What could cause spark plugs to foul up?

[optimusp517]

Just had them changed maybe 6 months ago and when I step on the gas to accelerate hard sometimes it bogs and now I changed them out and problem solved, but the real question is what's causing them to foul up like that?

Recent Maintanence from previous year:

- Spark Plug wires
- O2 Sensor replaced
- New Spark Plugs

That's pretty much it.

[jlevie]

Excess oil consumption (worn rings or bad valve seals), excess fuel consumption (excessive fuel pressure, leaking injectors, oversized injectors), misfires, or partially plugged catalytic converters are all possible causes.

[nando]

are they platinums?

[deutschman]

google this and you will find a lot of info... http://www.gnttype.org/techarea/engine/plugs.html

[AndrewBird]

Plugs should be changed at every other oil change, so ~every 6 months. They are a wear item you know.

What do you mean by fouled anyway? You can foul from too rich a mixture or too lean a mixture or from just being old.

[devonjordan]

Plugs should be changed at every other oil change, so ~every 6 months. They are a wear item you know.

What do you mean by fouled anyway? You can foul from too rich a mixture or too lean a mixture or from just being old.

That often? WOW, that just seems excessive to me...

[nando]

maybe on 1960s engines, but I think M20 plugs last quite a bit longer than that.

[optimusp517]

Fouled up meaning it bogs my car when I drive, but when I replaced them this afternoon the car drove like a champ.

And referring to above I'd think plugs last a lot longer than 6 months even 1 years. Well I'll have to see what happens in another 6 months and go from there. Man could be many things, but oh well for now...

[SpecM]

maybe on 1960s engines, but I think M20 plugs last quite a bit longer than that.

I think BMW said they were good for 20,000 miles

I change mine once a year

[MrWizard]

Too much fuel, weak secondary ignition or oil control problems (rings or valve guides/seals)

Approximately 15K (Inspection Service) change interval

[optimusp517]

Speaking of too much fuel. How much do you guys get ona tank of gas? Average. I know everyone's driving habits is different. I mash on it once in a while, but I only rack up maybe 210/tank the most. What are you guys getting on average?

[robmespeedy]

On my Eta i was getting 280-300

[nando]

Speaking of too much fuel. How much do you guys get ona tank of gas? Average. I know everyone's driving habits is different. I mash on it once in a while, but I only rack up maybe 210/tank the most. What are you guys getting on average?

that's pretty poor, about 14 miles per gallon assuming a 15 gallon fill up (driven to the reserve light). you should be getting at least 270 on a tank, conservatively.

[optimusp517]

that's pretty poor, about 14 miles per gallon assuming a 15 gallon fill up (driven to the reserve light). you should be getting at least 270 on a tank, conservatively.

Crap who's going to help me fix the issue or help me locate it? That is really bad! I wonder what it could be... at this point. Where would you guys suggest first?

[Liam]

Crap who's going to help me fix the issue or help me locate it? That is really bad! I wonder what it could be... at this point. Where would you guys suggest first?

Check your fuel pressure and check the regulator's vacuum like for fuel leaking out of it.

Did the spark plug cables have a sensor on the #6 plug? If it's DME 1.3 and this isn't working it will not fire the injectors semi sequential and may cause this.