Hi guys,

I just took my 3 front plugs out to check wear, they have been in for 20,000 k's but look brand new! it seems the plugs are tooo hot!!! the electrode is white and the inslulator is also white as a ghost! there is no deposits of any type and dosent look like its the right plugs for this engine, the plugs are to manufacutre specification, which are NGK BKR5E-11 at 1.0mm gaping, or Champion RC10YCC4 at 1.0mm gapping. I have the NGK's running at the moment.

Has any one got an idea if these are the right plugs? im thinking of changin to cooler plugs, to avoid destroying a piston or somthin cause the plugs are too hot.

Thanks in advance

Kyle.

the plug isnt too hot,the combustion chamber is!,can be caused by a crook cooling system,bad fuel (low octane),blocked injectors or lean mixtures from what i know,what fuel do you use?,oxy sensor ok?,are you getting any pinking or detonation?

Steve

Im using normal unleaded, but in the 20 000 i have run premium unleaded for a bit, then swapped back to unleaded, when the price went up. might be the cause, i have recently put a batch of injector cleaner thru and changed air filter, fuel filter. the oil and filter is changed every 5000k's.

thanks steveo

Oh and it has a new radiator recently installed, so im not sure that would be the problem, it has sufficent coolant and the coolant temp sensor has been tested for faults. all working ok.

kyle

this might help you out, the pics aren't as clear as they could be but you may be able to find what is causing your problem.

http://www.mkiv.com/techarticles/read_plug/plugdiag.jpg

Thanks mate, i have a service manual with almost the same diagrams in it haha, but as the pictures point out, it is definalty looking the same as the too hot plug, ill load a pic of it, give me five mins.

could well be the injector cleaner leaving a coating on the plugs,ive had it but it is usually tan colour,but different cleaners may leave different coloured deposits,is the elctrode corroded like the pic or is it just "ashy"?,the plugs are the correct heat range for your car,so you should not need to go colder at all,if its not pinking i wouldnt be to worried myself,but thats me!,you could have a a worse problem!

sorry guys, its too late, ill have to get a pic in the morning, im flogged as it is haha. its 20 past 12 on the Gold coast :)

Check back later dudes for a pic of the plug!

Thanks dudes

could well be the injector cleaner leaving a coating on the plugs,ive had it but it is usually tan colour,but different cleaners may leave different coloured deposits,is the elctrode corroded like the pic or is it just "ashy"?,the plugs are the correct heat range for your car,so you should not need to go colder at all,if its not pinking i wouldnt be to worried myself,but thats me!,you could have a a worse problem!


mmm yeh true, the electrode does look like it has been red hot and coroding but not ashy, the insulator is too white for it to be normal, its not even a shade of brown or grayish???

its a weird one mate! i think youll be able to get a better idea when i upload a pic of one of the plugs.

37792

37793

That brown section on the insulator is nothing to worry about,This occurs due to electrical stress in the air near the insulator. (This is not a spark plug gas leak, for which it is sometimes mistaken),(taken from a denso site)

to me,that plug look fine and dandy,no pitting,melting etc,electrode is fine,but doesnt look to discoloured in that pic though!

I wouldnt be too worried about the way that plug looks, i've seen much worse.

thanks dudes,

i went to cheapa autos and they said they are totally perfect, and that the old graying or browning of the plugs was because of leaded fuel usually.

All good thanks for the help anyway

leaded fuel :bowrofl:

Yes true. The gray/tan deposits were due to leaded fuel and oil additives. CAT friendly engine oils, alcohol fuels and unleaded leave the insulator dull white. If its bright white or glazed glassy like the plug is too hot. Pepper specks and tiny aluminium balls mean its detonation.

Cheers, Alan

The wonders of ethanol will also produce this phenomenon - another thing into the mix I guess!