Technical Fiat 500 1.2 Pop Spark Plugs

[loveshandbags]

We're probably stepping outside the 'envelope' of this thread but IMHO it's still relevant. The servicing schedule for the 500 was possibly devised for 'normal' fuel before the corrosive effects of ethanol were accounted for. Using better plugs and changing them before the 18K is what should now be recommended to offset the poorer economy of the blended fuel. Not too mention more frequent oil changes.

I incorrectly referred to bio-fuel on a previous posting in relation to cars designed to run on E85 - it should have been Flexi-fuel. When it was been produced here as a byproduct of cheese manufacturing it was cheap but it had to be to offset the reduction in fuel economy (wiki E85). I didn't use it since I didn't have a car suitable to use it at the time - but it was available today minus the excise duty I would use it given the environmental benefits. On a turbo charged engine you can make the most of it (Click here). I would live with the fact that the engine has a shorter life.

Pure ethanol has an octane rating of 113 but that does not mean E5/E10 fuels are higher octane - the oil companies just blend other lower octane feedstocks to compensate - so 'tuning' the engine in this way will have no effect . The end product you buy does not have a higher octane rating.

Fuel companies are laughing all the way to the bank because adding ethanol is a cheap way to get the octane rating they need & they can blend less expensive feedstocks.

That is annoying.
The only company in Ireland that provides petrol with 98-99 octane is Maxol (Click here) and I get that when I can. It's priced the same as the standard fuel which is only 95 octane. The 155TB which is a T-jet only gives it 162bhp on 98 octane. There are other models which benefit from an increase in octane but they are primarily turbo charged engines.

 

[jrkitching]

We're probably stepping outside the 'envelope' of this thread but IMHO it's still relevant.

Actually highly relevant since my recent experiments suggest the life of the standard ZKR7A-10's may be significantly compromised by the use of E5/E10 petrol. As you quite rightly say the 169A4000 engine may never have been developed or properly tested to run on fuels containing alcohol. Interestingly the number of posts complaining of rough running &/or poor starting seem to have increased since E5 became widespread in the UK & with the impending introduction of E10 things can only get worse. If these problems can be addressed simply by fitting an alternative iridium plug then the benefit to the 500 community could be considerable & I will keep posting my findings once I've got them installed.

If anyone from the technical side of FIAT should be reading this, working with NGK to produce a suitable projected tip iridium plug could help us all - but sadly I suspect development of the FIRE engine has now largely stopped and those folks are concentrating their efforts on more modern designs.

 

[jrkitching]

Interestingly the number of posts complaining of rough running &/or poor starting seem to have increased since E5 became widespread in the UK & with the impending introduction of E10 things can only get worse. If these problems can be addressed simply by fitting an alternative iridium plug then the benefit to the 500 community could be considerable & I will keep posting my findings once I've got them installed.

I fitted the DCPR7EIX's yesterday & the car had its first decent run on the new plugs today. The slight lumpiness I noticed recently has disappeared & as yet it hasn't done its occasional smoky start trick. I can't say I've noticed any great difference in low speed performance but the car will pull cleanly in all gears from the ecodrive recommended change points (note that's before the arrows illuminate). Too early to say what the impact on economy will be, though today's numbers (64.6mpg indicated over a 50 mile round trip) were within the limits I've come to expect from the car. I can confirm that it starts & runs without any issues.

It'd be nice if someone else out there is either brave or foolish enough to join me in my experiment (I'm looking at you Maxi ); it'd be good to have someone test these plugs at the other end of the performance spectrum in the 1.2 engine.

Interestingly close examination of the wear patterns on the old plugs shows that the spark occasionally jumps sideways towards the base of the side electrode & it seems in practice the firing pattern of the projected tip plugs is more randomly distributed than its designers intended. From what I've seen, I don't think the standard fit plugs will continue to work reliably for 18000 miles & this could explain many of the reports of rough running & poor starting we've seen on the forum.

 

[306maxi]

I've got some 900 mile old ngk's in at the moment so it's a no from me for now but next tine I might try some iridiums

 

[frupi]

I fitted the DCPR7EIX's yesterday.....
It'd be nice if someone else out there is either brave or foolish enough to join me in my experiment (I'm looking at you Maxi ); it'd be good to have someone test these plugs at the other end of the performance spectrum in the 1.2 engine.

As a matter of interest, how much did you pay for a set of these plugs? Cheapest I've seen is £25.56 for a set. Our own plugs are on 5000 odd miles, still on original plugs. Wondering if it is worth me joining your experiment?

