what fuel additive to use

[robnye]

I have a common problem in my Vauxhall Zafira, which is that the engine cuts out when decelerating, ie when moving of highway onto slip road or slowing down for roundabouts, then the engine wont restart for a couple of minutes.

i have taken it to garage, but no codes have shown up when run through the diagnostic tests, no lights are showing on the instrument panel either.

someone tried cleaning something out for me... which lasted about 2 weeks,

someone has suggested trying a fuel additive into the petrol tank, but they couldnt remember what to suggest. i know there is hype about using supermarket petrol (90% of the time we buy from supermarket), but when we have bought from non supermarket petrol, we still have the same issue

as anyone done this?
what was it you added?

[Markyt]

I had similar symptoms (different car though) when there was an air leak in the fuel system - a pump seal had gone, in my case, and it only did it when the engine was cold and under load, so testing at garages didn't show anything up.

[robnye]

originally i thought it was due to weather, but it happens anytime of the year/day/weather... there just doesnt seem to be any consistency to when it happens - some trips, it doesnt happen, others several times within a short period of time (depending on road/roundabouts/sliproads etc)

[sherrymatthews]

It seems it is quite common problem with Zafira. One of my friend had same problem. he tried all the ways.. later part exchanged it for a VW... suggest to try vauxhall forum:confused:

[robnye]

ive looked there - most have changed egr valve or idle control valve, but still have the problem...... also seems to be a common problem with the type of engine in other recently modern cars

just thought i might try the additive to cut out the possibility of it being the fuel

[TiTheRev]

The trouble with supermarket fuels is that is doesnt have the extra additives that help clean the engine and give you the extra MPG etc. There's a good chance you've coke'd up the throttle body or injectors which would have been cleaned by 'normal' garage fuels. The additive may be able to clean this out, but it will only happen again if you continue to use the cheaper fuels. It's been recommended by Auto manufacturers and watchdogs etc, to use one tank normal and one tank supermarket fuel if you want to make a saving without messing up your car.

[robnye]

thats what i thought, any suggestions on what additive to use?

[TiTheRev]

Redex, STP, Wynns, Wurth...most will do a similar job, but make sure you get the petrol/diesel version as applicable ;)

[hewhoisnotintheknow]

asda sell redex for £3something a bottle, i shuv it through every 5000 miles which is once a month :( !

[robnye]

asda sell redex for £3something a bottle, i shuv it through every 5000 miles which is once a month :( !

do you buy your petrol from asda as well?

do you do this because of an issue you had, or cos it was recommended?

[hewhoisnotintheknow]

do you buy your petrol from asda as well?

do you do this because of an issue you had, or cos it was recommended?

I buy all my diesel at one shell station, NEVER asda

I just shove it through as i rely on my peugeot so much and its never let me down!

[TiTheRev]

Better to be proactive rather than reactive :D

[bryanb]

thats what i thought, any suggestions on what additive to use?

Millers, it's expensive but it gives me an extra 3 mpg. in a non turbo diesel, and keeps things clean. It has been tested and it raises the cetane value by 4 points.

[Conor]

Non of these snake oils will stop the fault from occurring.

[robnye]

Non of these snake oils will stop the fault from occurring.

how do you know?
admittedly im not sure whether to use one of these or try the non supermarket fuel first

[TiTheRev]

Technically it may not even be the issue, but it certainly will help changing fuels...

[photome]

A colleague of mine had the same problem in his company Zafira. The lease company have now given up with it and took it off him to sell/scrap with 65000 on the clock on an 06 plate

[bryanb]

Non of these snake oils will stop the fault from occurring.

Not suggesting they will cure fault. Just answering OP's question "Which additive to use?"

[Pew Pew Pew Lasers!]

You'll be wasting your money with fuel additives, and I doubt the fuel is the source of the problem.

Look elsewhere. Since it only happens when you're decelerating - ie not using any fuel - it could be a number of issues.

[nickcc]

If you buy fuel from one of the three major oil companys you don't need additives as they are injected into the product during loading at the distribution terminal. As stated previously, Supermarket fuel does not normally contain additives, thats why it used to be cheaper.

[shown73]

This is such an old chestnut, that has been chewed over many times. Last time, on these forums, a couple of tanker drivers came on to say that they delivered the same fuel to various outlets, supermarkets and normal retail outlets. The reason it's cheaper in supermarkets is the same reason that they have any other special offer, simply to attract customers. I have a full bottle of Redex in the garage that I was going to use in an old banger, but got rid of it instead. I'm reluctant to put it into my newish Mondeo, because my instinct is that it would do more harm than good. Modern ECU's are clever little gadgets, and can adjust themselves to whatever fuel is being used, as far as I know, at least up to a point. Why deliberately upset something that is working well? I've always run my Mondeos, petrol that is, on the cheapest grade of unleaded, as per the handbook, and the engines have always been as sweet as a nut, even with well over 100,000 miles, just regular oil changes etc.

[lincroft1710]

Check in your owner's handbook first - fuel additives are not recommended for some cars.

[Mi_bargains]

I would recommend you try this

http://www.netparts.co.uk/store/index.php?main_page=product_info&products_id=7

If there is anything causing a blockage it will clean it out.

[Tally-Ho]

If you buy fuel from one of the three major oil companys you don't need additives as they are injected into the product during loading at the distribution terminal. As stated previously, Supermarket fuel does not normally contain additives, thats why it used to be cheaper.

Hi,

I presume by 'the three major oil company's' you mean Shell, BP and Esso?.

Now discounting Supermarkets (Tesco,Asda, Morrisons etc) do other oil companies such as Texaco, Total, Jet, Gulf or even the smaller ones such as Murco, Star, Rix, Imperial, Phillips etc etc put additives in their petrol/diesel?.

I haven't noticed any difference at all between any fuels but just am interested to know.

Thanks

Tally

[northstar23]

I normally put a bit of Redex through once every 6 months or so.

Wilkinson are doing 100% extra free at the moment. £3.89 a bottle which is a decent price.

[onejontwo]

This was a common Vauxhall fault , and basically required removal, cleaning and refitting of the throttle body , checking the breather pipes for blockages and setting up the idle speed with their on board diagnostic equipment. I suggest you take it to a Vauxhall dealership as they will be used to this problem, either that or clean the throttle body out yourself and see how it goes.
Good luck!

[nickcc]

Hi,

I presume by 'the three major oil company's' you mean Shell, BP and Esso?.

Now discounting Supermarkets (Tesco,Asda, Morrisons etc) do other oil companies such as Texaco, Total, Jet, Gulf or even the smaller ones such as Murco, Star, Rix, Imperial, Phillips etc etc put additives in their petrol/diesel?.

I haven't noticed any difference at all between any fuels but just am interested to know.

Thanks

Tally
Different Oil companys use different additives. At Shell Stanlow distribution terminal there are many different Oil companys collecting the same basic Shell product but only a few of these companys take additives. Oil companys do not sell their own additives to any other Oil company or third party. It is also unlikely that Tanker drivers would know what additives were injected into the load that they are carrying as the loading system is, and has been for many years, automated.