a complete exhaust system change may be on the list.


Can anyone offer me some more things to look at aside from the obvious major things like leaks, frame condition, coolant and brake lines, transmission, etc?

I figure for at most a for couple thousand bucks and some wrench time I can get a decent little car out of it, if its not too far gone. Last time I saw it, the car was in pretty decent shape inside and outside but I didn't actually go under it (yet) and peak around.

Thanks in advance!

Steamboat

You'll want to determine whether or not the timing belt has been replaced. I believe the recommend change interval from Audi is 100k miles, but from what I've read on forums most people change it somewhere around 70k or 80k miles. If it needs a timing belt, it'll cost well over $1k to have a dealer or reputable independent shop do a full replacement (timing belt, accessory belt, water pump, tensioner, rollers, etc.). Of course, you can change the timing belt yourself for much less, but it isn't a quick or simple task.

Regarding a new exhaust system, you should search the forums, looking for posts about the problems people have had with getting aftermarket catalytic converters to work with their car's ECU, or whatever that module is called. If you live in an area that requires emission testing, this could be an issue. OEM cats are expensive - the last time I looked at them they were something like $1500 each.

If you do buy the A4, the first thing you should get, if you don't already have one, is an Audi/VW specific OBD-II scanner such as VCDS or OBDeleven. It'll pay for itself in a short time.

sedativeml

Didn't even think about the timing belt, thanks! It most likely hasn't been done yet. They said bought it with around 110,000 miles and put 10-15,000 on it then parked it and bought a new car. The used car shop they purchased from fixes them up enough to pass inspection and make a quick buck.

No emissions testing here, I would just want to get it operating how it should with no lights or warnings. I'll have to look for the cat problem threads. There must be a workaround somehow.

I have a pocket scan tool but it's not VW/Audi specific. Is there really that much of a difference between them? I figured just find the code and Google what it says then fix.. I'll have to read into the specific scan tools too.

Luckily I'm the type to read and watch anything related I can find before tackling a project, also it'll just be a second/winter vehicle so I'll be wrenching on it mostly myself at my own pace. That'll save a bag full of cash in itself.

Thanks again!

turbo510

Steamboat gave some very good advice, especially concerning the "timing belt" system, and especially the VCDS scan tool. Your pocket scan tool, if a basic OBDII, will display just the emission-related codes. That Audi has multiple other devices accessible on the diagnostic network, such as automatic transmission, ABS brakes, instruments, climate control, alarm, and so on, which will be much easier to maintain if you can access fault codes or sensor readings from them. You'll need some type of Audi/VW scan tool which Steamboat mentioned.

The timing belt is a big deal if original, because if it breaks, the engine suffers immediate, expensive damage. Belts usually break due to a tension roller or water pump seizing, and at high mileage that can happen. I just got through doing the second TB job on my '05, and takes plenty of time and tools to be done correctly. I am sure that you can find people who will do this job comparatively cheaply, but they probably take the kind of half-assed shortcuts that you can find on YouTube. Besides a decent set of metric tools, including Torx and hex drivers, torque wrenches, ratchets and extensions, you will need to get a set of the special camshaft clamps and crank holding pin, from about $50 on Ebay.

My car has a little over 180,000 miles, and some of the things I've done within the last couple of years are:

Timing belt system (as mentioned)

New radiator

Front control arms replacement

Plastic coolant pipe (under intake manifold) replacement

Fuel pump and fuel filter

Automatic transmission filter and fluid change

This is in addition to the usual tires, brakes, bulbs, air filters, etc.

david9999

Unless you are mechanically inclined, pay a good garage to check for safety related stuff, like front end, steering and tie rods and brakes, then add up the costs of needed repairs and what you can do yourself.
Get a VAGcom and check for codes. If the catalytic converters are bad (an do you have emissions) they are expensive to replace. Copy down all codes, clear them all, and see what may or may not come back.
My suggestion, in order of repair is timing belt (and associated water pump, tensioner, front cam seal) steering and front end parts and brakes if needed. Then, at least your engine wont die due to a snapped timing belt, you can steer and you can stop. Three things I've found very desirable in a car.

Then,
1. Change spark plugs
2 Air filter
3. Change brake fluid with OEM or Pentosin
4.. Flush out power steering fluid with OEM or Pentosin
5. Change transmission fluid
6. Change rear differential oil.
7. Change oil.