Club 80-90 Forums

I'm not an expert in Diesels at all and need some advice.

Brother-in-laws T25 1.6TDI (1990) has just started to smoke very badly from the exhaust, but there's no evidence of any major oil leaks and there's no loss of water and no build-up in the water pressure.

The tail-pipe is very very dirty (jet black deposits) and it smells of burning. He says it happened suddenly with a loss of power and the maximum speed was 50mph.

Any clues as to the cause?
Could a blown turbo cause clouds of smoke?
Pistons ring?
Other possibilities?

The smoke coming from the exhaust looks idenitcal to this...

http://www.youtube.com/watch?v=OI-DbQX1Kh4

Any clues as to the cause?

Could a blown turbo cause clouds of smoke?
Yes, especially when cold, pulling away or hill climbing. They more usually slowly degrade rather than sudddenly, with a thin trail of blue under load worsening to clouds of blue stench as the months go by.

Piston ring(s)?
Possibly, don't know how common on these, certainly the 1.9TDs can take enormous abuse without breaking rings.

Other possibilities?
Cracked head or blown head gasket...
'Running on' breather mist oil or welled up oil in inlet (overfilled or breathing heavily (age!))

Black smoke or blue?

Has it ever 'run on' on oil? (Accelerated without any throttle, with clouds of smoke?
Was it topped up with oil that recently, or even on that day?

Is the turbo 'dripping oil' (clamber underneath, take a rag)

Is this all the time, exactly when is the smoke pouring out.. ?

HarryMann wrote:Black smoke or blue?

Definitely not black, more like a light grey.

Has it ever 'run on' on oil? (Accelerated without any throttle, with clouds of smoke?

Sorry, I don't understand the question. The engine runs and ticks over OK, but whilst ticking over the smoke is coming from the exhaust.

Was it topped up with oil that recently, or even on that day?

No.

Is the turbo 'dripping oil' (clamber underneath, take a rag)

Unfortunately, the engine tray on these are large and cover most of the engine underneath. We did look for traces of oil but couldn't find any - although at the moment, the tray might be collecting it and it might be a while before the tray fills so that it drips onto the ground.

Is this all the time, exactly when is the smoke pouring out.. ?

It's all the time. On tick-over there is smoke coming from the exhaust.When the accelerator is pressed the smoke get far worse and pours from the tail pipe.

Anyone know where we can get an exchange Turbo or new unit at reasonable cost? The closer to Berkshire the better!

Thanks.

I'd say your bottom pulley has slipped.

SplendiferousII wrote:I'd say your bottom pulley has slipped.

As far as I know there is only one bottom pulley (the crank shaft pulley) and it is neigh impossible for that to slip, so I'm a bit confused with that one.

If the bottom pulley has slipped as you suggest (or more likely the belt has slipped on the bottom pulley), the engine would mis-fire - which is isn't. Unless you mean a different pulley.

How would that produce the smoke from the exhaust??

Unfortunately, the engine tray on these are large and cover most of the engine underneath. We did look for traces of oil but couldn't find any - although at the moment, the tray might be collecting it and it might be a while before the tray fills so that it drips onto the ground.

Jack it up, axle-stand it and take the n/s wheel off, the turbo is then easy to see

Sorry, I don't understand that...

Diesels can run on oil as well as diesel fuel (which is also a refined oil).. if oil is getting into the inlet tract anywhere, in sufficient qunatity, the engine 'might' 'run-on' - that is accelerate without any throttle being applied, usually very noisy, with lots of grey/balck smoke and noise - and potentially dangerous!

However, it now sounds like your problem is not that

Because your inlet and exhaust are probably now heavily contaminated with oil, it will be difficult to be sure of a diagnosis in the short-term should you disconnect the turbo somehow (or its oil supply)...

Two things come to mind to progress this diagnosis:

1) Remove the breather pipe from the cam-cover or breather separator, start the engine and see if the engine is breathing heavily (blowing oil mist and fumes out when revved)

2a) Disconnect inlet downpipe (from air-filter unit) from the turbo from compressor inlet, and see if that tube is dripping oil;

If clean or not too bad then...

