N53 Steam from exhaust

[carbon83]

Hi all,

Looking for some advice. I have a 2010 N53 engine and recently, it has been running a little rough at start up. I thought that this was down to the cold weather we are currently experiencing. The car seems to vibrate quite a bit when starting off and when reversing when cold.

Anyway, I have noticed that the amount of smoke/steam coming from the exhaust seems pretty high. I know the N53s are known for being steam engines but I think it is a little excessive? Again, I know we are experiencing cold weather but appreciate some thoughts on this before I get it booked in…

The video below shows when the engine has been driven for 30 minutes or so (so is up to normal temperature), ambient temperate is showing 5 degrees Celsius. The car has done 80,000 miles and according to BMW, the coils when changed in 2012.

https://youtu.be/Wb0Qo_5EcFQ

It’s the same amount of smoke whether it is on a cold start or when the engine is up to temperature like the video.

Thanks!

[eybic]

I don't know the engine but I'd be leaning towards it being normal. The temperature difference between the air and what is coming out of the exhaust will be quite significant, causing condensation/ steam. Think of it like being able to see your own breath on a cold day. I certainly wouldn't say it's smoke.

[bmwmike]

Seems a lot but as said,probably normal. Mine chucks out a fair bit too. If it does a lot of short journeys there'll be water in the exhaust pipe too, probably.

Is it losing coolant? If not I'd not be concerned

Misfire when cold is probably an injector leaking and you should really investigate that. My n53 (60k, 2012) is rock solid from cold start even if it's been sat for a few days.

[carbon83]

Hi guys,

Thanks for the replies. No, it is not losing any coolant. Engine oil consumption and coolant consumption have both been fine.

I am wondering the rough start / rough when reversing when cold could be down to some old spark plugs still in the car? The next service is due soon which will require a new set of spark plugs anyway.

[HM-2]

Direct injection engines always tend to be very steamy. I've always assumed it's a product of higher EGTs due to either lean burn, or it actually being able to approach stoichiometric efficiency.

My EA113 turbo DI Leon was the same, as is my B58 DI M140i.

[bmwmike]

HM-2 said:

Direct injection engines always tend to be very steamy. I've always assumed it's a product of higher EGTs due to either lean burn, or it actually being able to approach stoichiometric efficiency.

My EA113 turbo DI Leon was the same, as is my B58 DI M140i.

Good point! I've noticed that also.

[mike9009]

Hi

I have an N53 engine and mine seems to produce roughly the same amount. There is even a surprising amount when my engine is warm.

Mike

[bmwmike]

I think the reason may be because the n53 can operate in a variety of lamda ranges from 0.5 to 2.5 as it switches from stratified to homogenous injection modes, the exhaust temperature varies hugely and also the volume of expelled / unburnt inlet air also has an effect because air contains moisture. Depending on the temperature of the exhaust that moisture will condense and accumulate or immediately turn to steam it vapour. Answer is to keep engine revs over 4000 and maintain load to keep engine in homogenous mode and blast out the exhaust

Interesting read:

https://www.newtis.info/tisv2/a/en/e87-120i-sha/wi...

[to3m]

Fascinating bit at the end there regarding desulphuring the NOx cat:

https://www.newtis.info/tisv2/a/en/e87-120i-sha/wiring-functional-info/power-train/engine-electronics-quality-control-valve-msv/X9wy9Ir said:

The following vehicle operation is required for active heating of the nitrogen oxide catalytic converter:

• Driving speed over 110 km/h for 25 minutes
• Fuel tank level greater than 50%

Those are actually quite onerous requirements! 110km/h = 70mph. You'll need a motorway rather than a dual carriageway if you're going to get an uninterrupted 25 minutes of 70mph, but even without any roundabouts, what are the chances you'll get that?

I wonder how many people's cars simply never end up being driven under those conditions?

I bet this basically never happens in my car, that's for sure. The longest journeys I do at all regularly that have a significant 70+mph section are me driving to see family. 60 miles in total, of which 35 miles are on the motorway - i.e., 30 minutes at 70mph. Better hope I don't have to brake, or there's a very good chance that's my 25 minute window gone.

[bmwmike]

Ha, never thought about it that way. Wonder if that's why the oem NOx sensors fail - they get bored!

Curious that it's vehicle speed rather than engine speed?

[bodhi]

Don't know of the specifics of the N53, but I can tell you that every single 6 Cylinder petrol I've ever owned, or my family has owned has done this in cold weather. I'd had it explained to me as a combination of hot exhaust gases and the heavy duty exhausts BMW fit that means they take ages to warm up - hence the steam.

[mahoone]

My 330i N53 is the same in this weather (around 0 degrees).

[carbon83]

Hi all,

Just thought I would update this topic if anyone else has similar issues.

So a couple of days after starting this topic, the EML light came on and the car was running really rough so booked the car into a BMW dealership.

They came back and said that 2 cylinders are misfiring and after various checks, concluded that all 6 injectors needed to be replaced. In addition, the NOX sensor needed to be replaced.

Thankfully, this was all covered under warranty (estimated cost of the work was at £2.5k!) and I picked the car up today and wow, what a difference! The engine feels so much more responsive!

[bmwmike]

Good result

That's only 2.5k at dealer hokey insurance claim rates