Fierce smoke from diesel normal?

[DaveVoorhis]

I test drove a 2002 E39 530d today. It had been parked for about a month, and behaved normally around the city streets for a mile or two until I reached the motorway. I matted the throttle to get a feel for the acceleration. It accelerated acceptably, but blew a thick cloud of blue-grey smoke -- and I mean *really* thick; it was enough to obscure the motorway, other cars were backing off and turning on their lights. I released the throttle and the smoke stopped. For about five miles, it smoked slightly each time I accelerated, after which it cleared up and no longer smoked, even with full-throttle acceleration.

Is this normal for a diesel that has sat for a bit?

[pingu]

Given that you drove a mile or two to the motorway, I can't see what difference the sitting for a month could have made. I'd better 'fess up to not having a diesel but given that you almost never see large plumes of smoke from diesels (at least not so large that people back off and turn on their lights), I wonder if that diesel was a bit sick.

[Ferret]

Diesels do tend to smoke quite a lot after they've been granny-driven for a while then someone's given the gas pedal a good slam...

If the vehicle's been owned by an older person for a while before you've gone in and booted it, I'd expect motorway obscuring smoke for the first couple of times you floored it as it blasts particulates out of the exhaust.

However, be warned!

The later 530d's had particulate filters so should catch most of this crap, and 530d's are extremely prone to throwing their turbo bearings at around the 70k mark. These turbos were the first generation of ball bearing turbos instead of floating the turbo shaft on an oil bath. When these are on their way out it'll blow blue/white smoke out of the back in thick clouds - if it's been stood for a while it could be a sign that the turbo seals are starting to leak and it's ready to go.

They're also highly prone to throwing injectors, high pressure pumps under the passenger seat and various other bits...

These are first generation high pressure common rail diesel engines - a lot tends to go wrong with them after 70-90k miles, but if you can keep them going they're an awesome engine! Incredibly powerful, awesome sounding and good economy wise :)

If you decide that you want one of the modern bimmer diesel engines, beware the swirl flaps.

Google for bmw swirl flaps and lawsuit, see what happens :)

Basically there's a bunch of very small very thin metal plates just in the ends of the intake manifold to cause airflow to roll and mix with the diesel for better emissions during combustion.

Unfortunately after a few years metal fatigue gets the better of them, one of them breaks off and the engine grenades... so if you do grab one of these cars look up the proceedure for removing the swirl flaps before you have to shell out for a new engine.

Good hunting!

[Tiger]

I'd recommends having BMW dealer look over the car for you if you are considering it. If owner won't let you do it, walk way.

[DaveVoorhis]

... and the engine grenades...

Oh, good. :( If it isn't a VANOS-gobbling M5, it's a turbo-munching, swirl-vane lunching 530d. Maybe I start looking for a 540i/6, or buy that manual tranny 850i in Exeter?

The last E39 M5 I looked at went something like this:

Owner: <starts engine>

Engine: voom!KlaklakKlaklakaKlaklakKlaklakaKlakaklaKlak... !

Me: VANOS is shot...

Owner: Yeah.

Me: So that should knock a few thousand off the price, eh?

Owner: Bwaaaaaaahahahahahaha!

Me: <cue sound of walking away>

[Ferret]

Oh, good. :( If it isn't a VANOS-gobbling M5, it's a turbo-munching, swirl-vane lunching 530d. Maybe I start looking for a 540i/6, or buy that manual tranny 850i in Exeter?


If you're after a 540i/6, mine may be coming back on the market in the new year relatively cheap... there's a family owned E39 540i/6 (As well as a 2.8 Z3 being sold by a friend, though I'd rather have the e39) on the horizon around march time that I'm seriously considering :D

[Zeuk in Oz]

I have the same engine in my X5 and that amount of smoke is, I would think, probably not normal. Mine does not smoke at all under any circumstances.

I seem to remember someone talking about blockages somewhere causing that but can't remember where. Take the car to either a dealer or BMW expert for assessment before you consider buying it.

The 530d is a great car, by the way.

[DaveVoorhis]

If you're after a 540i/6, mine may be coming back on the market in the new year relatively cheap... there's a family owned E39 540i/6 (As well as a 2.8 Z3 being sold by a friend, though I'd rather have the e39) on the horizon around march time that I'm seriously considering :D
Let me know when you go to sell your 540i/6.

In other news, today I bought a cheap '97 E39 535i (the V8 one) to knock around in while I look at smoky diesels and rattly M5's. I'll pick it up either tomorrow or Saturday. It's a 5spd, with M-tech wheel, shift knob, & suspension; full OBC, sport seats, unmarked genuine Alpina 18" wheels, and some other goodies.

[Ferret]

I have the same engine in my X5 and that amount of smoke is, I would think, probably not normal. Mine does not smoke at all under any circumstances.

I seem to remember someone talking about blockages somewhere causing that but can't remember where. Take the car to either a dealer or BMW expert for assessment before you consider buying it.

The 530d is a great car, by the way.

Blocked breather, memory jogged!

Yeah these cars blow oil smoke badly, as the 3.0d has a craply designed breather on the earlier models... they changed the design of the replacements you get from the dealer now so it doesnt happen again.

[pcross]

It could be normal for a diesel that sat for somewhat longer than a month. Two things can come into play: 1) if the vehicle has sat unstarted for quite a while, the valve seals may dry out allowing oil to pass into the cylinders (Mercedes diesels are notorious for this). If they have not become brittle, they will re-hydrate (re-oildrate?) and the smoke will go away. 2) A stuck PVC valve will almost always result in the engine generating white smoke although not too much. PCV valves usually become unstuck quite readily upon sustained driving.