Hey guys, i just joined this forum a couple days ago but have been lurking for a while looking for possible answers about the issues im having. My a4 decided to die about 3 months ago, and its been a project ever since. I took it to a shop to get the codes and they are as followed:

16500
16514
16845
17512
17920
18014

I replaced the plugs, wires, redid the vacuum lines, and replaced the solenoid valve(N156 i believe). The car runs well for a few minutes, then it seems to lose power and fluctuate from 500-700rpm and sounds like its about to cut out. Im also getting white smoke from the exhaust and some liquid there too. any help would be much appreciated, as i am new to fixing my own car.

 

White smoke is very bad. It usually means a head gasket took a ****.

16500/P0116/000278 - Engine Coolant Temp. Sensor (G62): Implausible Signal

Possible Symptoms
Starting the engine when engine is warmish or warm, idle rpm immediately is 1200 - 3000 rpm.
Diesel: an indication is extreme long time burning time of the glow indication light.
With all engine temperatures seldom idle rpm will vary between 900 - 1000 rpm.
With engine warm (90 °C) the engine temperature suddenly drops (70 °C) and slowly comes back to 90 °C.
Possible Causes
Wiring and/or connections faulty
Engine Coolant Sensor (G62) faulty
Possible Solutions
Check wiring and connections
Replace Engine Coolant Sensor (G62)

16514/P0130/000304 - Oxygen (Lambda) Sensor B1 S1: Malfunction in Circuit

Possible Causes
Oxygen (Lambda) Sensor Heating Bank 1 Sensor 1 faulty
Possible Solutions
Check Oxygen (Lambda) Sensor Heating Bank 1 Sensor 1

16845 - No Idea

17512 - No Idea

17920 - No Idea

18014/P1606/005638 - Rough Road/Engine Torque Signal from ABS: Electrical Malfunction

Possible Symptoms
Malfunction Indicator Light (MIL) ON
Possible Causes
Wiring and/or Connector(s) from/to Brake Electronics faulty
Possible Solutions
Check Wiring and/or Connector(s) from/to Brake Electronics
Special Notes
May be stored in Combination with 01203 in Brake Electronics.

If I were you, I'd make sure you don't have a blown head gasket before you chase all of these things down, because like I said: White smoke almost always means bad head gasket.....especially if you're losing coolant and it's not spilling onto the ground.

G/L w/everything & keep us posted.

 

They told me 16845 was fuel level sensor 19720 is intake manifold valve(N156) short to B+ and 17512 was B152 volt too low

I do have some fuel injector cleaner in the gas tank from a bad fuel injector that I ended up replacing. Would that also cause the white smoke? Saying that, Should I go ahead and replace the rest of the injectors? I'm hoping to rule out bad gaskets cause it will be a pain to do lol but if it comes to it I'll have to replace them.
I did also notice that when the engine warms up is when it loses power and the coolant hoses get unusually hot. I'm planning on flushing the coolant and replacing the res cause it's cracked. Hopefully that will help?

 

I wouldn't worry about the fuel and/or injectors. If you had a problem with fuel, you'd either see black smoke, or you'd hear detonation/extreme loss of power. You wouldn't see white smoke though.

Fuel level sensor is a separate issue. I wouldn't worry about that yet.

I don't know anything about that 17920, but it looks like it's worth looking into further, but also might be something a head gasket could cause. I don't know.

Your 2nd to last last sentence: "I did also notice that when the engine warms up is when it loses power and the coolant hoses get unusually hot."

That also screams "Head Gasket".

The best advice I can give you is the "Hail Mary".
1. Flush your cooling system (proper) 3 times in a row, with regular (preferably distilled) water. Don't forget to leave you heat on max high (temp and fan).
2. Fill your cooling system back up. You can use anything from straight distilled water to as much coolant as you want. Anti-Freeze is just that (it keeps the water from freezing in the winter).
3. Buy the best (not necessarily the most expensive, but the best) "Head gasket stop leak", or whatever the ****'s called. You'll know it when you see it. It should be by the "coolant stop leak".

Drive your car around for a few days and every morning (after it has cooled down, check your coolant level. If it's low and there's no coolant on the ground underneath the car, then it's almost definitely a head gasket.

If that's the case, then put in the stop leak **** (as directed) and see if it does what it's advertised to do. If it stops, or slows the smoke and cools the radiator hose, then you know 100% for sure that you have a bad head gasket.

That's the cheapest way to diagnose one of the most expensive/biggest problems on your car.

G/L