Disco 300tdi - clouds of smoke out the back : (

Took off the oil cap. Seemed no different from normal.
Cant see any action around the gasket, but there's plenty of places i could miss it.

Tried to wobble the turbo vane assembly from side to side. Feels solid. Tiny, almost click, or movement, but no real play / runout.

Uploading another vid. Ive listened to the recording, and it sounds pretty rattley, but its never sounded like a sports car, and i reckon the video makes it sound worse than it is.

https://www.youtube.com/watch?v=PPSiQTMmh3A

julianf said:

Took off the oil cap. Seemed no different from normal.
Cant see any action around the gasket, but there's plenty of places i could miss it.

Tried to wobble the turbo vane assembly from side to side. Feels solid. Tiny, almost click, or movement, but no real play / runout.

Uploading another vid. Ive listened to the recording, and it sounds pretty rattley, but its never sounded like a sports car, and i reckon the video makes it sound worse than it is.

https://www.youtube.com/watch?v=PPSiQTMmh3A

Click to expand...

turbo runs on an oil film, so there will always be a teeny bit of movement

Do you reckon one of these would work on the 300tdi head -

OVERHEAD VALVE SPRING COMPRESSOR by BERGEN valve stem seal replacement tool | eBay

...too late. Ive just bought one (needed to do it quick if there was any chance of it getting here by tomorrow)

From all accounts, theyre pretty poor, bend, and need welding up, but, with luck, itll do for 8 valves.

Of course, i dont know if it is the valve stems, but theyre the cheapest option, so ill give them a go, and hope for the best.

check your turbo hose's have not de-laminated inside, this would cause a intermittent restriction on air flow and result in a lot of smoke.

Ive had them all apart apart from the bottom hose on the intercooler, and that one is mostly metal.

On second thoughts, ive had the turbo end of that one off too, just not the intercooler end.

I should check that, just to be sure.

White smoke is coolant being burnt

Blue smoke is oil being burnt

it looks predominantly white suggesting the engines using water?

it also looks a teeny bit blue however could be video quality

smell your coolant, does it smell like exhaust gases?

if so you HG could be on the way out

Yep - i thought that also, but other people were sure the smoke was blue, and my partner thought it smelt the other night too (i did not notice, but thats not unusual)

And...


Ive just taken the car for a drive. The length was enough to get it up to temp in about 1/5 of the trip.

Not a lot of smoke (nothing even close to the other night) but there were puffs here and there. Not able to tie it down to a specific action / rev range, but probably more when under load and in turbo range - but, again, inconclusive (not every time)

When i pulled up at home, the exhaust was clear. I got my partner to rev the engine, and it stayed clear, however...

Ive not put mineral diesel in the car in my ownership. 100% methyesters - which smell different on the exhaust.

But now it smells of burning mineral oil, even without the smoke.


I took off the cap on the headder, like you suggested - no smell there.



As a side note -

The valve compressor turned up this morning, but the stem seals did not.
I have a scrap head here, which ive tested the compressor on, and it seems to work ok, but id be surprised if i make it through the task without some blood blisters...

Can someone check this please -

Im planning on doing the stem seals tomorrow (assuming they turn up), without removing the head.

So as i dont loose the valves, i need to be very certain of the positions of the pistons.

My plan is as follows -


Rotate crank till timing pin goes in IP.
Check flywheel groove is visible.

(this is where i get mixed up - crank turns 2x for every 1x of the IP - so if the ip pin is in place, the flywheel groove should always be visible?)

Put into gear to lock engine.

At this point, piston #1 (closest to front of the car?) is at TDC.

Remove rocker assembly.

Do stem seals on inlet and exhaust on cylinder one.



Then it gets troublesome for me....


I figure on printing out a pie chart type thing, divided into four, and sticking it to the crank dampener.
If i then take out of gear, and rotate the crank by 1/4 of the rotation, i should be at TDC on cylinder #3, right? So that's one in from the back of the car?

Timing order being 1342.

Back into gear, and do the seals on #3s valves.
Our of gear, another 1/4 turn, and same on #4 (rear of engine)
Same and then #2

Rocker assembly back on.

No oil leak.


Im sure the above is almost right, so, if you can pay special attention to any errors, i would be most grateful!

