Hi all,

I took my car (E39 530d, 155,000 miles, new turbo at 106,000) to National yesterday to have the oil changed after 9000 miles on the old oil (also National) and no issues. The car seemed fine driving home. I took it on a four hour round trip today, and on the motorway I noticed a slight hissing noise under full throttle. There may also have been a slight power loss, although this could have been in my head. Once I was off the motorway and onto slower roads, I noticed that the car produces quite a lot of black smoke under heavy acceleration, which it didn’t before. With the bonnet up, I can hear the hiss when idling, and I don’t think it was there before.

So my questions to the good people of STW are:

Is this normal/will it go away with time/am I damaging it further if I continue to drive it?
Is it likely to be National’s fault and if so can I do anything about it?
Will I die?

I was planning to drive to Scotland tomorrow (around four hours!) so any advice would be much appreciated!

I’d say that they have loosened an intercooler or boost pipe by your description

Excellent, cheers dirtyboy. I’ll be able to have a better look under the bonnet tomorrow morning when it’s all cooled down. Any other ideas?

Thanks!

Yep boost pipe loose or holed would be my first guess

I would say its over filled and pressurising. If all you have done is change the oil then check that first.

Too much oil is my guess
Edit: too late

Boost pipe split or loose clamp

That doesn’t sound like overfilled oil at all. If it was it would be blue smoke.

Black smoke is an air leak somewhere. Car thinks it’s getting more air than normal so pumping in more fuel which isn’t getting mixed properly so comes out the back as thick black smoke.

Same symptoms as my Mondeo had when air pipe to intercooler was holed / split.

Over about 200 miles it got rapidly worse with power loss and smoking exactly as you describe (hissing noise too).

Wasnt expensive but the decline in performance became borderline undrivable over that short time so worth a look ASAP. Mine may have been atypical in terms of speed of failure I guess.

As others have said. Over filled with oil. Check also the oil cap has been fitted correctly or that the dipstick is pushed into the tube properly.

+1 for split or loose turbo pipe.

It’s not overfilled with oil. Even if it was it wouldn’t produce black smoke.

Oil burning is blue smoke.

Boost leak or split air pipe is black smoke.

Blue Smoke – blue smoke results from burning engine oil. This is a mechanical problem because engine oil isn’t supposed to be getting into areas where it can be burned. There could be a faulty injector pump or lift pump, which would allow oil to mix with fuel and be burned. The valves or valve stem seals could be bad. Worn cylinders and piston rings (X-tra Lube can help with this problem) allows oil to seep where it shouldn’t. Or you could have a problem as simple as having put too much oil in the engine.

It’s black smoke, not blue, black.

Hissing is a boost leak.

My bets on inter cooler pipe dislodged/split……I’d start with all the pipes near the filter and anywhere else some buffoon has shoved his giant forearm/tools 😆

Crikey a simple oil change that can lead to black smoke? 😯

Bloody dodgy mechanic you got there.

Are these the engines with no dipstick?
Maybe the spanner monkey has been shoving his sump sucky pipe down every orifice to see if he gets a result?

Should be possible to isolate source of hissing sound, there are some small hoses on induction system. Work through the air inlet system from filter box, turbo stuff and through throttle body and into inlet manifold (big black plastic 6 legged thing on pavement side of engine block).

Guess the filter housing is mounted at front of engine at one end of inlet manifold, as others have said check the pipes there and you should find source easy enough, access might be tight so try a small mirror if needed to see underside of some parts.

Pretty careless by National.

Another reason why I do my own maintenance, pretty hard to mess things up when essentially there should be only 2 things to be removed, sump plug and oil filter.

Does sound like a split or loose pipe though.

I’d go with split in a turbo related pipe somewhere – happened to mine (due to old age) – possible with this car too.

I struggled to track mine down as the split/sound was only obvious when putting load on the engine and revving on the driveway wasn’t enough.

am I right in thinking these are a VNT turbo with vacuum activation?

If so then it could be a split/disconnected vacuum actuator pipe, the slight hissing could be the vacuum leak and the smoke due to the VNT not activating so you don’t have enough ‘boost’.

The most obvious and first to look for is one of the turbo-intercooler, intercooler-inlet manifold pipes. Check the inside radius of corners and look for chafing on other pipes and brackets. There is often oil residue seeping out of any splits as there will generally be a bit of oil in the turbo pipes, especially likely if you have already had one replaced.

Obviously check any pipe fittings too as it could just be a loose clip.

Update!

Just been out on the driveway with the car. Checked the oil level, it’s very slightly over full but nothing that would concern me. After taking some of the decorative engine bay covers off I noticed that an intercooler pipe was just about slipping off one of its connections – I’d have never spotted it without the advice on here, so thanks STW! Popped it back on (no easy feat) and tightened up the Jubilee clip as best I could (needed a screwdriver with a shorter handle really, it’s pretty tight in there) and took her for a spin – good as new 😀

I’ve no idea how National could have set this off – the pipe in question is on the other side of the engine bay to the oil filter (although it is low down so I guess it could have been while they were draining the oil), but I’m glad this seems to be cleared up. I’ll keep an eye on it over the coming weeks to make sure it doesn’t slip off again.

Cheers everyone!

From the description I’d say the intercooler pipe is just a slipping off one of its connections. In fact I’d put money on it. You may need a short handle screwdriver to tighten the jubilee clip.

I’ve no idea how National could have set this off

Could be a coincidence, ofc. Might’ve been loose for ages and just happened to slip sufficiently now to cause your symptoms.

If its blue smoke its oil.. black sounds like a loose intercooler pipe.
You might need some stubby screwdrivers to tighten a loose clip if theres not much room in the engine bay..

National like to build in problems while they have your car at their mercy.

All mine had was a tracking check and still managed to lose a CV clip on the journey home. What a coincidence.

I wouldn’t be at all surprised if they slit a hose while messing; you take it back coz it’s not right and they claim coincidence and charge the repair.

Since when did Jubilee clips ever work themselves loose?
Co-incidence, my arse!

:sticks hand in air:

The replacement I put on came loose about 5 hours from home (and I thought I had tighter than gnats chuff).

Same as handlebar grips….wipe the metal pipework and inside of inter cooler pipe with rag to remove oil residue, spray with hairspray attach pipe and do up inter cooler hose clip………works on the blanking caps on diesel leak off pipes too!

blue smoke, you say? That’ll be screenwash. Nasty business.

Since when did Jubilee clips ever work themselves loose?

Jubilee clips are rubbish, you want proper hose clips. They are notorious for slipping so yes, it could well be a coincidence (especially since it then slipped again after refitting).

Mikalor clamps are what you want.

Since when did Jubilee clips ever work themselves loose?
Jubilee clips are rubbish, you want proper hose clips. They are notorious for slipping so yes, it could well be a coincidence (especially since it then slipped again after refitting).

Presumably it has whatever clips the manufacturer fitted all those years ago and that have never given any problems…
…until now.

nah, if he has had a new turbo then odds are the original factory clips are gone and replaced with jubilee clips.

Remove the hose and clean the bore and the fitting with solvent (IPA, brake cleaner etc) and refit. A decent (not silverline or some other guff) jubilee clip should be fine.