NGK Plugs

I've had exactly this problem on my Harley. Not one, but two new sets of NGKs (true, possibly from the same batch), still the same misfiring. Finally put an old set back in and it hasn't missed a beat since. In fairness, old set were NGKs also, and a new set in my Ford Ka have given no problems. There just seem to be a lot of duds around!

Russell

NGK have a very good name. I'd send them back. Where did you buy them - any chance they are fakes?

I've had NGKs leaking compression (brown streaks up the insulator), but that was 10 years or more ago. I have NGK iridiums in my MX-5 now and they're fine, as were the plain NGKs before them.

Got them at my local motor factors they have been very helpful in the past and I will be taking them back, I am not putting down NGK as I have used them before but I have heard from others which have had this happen so I thought I would post my experiences just in case others start changing more expensive parts before go for the plugs, just for everyone's information if it helps..

Rich

The NGK spark plugs may have been resistor types, e.g. used in Saabs with Direct Ignition. In fact if NGK is specified for a Saab with DI, then no other type should be used since the control system is designed around this type of spark plug. Sorry for this diversion, I know you have a Sierra, but just illustrates that you should be careful with the choice of plugs outside the manufacturers optimal specification for a modern complex engine management system.

Which part of a Pinto lump is 'modern and complex'?

:-) But it could be the other way round, i.e. plugs were resistor types?

"Rich" wrote

Ford recommend Champion RF7YCC or RF7YC plugs for this engine.

There is an "urban myth" that says NGK and Bosch plugs are "better" than Champion. They aren't. And in the 2.0 Pinto unit, they are particularly poor.

Urban myth or not, in my 45 years of playing around with the internal combustion engine in many forms, road race and rally, the *only* make of plug that has regularly failed prematurely is Champion.

FWIW, Ford engines always seem to do better on Motorcraft plugs.

YMMV :-)

Chris

"Chris Whelan"

wrote > FWIW, Ford engines always seem to do better on Motorcraft plugs.

Motorcraft is Ford's "own-brand" but I don't know if Motorcraft actually manufacture anything or whether they are simply Champion/NGK/Bosch etc re-packaged.

In message , Knight Of The Road writes

Recent Motorcraft plugs for the European market are manufactured by NGK.

My local mobile tuning guy would disagree with you. On a daily basis he fits a lot of new plugs. While he was using Champions, every month or so he'd have a box of faulty plugs to send back to the wholesaler for credit, or replacement. It was costing him money, as some were failing soon after being fitted. Meaning a second trip to the customer to sort the problem. Some time ago he changed to using NGK, and since doing so hardly ever sees a faulty new plug. Possibly Champion plugs are no 'better' than NGK, but from his experience, it would appear that NGK's quality control is superior to that of Champions. Mike.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Chris Whelan saying something like:

See below.

That exactly follows my own experience of them.

Champion may be better than they were, but they used to be s**te.

The version widely circulated when I was working in the motor trade about 30 years ago was that only Bosch or NGK plugs should be fitted to alloy heads because of the risk of other brands seizing and stripping threads.

I still generally follow that advice. The only thread seizures I've had have been Champions.

I recently spotted this text in a Bosch plug catalog I downloaded, suggesting that there may still be an issue:

"Nickel-plated spark plug shell and plug thread prevent corrosion and seizure of threads in aluminium cylinder heads"

John

I have had a set of ngk plugs in my astra for about 4 years and they still work lovely.

Gra