 

[jrkitching]

As a matter of interest, how much did you pay for a set of these plugs? Cheapest I've seen is £25.56 for a set. Our own plugs are on 5000 odd miles, still on original plugs. Wondering if it is worth me joining your experiment?

That's exactly what I paid for mine .

Thanks for your interest in my little experiment. At 5000 miles, your plugs should still have some useful life left & unless you've a reason to suspect they might be past their best, I'd leave them for another 5k or so. Also, you might want to wait until I've put a few thousand miles on my set, when I'll be better placed to say whether or not they give any real benefit over the standard ones.

 

[frupi]

That's exactly what I paid for mine .

Thanks for your interest in my little experiment. At 5000 miles, your plugs should still have some useful life left & unless you've a reason to suspect they might be past their best, I'd leave them for another 5k or so. Also, you might want to wait until I've put a few thousand miles on my set, when I'll be better placed to say whether or not they give any real benefit over the standard ones.

Yup, no probs and thanks for the advice. Our little POP never gets ragged, rarely hits 70mph and is certainly not running lumpy or anything else untoward. I'll leave things alone for a while, in fact, when the car gets its second service next year, I'll change the plugs myself and let the garage know it's a job they don't have to worry about. They can just do the oil/filter and brake fluid change.

 

[loveshandbags]

.. you might want to wait until I've put a few thousand miles on my set, when I'll be better placed to say whether or not they give any real benefit over the standard ones.

Unsure of the benefits are re-instating the 1.0mm gap on the Iridiums is worth doing (or even risking it) but it would be nice if some 'poor' soul would consider getting a set of the Denso tough Iridiums to see if I missed out when I had the 1.4. The Denso standard iridiums didn't make difference to the fuel economy with the 0.8mm gap but it did feel more responsive.

 

[loveshandbags]

Yup, no probs and thanks for the advice. Our little POP never gets ragged, rarely hits 70mph and is certainly not running lumpy or anything else untoward. I'll leave things alone for a while, in fact, when the car gets its second service next year, I'll change the plugs myself and let the garage know it's a job they don't have to worry about. They can just do the oil/filter and brake fluid change.

I did that when I put the 500 Sport in for a service but unfortunately I had to buy a set of standard NGKs for the 'records' - it 'saved' me one hour's labour. The NGK Iridiums were 'off the books'.

That said in the US the 2012 500 MA was supposed to have NGK Iridiums fitted as standard but it didn't materialise. It seems that they're not as diligent as us Europeans in servicing their cars - I've nothing to back that up so I could be talking through my rear end. I wonder if it was because they were using a higher content of ethanol at the petrol stations - some using 85% - but then they stepped the usage back because of the 'outcry'.

 

[jrkitching]

Unsure of the benefits are re-instating the 1.0mm gap on the Iridiums is worth doing (or even risking it) but it would be nice if some 'poor' soul would consider getting a set of the Denso tough Iridiums to see if I missed out when I had the 1.4. The Denso standard iridiums didn't make difference to the fuel economy with the 0.8mm gap but it did feel more responsive.

TBH on the 1.2 I'm more concerned about losing the projected tip than the gap - the Ir plugs seem to make more of a difference in the Panda (apart from the gap the spec is correct for that engine). Speculating now but at low rpm gapping to 1.0mm could be counterproductive as that is when the voltage needed to fire the plugs is at its highest and the reduced gap could give more reliable ignition (hence the absence of that low speed lumpiness & dubious starts). Certainly I've got another couple of hundred useable rpm at the bottom of the rev range in the Panda; I haven't really driven the 500 enough to tell yet.

At the top of the rev range, you're more likely to benefit from the slightly quicker burn by gapping to 1.0, but that's for someone else to test.

The next half dozen fuelly figures will be interesting, particularly as the 500 has been doing rather well prior to fitting the new plugs (61.5mpg averaged over the last 10 tankfuls).

If I can match or slightly better the economy & get rid of the occasional hesitant running on initial startup, I'll be happy - and if they last the claimed 60k that will be a real plus. But it's still very early days yet.

 

[loveshandbags]

TBH on the 1.2 I'm more concerned about losing the projected tip than the gap...

What is the difference in lenght on the projected tip compared to standard ?
How risky is it to remove the washer on the plug or replace with a much thinner one that wouldn't deteriorate.

 

[frupi]

I did that when I put the 500 Sport in for a service but unfortunately I had to buy a set of standard NGKs for the 'records' - it 'saved' me one hour's labour. The NGK Iridiums were 'off the books'.

