300tdi Stalling and Smoke

Hello good people,

My 300tdi 90 was determined not to start this morning (it was -12°C according to next door's Golf) but eventually fired into life with the usual small puff of smoke.

Having set off however I soon (50 yds) noticed the revs dropping regardless of how hard I mashed my frozen foot down, blue smoke (although it was so cold it was 'steaming' too) and then it stalled. I restarted it, which it did without problem, and set off again (I was blocking the road at this point). Got twice as far and it did the same. I restarted again and it ran fine — while running there was no smoke, no undue noise and no initial lack of power.

Over the next 5 miles the same loss of power then stall with blue smoke occurred twice more (always as I started to slow for a junction), but upon restarting she was fine. Once the engine was up to temp it ran fine for the next 20 miles to work.

Normally I would have turned back but today I was picking up two others (inc. one director) who were stuck in the snow, I felt duty bound to demonstrate that a Defender was the right choice of commuter vehicle

Any ideas on here what the problem could be? It's a '95 M, with 150k on the clock and I am the second owner so it's been well serviced.
Many thanks,

Jim

The white smoke you are seeing should not be steam unless you have a coolant leak into the cylinders, it will most likely be vaporised diesel as the engine will compress it but not ignite much of it when the engine is very cold.

The blue smoke is oil - I am not sure why it when it stalled the blue oil came about, unless it is something to do with with air and it's turbo oil.

For one reason or another the engine is struggling particularly at low speed and when the engine is slowing down towards idle speed, when the engine is running above idle with the throttle pressed it keeps throwing in the fuel, if you let go of the throttle it stops the fuel entierly until the speed gets too low and it bumps in more fuel to keep the engine at idle. It sounds like the governor that controls this is failing for one reason or another, it may very well be cold related - water in the fuel causing it to ice up!?!

I would replace the fuel filter for starters.

I also wanted to say it sounds like it might be air/turbo related, a blockage but the fact it then ran fine for 20 miles makes me think it was directly related to the engine being so cold.

Waxy doosel p'raps? Is minus 12 cold enough fer that?

DomEllis said:

Waxy doosel p'raps? Is minus 12 cold enough fer that?

Click to expand...

yep, but only if there's "summer grade" fuel in the tank

Cheers for that chaps, I think it might have been down to either waxy diesel or some water contamination (although that doesn't really explain the blue smoke).

I just took her out to the shops for lunch (along with half the office) and she started and ran fine, nothing untoward — in fact once going she loves the nice cold air.

I'll keep an eye on it for now, BBC says -9°C tonight...

DomEllis said:

Waxy doosel p'raps? Is minus 12 cold enough fer that?

Click to expand...

Fair point, however, UK diesel sold in the winter (especially this far into the cold snap) should be rated to a minimum of -15, this is the CFPP (cold filter plugging point). Fuel companies will have allowed for the cold snap and probably dropped it even lower at the moment (or else every cold diesel out there would be failing now).

The diesel isn't old by any chance is it, bought in the summer or something? You don't have any veggie or engine oil in there do you?

I would probably throw 4 or 5 litres of petrol into a full tank of diesel during this cold weather, helps cold starting.

It shouldn't be old, I bought it from a BP up the road at the weekend.

I did see two HGVs, a quarry truck, a Mitsubishi pickup and a Rover 200 at the side of the road between Northwich and Church Minshull so I didn't feel like such a pillock having to pull over every two minutes!

Re: petrol on top of diesel —*any negative effects from this?

JimWood said:

Re: petrol on top of diesel —*any negative effects from this?

Click to expand...

I'd heard that that could knacker your fuel pump

discomania said:

The white smoke you are seeing should not be steam unless you have a coolant leak into the cylinders, it will most likely be vaporised diesel as the engine will compress it but not ignite much of it when the engine is very cold.

The blue smoke is oil - I am not sure why it when it stalled the blue oil came about, unless it is something to do with with air and it's turbo oil.

For one reason or another the engine is struggling particularly at low speed and when the engine is slowing down towards idle speed, when the engine is running above idle with the throttle pressed it keeps throwing in the fuel, if you let go of the throttle it stops the fuel entierly until the speed gets too low and it bumps in more fuel to keep the engine at idle. It sounds like the governor that controls this is failing for one reason or another, it may very well be cold related - water in the fuel causing it to ice up!?!

I would replace the fuel filter for starters.

I also wanted to say it sounds like it might be air/turbo related, a blockage but the fact it then ran fine for 20 miles makes me think it was directly related to the engine being so cold.

Click to expand...

I agree with you and the blue smoke is probably black smoke, overfuelling and something as you say to do with the fuel pump freezing up, probably be fine after a good run. The white smoke too much fuel when engine cold and cant burn it and then hot it chucks out the black stuff.

But as you say any water in the system will freeze and checking the filters is a good idea.

DomEllis said:

I'd heard that that could knacker your fuel pump

Click to expand...

Not seen waxed fuel for years now I wouldnt put anything in the tank, just make sure there is no water in the filters, and there always is, always a good practice to do a filter change leading into winter.

When it was -20 a few years ago never got one of our vehicles with waxed fuel just water in fuel and air systems

Got a 5 gallon of veg oil in my garage and it froze up, wudent even pour out, so fook knows what its like in some of them tanks even if it is mixed.

DomEllis said:

I'd heard that that could knacker your fuel pump

Click to expand...

Not at that blend, petrol offers NO lubrication to the pump so on it's own it would not last too long.

Petrol with lots a oil mixed up nicely, thats a different story.

I gallon to a full tank of diesel will cause no harm, the diesel is slightly more viscous in the cold so reducing it a bit with petrol is good for the pump, because too viscous and it cannot lubricate the moving parts with fine clearances (and we are talking fine, i.e. on assmebly of a pump if you don't wet it with a little fine oil or diesel the parts won't go together).

I totally agree with what Discomania is saying, talk to any long time served HGV driver and they'll tell you the same, it was once common practice to put a few litres of petrol into the diesel tank to stop the fuel waxing, I've done it myself in the wifes Rangerover DSE as well as my Defender.

dazzx10r said:

I totally agree with what Discomania is saying, talk to any long time served HGV driver and they'll tell you the same, it was once common practice to put a few litres of petrol into the diesel tank to stop the fuel waxing, I've done it myself in the wifes Rangerover DSE as well as my Defender.

Click to expand...

He is right we used to do it all the time, but I still dont think it is necessary these days and I recal from years ago that we had the coating coming off the insides of the tank because of petrol, the coating was to stop the tank rusting and it shriveled up, peeled off and blocked them up.

However I cant remember if it was somebody who put petrol in instead of derv or they mixed it.

Worth looking into that before you try it.

Mine did the very same thing today, struggled to go, left it idling and the temp came up but no heaters, had to rev the foker up and then it worked and then it wouldnt rev above 2k, then it cleared and I got to the bottom the road and it chucked it again, but now its ok. Daughter abandoned it she thought it was on fire at one point, and refused to go on the motorway with me to her work, so I fooked off and got some shopping myself. But there are a few cars abandoned along the roads today. Even my screenwash is froze in the garage brrrrr. My filters are all new aswel

Good point is the cold has froze my leaky wheel rims hehe