Does petrol in a diesel affect the emisions test?

[bull996]

I have just read the diesel fuel thread, regarding it freezing etc.

I have a 1998 Renault Master van, which i think is a pretty crude diesel engine, that currently wont start! I need to get it MOTd next Wednesday, so I have a problem. I am assuming its the fuel that has waxed-its fuel that has been in the tank since September and it is only 1/4 full. The van hasnt moved since then and its -12 outside.

If I was to chuck a bit of petrol in ( I reckon its old enough to handle a bit of petrol), would this affect the emisions test?

[HD Adam]

I wouldn't put petrol in it.

I have used Jet Fuel (Kerosene) before in diesel in very cold conditions.

[Jakg]

Diesels don't get an emissions test for the MOT - only a visible smoke test.

[MJK 24]

Jakg said:

Diesels don't get an emissions test for the MOT - only a visible smoke test.

Nonsense.

[tr7v8]

If it has already waxed then putting petrol in it won't do any good. Modern diesel is apparently good for -15 Deg C so should be OK. Personally I'd get a can of Easy Start & try that, or alternatively get a gas lighter & run some of that into the inlet. But you'll need a good battery & possibly a jump source as well. My father used to run a fleet of old diesel vans & some times on cold days they took a huge amount of persuading to start! Good pocket money earner for me as a 14 year old though!

[GilbertGutbucket]

Jakg said:

Diesels don't get an emissions test for the MOT - only a visible smoke test.

[parapaul]

GilbertGutbucket said:

Jakg said:

Diesels don't get an emissions test for the MOT - only a visible smoke test.

The joke may be on you - I can't find a link to a tester's manual, but I'm sure that's right. Emissions test for petrol engines, smoke test for diesels. That's the reason a lot of 'tuned' diesel cars can run quite happily without any form of catalytic converter.

[MK INDY]

Diesels are tested for smoke density only at mot, but with a smoke meter, not just a visual check.

[Eggman]

Depends on the age of the vehicle whether the meter is used or not. Older ones only get a visual check.

I reckon the OP should be fine adding a couple of litres of petrol. A small amount won't knacker the injector pump and I can see no reason why it should smoke any worse.

(If it is a bit smokey, pop a bottle of 'Comma Diesel Magic' in the tank. It's the most effective diesel injector cleaner I've found - my Defender occasionally resembles a cross-channel ferry at startup, and a dose of that stuff improves matters no end)

[Laurel Green]

I'd also check for water in the fuel filter - well, ice actually.

[aw51 121565]

If the Van last ran in September, the Diesel in its tank will be "summer grade" and therefore "waxed" or solidified.

Not much to suggest except heating all the pipes - or set up a jury-rigged seperate tank feeding the injection pump with fresh ("winter grade") fuel. You just have to heat the injector pump and feed pipes in this latter case before trying to start the engine - and I bet it starts first try after heating the system up !

The "extra tank" trick will also feed "winter grade" fuel into the tank (some is returned to the tank during running) which should then ease your problem as the weather warms and allow use of the vehicle's main fuel tank again...

[TheLurker]

parapaul said:

GilbertGutbucket said:

Jakg said:

Diesels don't get an emissions test for the MOT - only a visible smoke test.

The joke may be on you - I can't find a link to a tester's manual, but I'm sure that's right. Emissions test for petrol engines, smoke test for diesels. That's the reason a lot of 'tuned' diesel cars can run quite happily without any form of catalytic converter.

Tis true. I find that millers diesel sport (or is it eco max now?) is good for reducing somke.

[Parrot of Doom]

I doubt it will be diesel, it isn't cold enough. I'd be looking at faulty glow plugs, or even frozen coolant.

Spray a load of easy-start down the intake, see what happens.

Edited by Parrot of Doom on Sunday 26th December 10:42

[sparks_E39]

It's a bad idea to put any petrol into a diesel engine.... a small amount could bugger the engine.

[Eggman]

Not so.

It used to be fairly standard practice to run a 10% mix in winter, and I have heard of people running much stronger mixtures than that. I wouldn't put it in a common rail engine (or for that matter a PD, without researching it first), but older engines will be fine.

[bull996]

Tip top advice guys. I charged the battery overnight, bunged a set of jumpo leads on as well, tried to heat things up a bit with one of those jet heater type things used is large spaces, and after much turning and heating of glow plugs she started!!!

Too her for a long drive and all is well-except I cant get any hot air out of the heater.....bloody cold in there I can tell you!

Dont suppose anyone knows how to bleed the cooling system on one of these? I am sure it was working the last time.

Thanks everyone.

[Eggman]

If it's still very cold where you are, chances are there's nothing wrong with the cooling system - diesels just don't make much heat, hence a lot of the newer 'posh' diesels come with auxiliary (fuel burning or electric) heaters. See if a radiator muff improves matters.

[bull996]

Eggman said:

If it's still very cold where you are, chances are there's nothing wrong with the cooling system - diesels just don't make much heat, hence a lot of the newer 'posh' diesels come with auxiliary (fuel burning or electric) heaters. See if a radiator muff improves matters.

Yes its still minus 6 here, so it could be that. No rush for the heater TBH, now I can get it too the MOT I am happy.

Thanks