406oc.co.uk

Got huge problems here, the passat (1.9tdi) went up it tonight.
First indications of a problem was a slight noise under the bonnet about a minute before I dropped off a customer. As he got out, we both noticed excessive smoke coming from the exhaust whilst at idle. I had been sat for 5 minutes whilst waiting for him with no smoke coming from the car, and I would have noticed a smell. We had travelled a distance of about 8 miles before I dropped him off. I nursed the car back to base, loads of smoke upon operating the throttle, so coasted mainly with a dipped clutch. The owner came out to take a look, I had checked the oil on monday and it had oil in it - although there has been an issue with a leak from the sump, it had been repaired, and only a small amount was leaking (the car had been parked up for two days and only a 10p sized amount was showing on the gravel last night). There was no oil warning light illuminated on the dash at any time, nor water light. The car has been hunting recently, with the occasional puff of white smoke out of the exhaust with the hunting, which we attributed to a faulty connection on injector two, and only seemed to be a problem at idle). Car has smelt smoky since I started driving it, which I put down to a knackered cat.
Base op started it up, it was smoking heavily from the exhaust, enough when operating the throttle to make it impossible to see behind the car.
All of a sudden, the throttle stuck open, the owner could not get the throttle off, even turning the engine off and pulling the key out did not stop the engine from revving flat out!!!
Eventually it came off, and we noticed oil leaking from the exhaust. Lots of it.
Owner has since took it for spin up the road and it did the same again, throttle sticking open and smoke everywhere.
Engine sounds ok, there is a throaty noise but it seems to be coming from somewhere around the exhaust manifold/cat.
Any ideas guys?
Car still has power, there is no oil in the water/water in oil etc.

Owner has started it up again, it got half a mile before suddenly over-revving, purging the engine of oil thru the exhaust and finally cutting out (oil warning light came on). He has since been back to it and it will turn over now but won't start.

I know the possibles, valve stem seals, piston rings, turbo bearings and blown head gasket.
I don't think it's the head, as there are no visible signs of water in the oil/vice versa
I would think if the rings/valve stem seals went, there would have been obvious power loss??? Until the owner got in it, there was no physical sign of anything wrong, apart from the smoke. Apparently there is an oil leak all the way down the road to where it is now sitting, with a HUGE amount all over the floor

Are we going to take bets on what's blown lol
(I think my money's on stem seals and tubby bearings).

Sounds like classic turbo seals, followed by the car running flat out on it's own sump oil

Seconded on turbo seals. Very common on Renault dCi's

Surely there'd be oil all in the MAF if that was the case?
I couldn't see properly and didn't have tools but the MAF is bolted onto the airbox on these, so I unclipped the airbox and ran my fingers inside the MAF and it was clean?

Getting confuzed here, I think the Pug goes puddle sucker-filter-MAF-turbo-intercooler-inlet. Does the Passat have the filter after the turbo?

No, same as, I just thought there'd be *some* oil on t'other side of the turbo as well?

The MAF only 'sees' clean incoming air, the turbo feeds directly to the inlet manifold.

The turbo seals would explain the car running by itself. When you say is was smoking at idle was it blue/white smoke or diesel black smoke?

Sometimes a Diesel can build up a 'pool' of oil and occasionally pick it up and eat it and return to normal later, this is a sign that oil is building in the pressurised side of the turbo outlet piping. It would pay you to whip the I/C off and drain it (possibly run a bit of petrol/solvent cleaner through it to swill it out).

Welly wrote:The MAF only 'sees' clean incoming air, the turbo feeds directly to the inlet manifold.

The turbo seals would explain the car running by itself. When you say is was smoking at idle was it blue/white smoke or diesel black smoke?

Sometimes a Diesel can build up a 'pool' of oil and occasionally pick it up and eat it and return to normal later, this is a sign that oil is building in the pressurised side of the turbo outlet piping. It would pay you to whip the I/C off and drain it (possibly run a bit of petrol/solvent cleaner through it to swill it out).

It's always been white smoke, never black.
Hmm... the car has been hunting intermittently since I started driving it, the "hunt" was always accompanied by a "poof" of white smoke out of the exhaust every 2-3 seconds and the car would shake from side to side like a dog. This, the owner insisted, was down to injector no 2 having a faulty connection, he said it had happened before and been tested.
I'm wondering now if this was the entree before last nights main course and dessert.
The 407 when it spat the turbo out the other month had oil EVERYWHERE, including on the intake side - I just assumed the passat would be the same lol, plus, there's a pipe running from the rocker cover down to the turbo, this pipe and the air intake join there in a V about two inches from the turbo itself.
After running at least once for nearly 5 minutes at maximum revs until it ran out of oil on an engine that's done more than 453k, I will be bloody lucky if it hasn't eaten most perishable items
Another unusual feature it's had recently was the odd moment when asking it to *work* and it feeling very retarded all of a sudden, and the exhaust noise became "throatier", which after knocking the engine off for a bit would clear itself and the power would return to normal.(which was pretty much how it sounded when the owner booted it to clear the smoke and it ate the engine oil).
The car now turns over but won't start. Cross your fingers for me guys although I thought I'd prep for worst case scenario (engine £375 inc. delivery on standby)

On a hot diesel engine, if the injector hickup'd and sloshed in too much fuel I'd expect a 'poof' of black smoke not white (maybe it'd be bluey/white when cold *think: lorry cold-starting*).

I would say a poof of white would be hot oil combusting. Normally a whiff of oil being burnt in an engine will show up blue but if you increase the amount of oil it goes to thick white plumes which hang around for ages.

I would have a look in the intercooler and piping and you may well see a fair bit of oil. The turbo is probably still working ok but getting worn at the seals (you can't blaim it really for the mileage).

Turbo's probably pretty much fooked lol, I remember borrowing it in February when I flushed the pug keys down the crapper and thinking I had a copper following me with sirens blaring, only to find it was the turbo whistling

Just thinking about the exhaust and cat- will it be ok after a couple of litres of oil chugging through it??

supafrisk wrote:Just thinking about the exhaust and cat- will it be ok after a couple of litres of oil chugging through it??

Not much you can do about it really but it should just burn off.

Thinking about what you said earlier - the reason you saw oil in the air inlet of the 407 may have been due to the recirculating dump valve pushing oil back through!

supafrisk wrote:Just thinking about the exhaust and cat- will it be ok after a couple of litres of oil chugging through it??

a mate of mine has a vetra v6 and the HG went chucking oil through the exhaust. he changed the engine and kept the exhaust. it smoked for a while but a good blast cleared it up with no ill effects. the oil in the ex system just needs to burn out.

I've got a 1.9 TDI and if the turbo seals were to go on it, I wouldn't expect any oil to make it up to the MAF...

Now for the barely-educated speculation: I think if it's refusing to start, it could have blown its head gasket due to the over-revving (which I believe will probably have been well over the rev limiter)? Or perhaps the injector nozzles have been clogged by the burned oil?