200tdi Disco: 'Smokey Joe'

[ThreeSheds]

My Disco has a smoking habit.

It only runs on two cylinders when starting (with mucho smoke) and when hot it produces big puffs of smoke when on light (almost trailing) throttle.

The smoke is unburnt diesel (not black smoke, it's blue-grey and stinks like paraffin)

When hot the car runs well and gets up to 80 on the flat.

It fires easily (on two) but after starting it takes a lot of coaxing to get it above tickover, but once I manage to get it rev'd up the other two pots come on song and and after that it will tickover on all four.

The car shows 127000 miles (but no provenance on that)

The problem is getting worse in that six months ago it was fine - now I daren't take it to work because it smokes out the underground carpark

I don't really know a lot about diesels, but I had a little play with it and have the following thoughts/observations:

1. The turbo spindle does have some play, but not much. I don't know how much is too much but I would guess it at about ten thou.

2. There was a big split in the pipe into the turbo, but obviously this wouldn't affect anything much (short term at least). The other hoses look ok to me and 'pump-up' well when the engine is rev'd.

3. The intercooler doesn't look too gungy inside.

4. It doesn't 'breathe' when I lift the oil filler cap, so I assume the rings are ok.

5. The tappets all have decent clearances.

6. All glow plugs have the correct resistance and are getting 10 volts when on.

7. When starting from cold it's the central two pots that fire ok and the outers are missing badly. This is repeatable (ie always the same pots).

8. It doesn't use oil or water and each of those fluids show no signs of contamination from the other.

All of the above appears to indicate to me that the turbo side of things is ok and the compression is ok and the the fuel burns ok when the engine is hot.

The only thing I can think of is that the two injectors are 'weak' and so are not producing an effective spray. If they are spurting rather than spraying it would mean that when cold there would be very little fuel burnt, but when hot it might still manage to ignite it.

Maybe?

perhaps?

I think...?

Are there any pitfalls when changing injectors?

There are four 2nd hand injectors on eBay at £60 buy-it-now, is that a reasonable price?

Any suggestions/comments please?

Roger

[discojmz]

Im currently looking at the possibility of needing new injectors and/or rings. my problem isnt as bad as yours, and I shall update later after trying the next batch of concentrated injector cleaner (fill up replacement fuel filter with it and swap them over) later today.

personally, I wouldnt buy 2nd hand injectors. there is nothing to say that they are any better than the ones you already have. I think my local guy quoted roughly 2x that for full reconditioned ones. he tests them for free also, so I might have to whip mine out and take them to him at some point

[Skanny]

4 injectors for £60

I sell mine out at only £8 a piece + pnp

I have a known good set here you can have at an LR4x4 members price of £30 delivered if you want to give it a go?

[Guest DiscoTD4]

4 injectors for £60

I sell mine out at only £8 a piece + pnp

I have a known good set here you can have at an LR4x4 members price of £30 delivered if you want to give it a go?

That sounds like a great deal, I'd replace all of them for that price, then at least you know you can eliminate them.

Out of interest how did you establish which cylinders are playing up ?

Good luck

[Guest DiscoTD4]

Another thought: how did you test the glow plugs - if you put the meter on them whilst all in situ and wired up, you will be testing the collective voltage of all 4 as they are wired in parallel ?

Best to un-wire them and measure the resistance individually of each one as a quick check and then remove and test them on the bench if suspect.

Forgive me if I'm teaching you to suck eggs

[ThreeSheds]

I have a known good set here you can have at an LR4x4 members price of £30 delivered if you want to give it a go?

I think I'll have those then please! How would you like payment?

Out of interest how did you establish which cylinders are playing up ?

I felt the exhaust pipes to see which got hot quickest. Within a few seconds the inner two were too hot to touch but the outers were only slightly warm.

Best to un-wire them and measure the resistance individually of each one as a quick check ...

That's exactly what I did a couple of weeks ago and the outer two had failed and have now been replaced, but made no difference to the problem I checked them again this week and each of the four reads 0.8 ohms.

Sadly this thing is really p1551ng me off right now and making me reluctant to use it - if I could just get it fixed I know I would love it again

Roger

[Phantom]

I think I'll have those then please! How would you like payment?

I felt the exhaust pipes to see which got hot quickest. Within a few seconds the inner two were too hot to touch but the outers were only slightly warm.

That's exactly what I did a couple of weeks ago and the outer two had failed and have now been replaced, but made no difference to the problem I checked them again this week and each of the four reads 0.8 ohms.

Sadly this thing is really p1551ng me off right now and making me reluctant to use it - if I could just get it fixed I know I would love it again

Roger

Are you sure its not an air issue, with air in the fuel you'll have very poor starting and lots of smoke..................

Lee

[ThreeSheds]

Are you sure its not an air issue, with air in the fuel you'll have very poor starting and lots of smoke..................

Lee

Thanks for the thought, but I would have expected that the fuel is ok since it does 80 on the flat? Not too hot on diesels though...

[JimAttrill]

Your split in the pipe to the turbo means that you were running on unfiltered air. Not that that matters too much in the UK with your rather damp climate but from the symptoms you describe I would reckon you have bore wear resulting in low compressions and therefore bad starting, white diesel smoke etc. The engine will still start well when hot, and go quite well. I would get a compression test done. You may be able to get away with honing the bores and changing the rings as I did after my disastrous experience with the KanNot™ filter.

[ThreeSheds]

Your split in the pipe to the turbo means that you were running on unfiltered air. Not that that matters too much in the UK with your rather damp climate but from the symptoms you describe I would reckon you have bore wear resulting in low compressions and therefore bad starting, white diesel smoke etc. The engine will still start well when hot, and go quite well. I would get a compression test done. You may be able to get away with honing the bores and changing the rings as I did after my disastrous experience with the KanNot™ filter.

Good point! Thanks for that - but a major stipdown is not something that I relish since I all ready have the RRC in pieces which takes all my cash and time and I don't want two sheds on the drive... Also it's may daily driver with only the CBR600 for backup. I think that since well sorted 200tdi engines seem to be worth a bit, I may wait until the RRC is on the road and then tackle it - instead of just flogging it on as I was planning to. I couldn't sell it like it is anyway.

For the moment a potential 'quick fix' is a more attractive option - so I will try a different set of injectors first. Beyond that is possibly a pump (I may be able to borrow one to try) and then off with it's head

Rog