Mechanics

CARBON FOULING SPARK PLUGS

1996 Mazda Familia • 4 cylinder FWD Manual • 65,000 miles

Ive just had my engine compression tested: 125-120-165-125. Mechanic told me its still good for now but best thing to do is pull down top for rebuilt then check for other issues inside!
My car is a 1996 MAZDA familia w/B6 DOHC 1.6 engine, manual trans, power steering, no ABS.

I didnt had any major problem w/the car its very reliable & still performs good on the road despite its age. Except fuel consumption; 6 KM/Li w/AC on & 9KM/Li w/out AC, both city driving.

From June to present this year I already consumed 2sets of new plugs due to carbon fouling(all). Tip was dry(grey) then powdery carbon on isulator but when rubbed its maple like golden brown not wet w/oil or gas though. Ive already replaced air filter & had oil changed but still the same.

Can seafoam motor treatment cure this issue w/my plugs. Mechanic didnt approve this, saying it may cause some serious problems. Also he told me I might want to have my injectors newly replaced cause my engine is running rich due to my low fuel consumption. Im planning to have my injectors serviced instead, using ultrasonic system injectors cleaning. Will this be good instead of replacement. I computed, service will only take 2,000 while replacement would be 15,000-18,000!

Thanks much.

Regards,
Robert Smith
Avatar
Robert.smith
November 16, 2010.



In my opinion you're an excessive fuel consumption is causing the carbon fouling of the plugs, which is the direct result of low fuel pressure, replace fuel filter and check fuel pressure.

Dr Loot
Nov 16, 2010.
Fuel filter is 7 months old while Fuel Pressure regulator was recently cleaned then o-ring replaced because it was leaking. I will check or replace my valve cover gasket. I noticed some oil residue under the edges of my head. What are your thoughts for my compression test, is it good or not. What are the boundaries to say that engine is still good.

Tiny
Robert.smith
Nov 16, 2010.
Well said. Thanks for the inputs. Will also have the injectors cleaned. I've heard about this ultrasonic injector cleaning, then have an emission testing to be sure!

Tiny
Robert.smith
Nov 17, 2010.