Quick 'n Dirty (Fouling Plug Fix)?

[Paul LaBar]

All,

Here goes - I have a 304 that's running on quite well on 7 cylinders. (That makes it a 266 BTW. Tom Walker would be so proud . . . I digress).

Anyway, the plug in #7 is oil fouling. The vacuum gauge consistently drops 2-3 pounds on that cylinder, and I haven't had time to do wet and dry compression tests to help me diagnose whether the problem is in the top or bottom end of the engine. I know that in the long run something will have to be done, but for now I'm wondering if there's a quick 'n dirty fix to alleviate the problem a little AND could there be any negative ramifications of getting this cylinder to fire in a degraded state? The manual suggests that a temporary fix to oil fouling is running a hotter plug.

I just put a completely new set of Autolite 303's (Oops! not 85's), wires, cap and rotor as part of a tuneup. The old plugs (except for this one looked pretty good). So, I know the spark is strong. I also have added some Sea Foam to the oil and run about 1/3 can through the carb to clean things up that might be carboned or sticking.

I know I should probably just ignore the problem for the time being since the engine works great otherwise, but I just can't help trying to cover all the bases (that the pocket book allows).

Thanks in advance for your help!

Paul

 

[Bill USN-1]

Does your truck smoke all the time or just on start up?

If it's just on start up then do a search for puff of blue smoke or something like that.
There are several good threads.
You may be able to do a simple fix, just takes a little time.
Clean the oil returns and replace the valve guide o-rings with valve guide seals.

If it smokes all the time then you may have to just go to the help section of the parts store and pick up the right size antifouler. It just has a hole in the end so the plug won't get oil on it but will ignite the fuel mixture.

 

[Paul LaBar]

Bill,

Thanks for your reply! There's not much visible smoke associated with this problem when the engine's running. I'll pay close attention when I first start it next time. The new plug has what seems to me like a shiny oily residue I can feel it when I pull it. The old one was covered with clumpy black crud that looked like oil fouling in the diagnostic pictures. You can feel the miss everytime you run the engine warm or cold and it's not intermittent.

So you think my symptoms sound like oil getting past the valve guides? (I need to do that compression test!) That might be good news! I'll definitely check out the antifouler - I've never heard of one. Man, working on these old 'binders is a real education.

Thanks Again!

Paul

 

[Bill USN-1]

Has any work been done on the heads that you know of.
The rocker arm bolts should also be sealed when installed.
Most lead right to the intake ports.


You can have some ride behind you and watch the tail pipes.
If it smokes on hard acceleration then it's probably the compression rings.

If it smokes when you let off from a hard acceleration(deceleration) then you could have worn valve guides.

If you have complete seperate dual exhaust then you can narrow it down to which side the problem is on.
But if it's just one plug(a back one) then you already know where the problem is.

 

[Paul LaBar]

Bill,

That sounds like an easy test (as long as you warn your assistant to expect quick starts and stops ). All I know about the engine is that it's a replacement for a 345 the previous owner had spun the cam bearings in. He found a rolled Scout II and performed a transplant. As far back as I can remember, the engine always ran a little rough, but since I've been giving what up to this point has been "my other scout" some TLC this problem has emerged.

BTW - I found this Non-Fouler online and assume this is what you meant: http://www.partsamerica.com/ProductDetail.aspx?mfrcode=RNB&mfrpartnumber=42000&parttype=743&ptset=C

I'm about to head out for RMIHR (wish you could be there), so I'm mostly looking for something to smooth out the engine for the weekend, and then I'll work on a more permanent fix. All your input is very helpful though and we've covered some ground I didn't find in any of the other "fouled plug" threads.

Thanks Again,

Paul

 

[J.D.Oldham]

I rebuilt a Ford engine for an "old guy" one time. It had 5 anti-fouler in a 6 cyl. That's the first time I ever seen them used, so I had to ask "what the Hell is that". He told me what they were for and said he didn't foul plugs anymore after install. He said he knew it was time to rebuild the motor when the last cylinder started to foul plugs. By the way, I had to bore the cyl. on that Ford to .040 because it wouldn't clean up at .030. P.S. I'm an "Old Guy now"

 

[Bill USN-1]

BTW - I found this Non-Fouler online and assume this is what you meant: http://www.partsamerica.com/Product...ype=743&ptset=C

That's them...
OBTW- I use the 18mm size for my O2 sensor threaded bungs that I weld to the exhaust!! (future ref when you go FI!!!)

Wish I was going to be at RMIHR.
But someone has to defend the world over here in Italy!!!

I enjoy meeting everyone we talk to on these boards, in person.
Makes it nice the next time you chat on here. There's a face with the msg!!

 

[Ozzie Binder]

G'day,
For a patch up job, try a hotter plug in that pot & also try side gapping ,works for me!!

 

[M J Gladd]

To Ozzie Binder: Please explain Side Gapping.

If hotter plug & anti-fouler can't prevent fouling, try switching plug with a good cylinder periodically before completely fouled to clean the crud off.

In any case, try to avoid adding a lot of miles on a non-firing cylinder. Flowing an unburned A/F charge can't be helping your cylinder lubrication.

Years ago there was a plug named Aldor that had a small additional spark gap inside the isulator. The extra gap caused the voltage to fire across the electrodes instead of bleeding down across the insulator. Had a bimetalic switch that would close the gap when the plug got hot from firing. Was a advertized as the spark plug with a brain.

Good luck

 

[kneemoe]

side gapping is just cutting part of the electrode off to get more spark expossed to the fuel-air mix. usually causes the spark plug to go bad a little quicker from everything i've ever seen/heard.