To be fair when the car goes in for second service, I guestimate it will have barely covered 11000 miles and I believe the plugs are a mileage related change not a time related change? Therefore me changing to Iridium plugs well before 18k, shouldn't cause any issues especially on a low mileage service plan which is what we'll have. I could of course be wrong though!.....

 

[loveshandbags]

To be fair when the car goes in for second service, I guestimate it will have barely covered 11000 miles and I believe the plugs are a mileage related change not a time related change? Therefore me changing to Iridium plugs well before 18k, shouldn't cause any issues especially on a low mileage service plan which is what we'll have. I could of course be wrong though!.....

That's spot on. Manual states that the spark plugs only need to be changed at 18K and they're not time limited like the oil at 12 months if you do less that 6K p.a.

Still JRs test will only be for the eco driver. It wouldn't test the more spirited driver when 1.0mm gap can be put to the test.

 

[jrkitching]

To be fair when the car goes in for second service, I guestimate it will have barely covered 11000 miles and I believe the plugs are a mileage related change not a time related change? Therefore me changing to Iridium plugs well before 18k, shouldn't cause any issues especially on a low mileage service plan which is what we'll have. I could of course be wrong though!.....

Fitting Ir plugs will technically void the warranty but if you've taken the car in for a replacement failed suspension bush, I can't realistically see any FIAT mechanic digging down & removing them to check. In the (very unlikely) event of an actual engine problem, you could always just refit the original plugs .

From personal experience, I'd say the factory fit plugs will be past their best by 12,000 miles.

 

[jrkitching]

What is the difference in lenght on the projected tip compared to standard ?

About 2mm. Picture here.

How risky is it to remove the washer on the plug or replace with a much thinner one that wouldn't deteriorate.

Nice try, but I wouldn't risk it. Also, extending the whole body of the plug further into the combustion chamber would likely interfere with the gas flow, even if it didn't physically hit anything. I'd need to take the head off to see how the plug fitted before even thinking about this one, and I'm not feeling that experimental.

The next step is to run both cars for about 2000 miles & see what differences these plugs make.

 

[loveshandbags]

About 2mm. Picture here.

Just checking for the reference to Iridium on the US F500 cars and came across this from here.
For the 1.2 L 8V Fiat 500, Fiat is installing NGK ZKR7A-10 spark plugs as exclusive OE fitment. NGK has developed this 12mm diameter plug specifically for Fiat’s FIRE EVO and PDA engine families. It is anickel alloy plug with 5mm protrusion and 1mm gap setting.

How thick is that washer ?

 

[RobW]

Fitting Ir plugs will technically void the warranty but if you've taken the car in for a replacement failed suspension bush, I can't realistically see any FIAT mechanic digging down & removing them to check. In the (very unlikely) event of an actual engine problem, you could always just refit the original plugs .

From personal experience, I'd say the factory fit plugs will be past their best by 12,000 miles.

agreed

my Cinq Sporting consumed std plugs by 9000 miles, then fitted Denso Iridiums and they lasted years, even with nitrous :devil:

 

[loveshandbags]

About 2mm. Picture here.

You've correct on this. There's 3mm protrusion on the DCPR7E plugs so that comes to 2mm. Apologies for doubting you.

Spoke with NGK this morning and they have no plans to develop an Iridium plug for the 1.2. They said that a request would have to made directly with Fiat as the OEM to share costs on the development of one. Get the impression that it could take 4 years to develop one. As mentioned by your goodself with the emphasis now on more modern engines like the TA that ain't going to happen.

 

[RobW]

You've correct on this. There's 3mm protrusion on the DCPR7E plugs so that comes to 2mm. Apologies for doubting you.

Spoke with NGK this morning and they have no plans to develop an Iridium plug for the 1.2. They said that a request would have to made directly with Fiat as the OEM to share costs on the development of one. Get the impression that it could take 4 years to develop one. As mentioned by your goodself with the emphasis now on more modern engines like the TA that ain't going to happen.

check out for Denso equivalents

http://www.sparkplugs.co.uk/

i have basically the same 1.2 fire engine in my Cinq Sporting ang have iridium plugs

 

[loveshandbags]

check out for Denso equivalents

http://www.sparkplugs.co.uk/

i have basically the same 1.2 fire engine in my Cinq Sporting ang have iridium plugs

Covered back on an earlier post (Click here). Note the attachment.

Have used the IXU22 from Denso - impressive plug. VXU22 there for those who want to 'splash out'.
There are none that match the protusion of the ZKR7A plug and the Densos (like the NGK Iridium) have not got the correct gap of 1.0 being preset at 0.8mm. Although it in the case of the T-jet it's correctly gapped at 0.8mm the same as the OEM NGK which is an iridium plug.