morrisons derv

[shaggy]

ive been filling up at morrisons at knottingley for a couple of months now and i noticed a bit of diesel knock on start up
it goes away after 5 mins or so
took it to my diesel man and he says the derv is to blame
so ive had 2 tanks of esso & a tank of bp through it and its gone!

why is this?
i thought all diesel was the same and up to a standard

[Woodzie]

ive been filling up at morrisons at knottingley for a couple of months now and i noticed a bit of diesel knock on start up
it goes away after 5 mins or so
took it to my diesel man and he says the derv is to blame
so ive had 2 tanks of esso & a tank of bp through it and its gone!

why is this?
i thought all diesel was the same and up to a standard

Don't use it myself , both the surf and the focus tdci hate the stuff , and they use it quicker=less mpg

[BUSHWHACKER]

ive been filling up at morrisons at knottingley for a couple of months now and i noticed a bit of diesel knock on start up
it goes away after 5 mins or so
took it to my diesel man and he says the derv is to blame
so ive had 2 tanks of esso & a tank of bp through it and its gone!

why is this?
i thought all diesel was the same and up to a standard

Cheap supermarket diesel (city diesel) is for modern diesel engines and contains less lubricating properties than brand name diesel. I always (used to anyway) filled up at the lorry pumps in garages.

[shaggy]

yeah i hadn't noticed that before it is city diesel
doh stands to reason
also i DONT get the knock when on oil
dont understand why though

may just dissconect both battery's and see if the "reset" helps

[davemaxx]

really interesting thread because i've only been using morrisons fuel since iv'e had the truck and its my first diesel and i thought it was knocking a bit on initial start up unless i had put a redex treatment in the tank, i was thinking perhaps it was just cold or addicted to redex, and planning on mixing a couple of ltrs of veg-oil in there, 'i'll have to try a named brand and look for a difference'.

so i suppose that means cheap fuel is cheap fuel then.

[nero279]

interesting, I topped up at a Jet garage for the last tank, was using either BP or Shell, but as money's been tight started using the supermarket stuff a couple of months back, was OK to start with, but...

recently i've been having major poor economy: dropped to around 10mpg for a couple of tanks, thought it was leaking. Anyway economy seems to have gone back up, but it seems very noisy.

[BUSHWHACKER]

interesting, I topped up at a Jet garage for the last tank, was using either BP or Shell, but as money's been tight started using the supermarket stuff a couple of months back, was OK to start with, but...

recently i've been having major poor economy: dropped to around 10mpg for a couple of tanks, thought it was leaking. Anyway economy seems to have gone back up, but it seems very noisy.

It's the low sulphur content in ULSD (city diesel) that causes the noises in older diesel engines.

[plumb bob]

And apparently the lack of lubricating agents MAY be partially responsible for causing the IP seals th start leaking

Edit;

Also, if you check out the US sites, they have very poor quality derv, that produces low power, and is very high in sulphur and all the other nasty stuff we've taken out in this country.

[shaggy]

well
i seem to have improved mpg and more power
or is it just the placebo effect??
the knock has now gone so wont be using supermarket derv again anyway

[Linda]

I use morrisons and sainsburys quiet often as a mix 50/50 with veg and I've had no probs at all - I wonder if this is because of the veg???

[Bibs]

I always used Tesco an no veg - up until the other day - engine had started knockin lately. Read this post - filled up from Shell and touch wood - not had any knockin the last couple of days. Fingers crossed.

[shaggy]

well i drive at 80/85 where possible and normally get around the 20 mark
unless im doing a test then i drive at 70

but ive driven it like a $$$$ this week because ive been late etc and now got 24mpg using esso and bp

[gwh200]

I use morrisons and sainsburys quiet often as a mix 50/50 with veg and I've had no probs at all - I wonder if this is because of the veg???

if the derv is poor quality and requires extra lubricity,adding veg is exactly the right step.cos the veg is thicker (and cos wikipedia says that the molar mass of veg oil is greater than derv)the extra lubrication in the form of unrefined volatiles in the veg aid the lubrication and/or stop the "knock"

[davemaxx]

after blocking the egr valve and giving the engin a proper flushing and new oil and filter about 6 months ago, i was pleased to see how relativly clean it was and how slowly it was discolouring when checking its level once a week.

on monday morning i gave the fuel tank a 25% rapeseed oil, treatment.
the engin runs smoother and crisper and seems more responsive.

the drawbacks
it stinks, and although it was due for an oil change anyway, i can say that the engin oil has changed from dirty black, to something that resembles marmite in 48 hours.

anyone els found the same.