Mate I think you'll find that when the TDC mark on the crank pulley is lined up with the timing case mark then cylinders number 1 and 4 will be on TDC, for the purposes of your exercise you will not need to do anything with the timing pin into the Injection pump sprocket, you will need the rocker gear shaft and rocker arms out of the way, you can do both cylinder 1 & 4 valve stem seals in that position.
The engine will,(should), be hard to turn over with none of the valves opening , (against compression), but it is possible with a good socket and bar and a bit of muscle, without the rocker gear in play none of the valves and pistons can clash.
When you have successfully removed and replaced the valve springs and collets (2 inlet 2 exhaust) of 1 & 4 in situ, (good luck with that, bloody hard enough to do on the bench, but good luck all the same!), you can then rotate the crank 180 degrees, (half a rev), clockwise and do likewise to cylinders 2 and 3.
The firing order of any engine is only the relation of the camshaft and fuel injection point to the crank, crank rotates 360 deg, cam rotates 180, ie half the rpm or the engine.
For safety, plug up all the holes inside the rocker/valve areas where you could drop collets and small bits and pieces with little bits of rag.
I really don't think you are on the right path with your diagnosis from what I've read so far, my money is on the turbo seal on the exhaust side, I have an old '97 clunker Tdi with well over 300K on it and I seriously doubt it even has any stem seals left, and it does not blow blue smoke like yours showed in the vids. But hey it's worth a try to do the seals. Like I said before, hope it goes well.

You may well be right, but i just thought that the stem seals should be easy and cheap enough...

Ive got a scrap head here that ive 'practised' on with the spring compressor, and im semi-confident that itll be possible.


However -

Ive just done aprox 45 mins driving, with a short break at half way. For the whole trip, i stayed under 2krpm, but there were hills etc. so the engine was loaded, but just not under turbo.

No smoke the whole way.

The oil will still flow through the turbo, and i suspect it still turns a bit, but you would imagine that it would leak more when spinning quick?


I can see no reason why the rings, if damaged, wouldnt have been leaking on this trip?

valve stems usually just make it blue on startup as the oil seeps past at night.

did you say you usually run it on bio not derv?

why not drive up a hill over 2k with the turbo on and look for smoke?

you didn't overfill or anything and manage to get oil in the exhaust did you?

Ive never put a drop of derv in it, in the 3 yrs or so we've owned it.

Not been overfilled - and, besides, i had not topped it up for a while.

The hill test you suggest is sensible - its just always a concern doing that type of thing, too far away from home, with only one car... (trying to get the 101 back on the road at present)

I purchased a head and turbo this morning that ill pick up tonight or tomorrow, so it may be easier to swap the turbo (not that ive looked up how much work that is) and go from there?

julianf said:

Ive never put a drop of derv in it, in the 3 yrs or so we've owned it.

Not been overfilled - and, besides, i had not topped it up for a while.

The hill test you suggest is sensible - its just always a concern doing that type of thing, too far away from home, with only one car... (trying to get the 101 back on the road at present)

I purchased a head and turbo this morning that ill pick up tonight or tomorrow, so it may be easier to swap the turbo (not that ive looked up how much work that is) and go from there?

Click to expand...

i'd stick some derv in to see if you have dodgy bio batch. could be as simple as this.

check oil for thinning or stickiness and smell it.

also if you didn't check oil level. then you need to top it, run for a bit and check the level again.

I fear diesel would kill it stone dead. It or me, one or the other...

Joking apart, i take the fuel from a much larger tank, and ive used about 3 of 400ltrs from the tank since it was last topped up, without issue. So its not like its a fresh fill up.

I check the oil levels reasonably frequently. I probably last checked them a week or two before, but we have done a lot of driving in the past fortnight (wedding in north wales, back to devon, visits in essex, back to devon). I checked the oil before the wales trip for sure, but i cant recall if i did before the essex trip. The drop in levels that i mentioned may well be mostly due to the drips that ive been meaning to deal with.

Ill have another check for feel of it. Are you hinting at ring gumming, and leakage round the bore? Ive read (but never had the misfortune) of levels rising with bad spray patterns and ring gumming. My only experience of levels rising was when the lift pump started leaking, but that was at least one oil change back.