2b) disconnect the turbo outlet hose from the compressor outlet or inlet manifold (can be a bit of a struggle, its a short hose usually with an ally concertina stretchy tube over it as a heat shield) and see if that shows signs of 'lots' of oil in it

The exhaust will have oil in it anyway, regardless of the source if it's smoking badly..

To explain myself a little clearer.

I did look at the video posted and without reading the headline (Blown Turbo) reasoned that the smoke shown was white rather than Oil Burning Blue.

White smoke would indicate to me unburnt fuel and hence the pup timing had gone out of time.

This happened to my neighbors 1.9TDI and another friends on his 1.9TDI engine. And resulted in lose of power, loads and loads of white smoke on both occasions.

The cause on both of these was Slipped bottom pulley.

The use of the term TDI is fuzzy here as both of these vans where early T4's with mechanical fuel pumps. So maybe AAZ's?

You also called yours reading back a 1.6TDI. so I now assume this is a 1.6TD? If so the bottom pulley should (may) not be an issue.

So a question - is the smoke blue or white?

Yes good question... BLUE or WHITE

No too difficult to check the state opf the bottom pulley, timing belt etc..

The choke control on 1.6TDs also affects the pump timing I believe, advances it slightly... take a good look around or take to a time-served diesel technician

HarryMann wrote:Yes good question... BLUE or WHITE

No too difficult to check the state opf the bottom pulley, timing belt etc..

The choke control on 1.6TDs also affects the pump timing I believe, advances it slightly... take a good look around or take to a time-served diesel technician

To answer both the above questions, to me it appear to be more white than blue.

SplendiferousII, Yes, I confused you with the TDI reference, Sorry. It's a 1990 1.6TD Westfalia (Type 2). The red one on the right of this photo:

[img:640:480]http://s136500617.websitehome.co.uk/her ... T0006b.JPG[/img]

We will be dropping the engine pans tomorrow so will be able to provide an update then.

Just removed the Turbo unit from the van.

It's heavily contaminated with oil all around and the turbo blades on both sides have a awful lot of play. Both set of shafts for the blades can be moved about 3-4mm side to side with ease (both are quite floppy).

Is this normal? I would have thought they would be on some sort of bearing and with no detectable play at all?

There should be no play at all. Tis knackered by the sounds of it.

There should be no play at all.

Not really, although with oil bushes in a new one its often hard to tell. There's always some play in them (these are plain floating bushes), up to around 1mm rock being quite normal if you get a finger on both ends of the shaft. The shaft actually orbits at low speeds as well as rotating.

However, this one sounds well kanckered as you said

Refurbs go for £200 ~ 400, don't expect a seriously good life out of a cheap refurb from an unknown company. New from £500~800

If on limited funds, try looking at 1.9 VW TD diesels in scrapyards, Seat Toledo diesels have them as well, often Garret T2s that fit with the rectangular port and 4 holes.n The std JX fit is a KKK K14
They usually all have an ID plate riveted to them or a good quality sticker.

You'll need a good quality (unworn) bi-hex(12-point) 12mm socket, either 3/8 or 1/2 sq drive + a powerbar to get the special bolts out. Its possible to come down from above on them if you remove the airfilter cannister. Don't loose them they're £13 each! If they break, well, that happens, so clean the protruding thread first and try some Plus Gas or Rust Buster, but just make sure that socket is well onto the clean head. When they loosen they just go crack, so watch your knuckles aren't directly in the firing line

Get the exisiting turbo off and check the exhaust manifold face for flatness and cracks - there are often other things that need sorting at the same time, no good bolting a good turbo back onto a bad manifold, it'll overheat something soon enough.. small cracks are acceptable, but the face needs to be surfaced somehow if its seriously burnt away, ditto exhaust manifold/cyl. head. You will also like as not need a new set of exh manifold studs, nuts and those thick washers (importnat) if you take that off. Note that 3 sets of its holes are extra large to allow 'float' about one port.

Checkout the Wiki on all this stuff too - if you haven't