[335i E92]

Hi

Gonna change the plugs on my remaped 335i, is it nessesarry to gap them?

With the car being mapped is it a good idea to close the gap slightly to assist the additional fuel & air?

Also how often is it recomended we change the plugs when remaped, every 15k to much?

Cheers

[creepy coupe]

Check them as a matter of caution, but I don't see the need to change the gap from the recommended.

Modern plugs are good for 20k+

[Dr Dave]

Plugs come with tip protectors on, aslong as they are handled and installed correctly there is no need to gap them.

I wouldn't alter the gap in this case in point.

Most modern plugs are good for 5yrs/60,000 miles, so I'd not overly worry. 15k seems a little premature imo

[Jon D]

Regardless of tip protectors, I would always check before installing them - it's not exactly a major operation to run a feeler through the gap and the resulting peace of mind is worth the effort.

[335i E92]

Cheers guys...

I know they come pre-gapped at the correct setting, just wandered if it was worth closing the gap slightly to compensate for the higher fuel & air mix.

Think I'll leave them at the standard pre-set gap.

[DavS1]

check gaps as a matter of course, generally on turbocharged cars depending on power/boost they'll have a smaller gap than an N/A car, but not a huge issue on cars with coil on plug ignition. on a cosworth for instance running like 1.5-2bar boost you'd run a .6thou gap, which is small but the old ignition system and high boost means you'd likely have a missfire issue with the boost blowing out the not so strong spark.

[Jon D]

Originally Posted by DavS1

...you'd run a .6thou gap

.6 thou gap? Even if you're talking imperial, that's 0.0006" - about 1/3rd the diameter of a human hair! Apart from the fact that the electrodes would be virtually touching and therefore not producing a spark, I think you'd need a microscope to check it .

[DavS1]

my mistake, I meant .6mm - .24thou.

[m1bjr]

Originally Posted by 335i E92

Hi

Gonna change the plugs on my remaped 335i, Cheers

How were the originals and do you know the mileage they covered?
Got any photos for the record?

Im up to 60k plus with no indication in the iDrive or service logs of them being done before.
They are showing in CBS due in about three light years, so am not at all convinced they are all original.
Car runs okay though, even on the map for the last year.

What interval are they normally showing up for first change?

steve

[335i E92]

Originally Posted by m1bjr

How were the originals and do you know the mileage they covered?
Got any photos for the record?

Im up to 60k plus with no indication in the iDrive or service logs of them being done before.
They are showing in CBS due in about three light years, so am not at all convinced they are all original.
Car runs okay though, even on the map for the last year.

What interval are they normally showing up for first change?

steve

Hi Steve

I tend not to stick with BMW service schedules as like you I'm running a remap and I'm also planning to keep the car for a good few years. Which is why I fited an AR design catch can and I drop my oil every 5-7k, for me £100 every 6 months or so gives me peace of mind. BMW's 20k oil changes are way too long!!

If you go by BMW the plugs are good for 60+k, I have an awesome Indy BMW garage so servicing doesn't come at a rediculous price. My plugs have only been in for 20k but again for the sake of £90 fitted every 18 months or so it's
a small price pay to keep it running like new.

I might be being over cautious but as I said a small price to pay for peace of mind.

[m1bjr]

Originally Posted by 335i E92

My plugs have only been in for 20k but again for the sake of £90

I might be being over cautious but as I said a small price to pay for peace of mind.

I agree.
Which is why I'm curious to see how they look at 20k

[335i E92]

Originally Posted by m1bjr

I agree.
Which is why I'm curious to see how they look at 20k

It's going in on Thurs, I'll ask them to box up the old ones.

I'll report back on Thursday eve on the condition, try n get some pics too.

[m1bjr]

Originally Posted by 335i E92

It's going in on Thurs, I'll ask them to box up the old ones.

I'll report back on Thursday eve on the condition, try n get some pics too.

Thanks mate.
I just ordered a set for tomorrow.
Been bugging me but ICBA to pull them out without having spares so thought sod it.
I'll pop some pics up too soon

Failed tips can do a mahoosive amount of damage. Not worth the risk and can only improve its smooth running/economy.

[xenon]

They're all four-tip plugs aren't they? I know mine are so not really "gapable" anyway in the traditional sense.

[Jon D]

Originally Posted by xenon

They're all four-tip plugs aren't they? I know mine are so not really "gapable" anyway in the traditional sense.

You can gently bend the four ground electrodes toward or away from the centre electrode, thereby varying the gap.
Chances are that the tip protector will have precluded any displacement but, unless the gap is stated on the packaging, you're not going to be certain what it is and it's a very easy thing to check with a narrow tip feeler - did someone else mentioned peace of mind? .

[Dr Dave]

You can't adjust nor accurately measure the gap on a multi-electrode platinum tipped spark plug - you'd need curved feeler gauges, which simply don't exist as far as I'm aware.

[Jon D]

Originally Posted by Dr Dave

You can't adjust nor accurately measure the gap on a multi-electrode platinum tipped spark plug - you'd need curved feeler gauges, which simply don't exist as far as I'm aware.

You're absolutely correct in assuming that curved feelers are a rare breed. However, wire feelers are available for applications such as the one in question.
If you're unconcerned just screw them in without checking. Personally speaking, I'd always check to see it they conform to the manufacturer's spec before fitting .

[Dr Dave]

I wonder how many BMW techs possess wire 'feelers?

[Jon D]

Originally Posted by Dr Dave

I wonder how many BMW techs possess wire 'feelers?

Pretty standard equipment - to anyone who knows what they're doing .
http://www.nicotine.anonymous.org/to...ogs/Gauges.pdf
or: http://buy1.snapon.com/catalog/tools...e=snapon-store
In other words - not as rare as some would like to think .

[335i E92]

Update...

Had the plugs changed today. Speaking to the ex BMW head tech who runs my local Indy the plugs are 3 pin an pretty much none adjustable as there are no feelers available.

The plugs that they took out had been in for 17k of which time the car was mapped. They looked well used with blacky brown deposits on all three prongs and according to the tech were well worth chaning. As some of you know I had alot of problems with my car when it was 1st mapped which caused it to run rough for a few months, I suspect this is why were looking worn.

The cars now running even smoother than before so £85 well spent. As I said the wear was probably caused when the car was running rough but for £85 it's worth changing them before the recommend BMW schedual, imo!!

H

[DavS1]

85 quid, ouuuuch. I thought 45 was bad for a set of platinum/irridium plugs!

[bizzleb109]

I ended up paying a £104.00 for a set of 6 plugs from a stealer.