Cleaners For Spark Plugs

[Tham]

I don't have one of those motor-operated or sand-blasting
type cleaners, so I have been using carburettor cleaner to
flush out fouled spark plugs.

I wonder if the carb cleaner may be corrosive to the
ceramic insulator or other parts of the plug ?

The number 2 and 3 plugs foul often due mosty to worn
valve seals, so I take them out every now and then to
clean them as a stop-gap measure.

The circular gap between the lower ceramic insulator
and the inside of the thread shell gets gummed up with
carbon deposits, so I spray carb cleaner into there to
try to loosen and flush them out, then try to dig out the
remainder at the bottom as much as I can with a small
allen key.

The plugs were reusable after the first few flushings. However,
after the last cleaning, they appeared to have intermittent
misfiring.

If carb cleaner is too strong, how about one of those multi-purpose
cleaners like the WD40 and similar products, "dry" type electronic
contact cleaners like those CRC products, Philips DCS390 contact
cleaner/degreaser (below) or even engine degreasers ?


http://www.sanace.com/Spray_Cleaners/pspray_dcs.html


Thanks.

[fixeruperer]

carb cleaner will be fine, but its normal for fouled plugs not to come back.

you could put some hotter plugs in to aid with the oil burnt fouled plugs, but ultimately you should fix your motor.

["Z" UTE]

Unfortunately scraping the carbon from the root of the insulator is probably scratching the ceramic surface, leading to a loss of insulation. Check your spark plug catalogue at the parts shop, and go up a couple of heat ranges.

cheers Chuck.

[Tham]

Thank you for all the good info.

Yes, I believe that scraping the carbon at the root of
the ceramic insulator would be scratching it and cause
a loss of insulation, which may well tend to make it misfire.

And I understand it is also unlikely for a fouled plug to
be properly cleaned and revived back to new.

I am already using NGK BP5ES, and I think the hottest
is BP4ES. Unfortunately, Malaysia has a poor selection
of spark plugs on the market. The motorists nor the parts
shops here don't seem to know what hot or cold plugs are.

The only ones they have been selling here over the past
20 years or 30 years are BP5ES and BP6ES. Same for
Nippondenso, only W16EX-U and W20EX-U are available.
Bosch too, just W8DC and W7DC.

I guess I will have to replace the valve seals sooner or later.

[oldcorollas]

sooner rather than later?
or swap plugs every 2nd cleaning...

[Tham]

sooner rather than later?
or swap plugs every 2nd cleaning...

I took out the plugs yesterday and cleaned them
with CRC contact cleaner this time.

http://www.crcind.com.au/catalogue.n...r?openDocument

This appeared to be more effective than carb cleaner
and the engine seemed to idle better and run smoother
after that.

However, I couldn't see any loose carbon or sludge draining
out from the insulator root. I wonder where it all went. In fact,
nothing seemed to drain out, it's that quick-drying.

Electronic contact cleaners don't usually leave any residue.
The outside of the thread shell felt cold after that, wonder if
they use liquid nitrogen or something.


Can I swap the fouled Number 2 and 3 plugs with Bosch W8DC,
and mix them with the NGK BP5ES on number 1 and 2 cylinders,
next time around ?

The Bosch plugs seem to be a bit less subsceptible to fouling.