We live away from anywhere, and, if the car is started up, it will run for no less than 25 mins. So no short trips. The bio is always full conversion, so similar viscosity to dino. Ive never run veg in it.

Id imagine that a ring issue would have come on more gradually? And also that it would smoke all the time. Ive done another hours driving this morning, and no smoke at all - but i did not go above 2k again.

Im off on a 2hr round trip this evening to pick up a new (used) head and turbo - i figured id drive gently on the way there, and then give it some on the way back (once i knew i had the parts) and see what happens, as, theres no point in changing the turbo until im fairly sure.


One more bio thing -

Incomplete combustion with bio smells a lot more bonfire / bbq. We used to run our central heating boiler here off it, and ive also smelt it with cars before.

Mineral oil smells a lot more 'chemical plant' and its that smell that im getting from the disco. Its very different for me, as, like i say, ive never put diesel in it, so the chance is pretty noticeable.



Anyhow, i dont know what it is... which means it could be fuel related, but id be surprised. Im open to suggestions from anywhere though!

I guess ill know more after tonight.

Hi is it anything like this

https://www.youtube.com/watch?v=nXPrjmWRi1Q

That was mine last year, I replaced the head gasket and lift pump etc and it made no difference. Tended to happen more on a hot start. It was running on bio for 30k miles at the time.

Turned out the timing belt I fitted the year before had settled/stretched just enough to cause this. Had it all timed up properly and it was cured.

I think it was about as bad as that when we came off the motorway. It still didnt smell like bio though.

Timing belt was last done a few months back. You can check the crank and IP timing without removing the case, but there's no way to check the cam without removing the crank dampener, right?

My belt was replaced with help by a pal of mine a 6 months or so before the problem started.

The guy who sorted it for me thinks we got the timing slightly out as you cant lock the auto box with a pin when doing the belt, but it was close enough to start and run ok until it settled down which then caused my problems.

It drove me mad and turned out to be something so simple. It could well be worth stripping the crank pulley and front cover off and double checking its all lined up as you also replaced the belt recently.

Mine as you saw smoked like crazy but it did not stink of fuel which was 100% bio.

Your thinking on the rings not being gummed up is correct, that does not happen over a short period of time, by any stretch, and unless the crankcase breather system is chock full of oil and sludge the compression is still ok.
A diesel needs good compression to fire up cold, if yours buttons away straight up then the rings, valves, injectors and pump are all working fine.
Your vid with the engine running with the rocker box filler cap off shows no excessive blow-by, that eliminates ring leakage.
If you've ever seen a video of a runaway diesel engine, (plenty on youtube) i.e. combustion of it's own sump oil, you see the amount of smoke and noise that creates, definitely not your problem.
A really small amount of oil leaking past the turbo seal will create a fair amount of smoke without giving the "runaway" effect.
The timing issue also mentioned, I don't think that's it either, last time I changed the belt on our Tdi, I found the last mechanic had the cam set 1 tooth retarded and the injection pump set half a tooth advanced and apart from knocking the power on acceleration down a bit and making it run a little hotter in our tropical heat it had no other effects, certainly not excessively smokey.

Did about 3hrs of motorway / A road driving yesterday. No smoke at all.


My current hypothesis assumes the following -

a) that the video i uploaded was just cold start smoke
b) that i was mistaken as to the smell when taking the video


Im thinking now that the smoke that i experienced at the start of this thread was oil burning up external to the engine.

The block, on that side (the turbo side) of the engine is pretty 'wet', and, when i pulled up on that evening, there was more oil than usual dripping out the bottom of the car.
Also there was some spatter (not much though) on the rear of the car.

(ive had things like the lift pump leaking before, where the whole rear window gets covered, but it wasnt as significant as that)


To be sure -

Ive done nothing to the motor, and its not smoking now.


My plan now is to pressure wash all the oil off that side of the engine, and try and work out where its coming from. It really does not seem to be comming from the rocker cover, and, i think, the only other oil pipes on that side are the turbo feed and return.


I hate it when you read a thread on a forum and the OP never bothers to update it when they (i assume) find a fix, but this ones not exactly fixed yet.