Monumentous amounts of white smoke...

S

Sheikh Unvac

Member
Evening all,

Any assistance here will be greatly appreciated - my pride & joy currently finds herself in a bit of a state...

2006 N52 - Si sport
70,000 miles
Mostly used for short jaunts to the train station

This morning, on pulling away I looked in my mirrors to find myself followed by plumes of thick White smoke and an acrid smell. I coaxed the car a mile home later in the day, still followed by White smoke and now the introduction of the Amber oil warning light on the dash.

Signs and symptoms:

- lots of white smoke
- acrid, burning smell
- exhaust tips now black
- oil light illuminated
- small amount of mayo in the oil cap
- coolant level low, looks clear
- sounds like a tractor
- seems to have lost oil
- not overheating, temp gauge under 90 degrees

I'm hoping someone here with a better knowledge of mechanics and the engine might be able to advise what the **** could have happened.

Thanks,

Matt
 
Yes that can cause a loss of oil.
other culprits could be the headgasket, worn piston rings or worn valve stem seals. But those are not common on low mileage cars and a clogged pcv is, especially when its cold and when the car is only used for short drives.
I think the low coolant level and mayo on the oilcap are more to do with the constant short drives, but that could also be an indication of a headgasket problem
Do you have a heated garage?
 
GuidoK said:
Yes that can cause a loss of oil.
other culprits could be the headgasket, worn piston rings or worn valve stem seals. But those are not common on low mileage cars and a clogged pcv is, especially when its cold and when the car is only used for short drives.
I think the low coolant level and mayo on the oilcap are more to do with the constant short drives, but that could also be an indication of a headgasket problem
Do you have a heated garage?
Click to expand...

No heated garage, unfortunately.

Aren't these engines renown for their reliability? I'm hoping it isn't the head gasket...any recommendations for testing prior to shipping her off my local Indy?
 
BMW engines are renowned for their troublesome pcv.
The only thing you can really do is let the car warm up thoroughly and then go for a spirited drive.
That might unclog the pcv, but it might be broken already. If a lot of engine sludge mixed with water vapour collects in the pcv and freezes it can do damage.
I dont know if you need your car tomorrow, but the best thing to do is put it in the sun tomorrow (if there is any) and let it idle for a long time (about 1 hour), and then take it for a spirited drive, and see if the smoke goes away.
What you can do is put a hairdryer (high heat, high air volume) on the pcv and its connected hoses to get it extra hot during idling.
The pcv (the oil seperator) is a black jar and looks like this:
$_58.jpg

Its probably located at the back of the engine somewhere under the inlet manifold (passenger side)

you can also let the engine idle for about 10 min with the oil cap off once the engine is warm. That might also force the pcv to unclog some passages

If that all doesnt help the pcv has to be replaced.
 
Ok, novice here. Audi A3 (money pit) had the same traits as mentioned - head gasket and ouch! BMW 325ti had the same traits as mentioned, exchange the coils - all sorted and this was on 140k+ miles!
 
Hmmm, knackered ccv certainly can lead to excess oil consumption but your group of symptoms all together sound a bit more serious to me.

Ok, first things first. I assume you have the silver metal cam cover version of the N52? This has a separate ccv which sits underneath the intake manifold. Few things to test:

1) What happens if you remove the oil cap with the engine running? You should feel light vacuum pressure if you cover it with your hand.

2) Remove the top DISA valve (the one that’s easy to get to) and see if there is a lot of oil in the intake manifold. Answer =yes then almost certainly a knackered ccv. Answer = no is probably worse news as maybe something more expensive like head gasket.
 
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