ammoun

Hi,

I had an oil leak that started after I replaced camshaft magnets and it seems like one magnet on the driver side is leaking oil but I can't reach the bolts behind the power steering reservoir.

Anyway, the oil level dropped twice and I had to add some twice in the last 2 weeks. Often white smoke comes out of the hood with a bad smell.

Yesterday and today, when I start the engine in the morning, a very thick white cloud that seems odorless comes out of the exhaust, also the RPM was unusually going up and down and I noticed that the engine noise was thicker for few seconds...

After like 15 or less seconds, the smoke became normal and so does the engine noise.

Last night CEL came on with p0170 and p0173.

Any clues please?

Thank you

insame1

White smoke is normally water. blue/black smoke for oil. Did you check for any mixing?

ammoun

I did check the coolant level but I can't tell for sure if it's missing at all, right now it seems normal to me so I can definitely tell in the future if the level goes lower. Any other way to diagnose that hypothesis? Thanks

insame1

Not really. May be check your trans fluid too. Also please update your user CP. I dont fix BMWs

550x2

White smoke is a blown head gasket. It might just be starting to go and will get worse quickly. The smoke is coolant entering the cylinder and may not be entering the oil system so that is not a way of knowing if the gasket is leaking. It will soon look like a Cheech and Chong movie with all the smoke! Get it repaired before it warps you head. I mean the cars head, not like a Cheech and Chong warped head!

ammoun

So it seems like the smoke only happens when it rains... Let's ignore the smoke part for now until I learn a pattern for when it happens.

My bigger concern is P0170 and P0173, they came back soon enough after I cleared them.
What can cause a fluctuating RPM on cold start and the hesitance while warming up?

Glyn M Ruck

P0170 Fuel Trim (Bank 1)
P0171 System too Lean (Bank 1)
P0172 System too Rich (Bank 1)
P0173 Fuel Trim Malfunction (Bank 2)
P0174 System too Lean (Bank 2)
P0175 System too Rich (Bank 2)

You have fuel trim issues. Check your MAF & that the MAF is clean. Ensure that your temperature sensor is good or the ECU can't control fuel trim for temperature. You might not be achieving stable open loop mixture enriched when cold!

ammoun

Glyn, I'm assuming that I need a better scanner to get 171, 172, 174, 175?

Actually, in the past I remember whenever I forget to connect that one hose that attaches to the rear engine cover, after like 10-15 miles I get the P0170 and P0173.

But I know this time that it's not the case and I can almost tell from the smell and the mpg that the system is too rich.

Should I get a better scanner to read the more specific errors? If we assume that the system is indeed too rich, where should I focus on please? I guess air leaks in the hoses as a start but I'm only aware of the one that connects to the back engine cover and a tiny one close to it. I inspected both and don't see anything wrong.

insame1

Maybe try what Glyn suggested. Also your best bet for scanning is to take it to someone with a star scanner.

ammoun

The temperature sensor in my opinion seems to be working fine as I had a thermostat problem in the past and I had seen then the gauge struggling to maintain the temperature and drops as soon as I turn the heat on in a very cold day so these are indications that the sensor is working in apparently the right way.

The current situation after thermostat change, the temperature can be maintained at slightly above 80 and it requires around 3 miles to reach ~80 from a cold start. I'm just thinking these are signs of a good working temperature sensor/thermostat... I hope that we're talking about the same thing.

I just visually inspected MAF and I couldn't see any dirt or anything, don't know how the diagnose the ECU issue mentioned though.

Glyn how would you proceed in this case please, if I'm missing tools just let me know and I'll see what I can buy