#5 plug is fouling out (1 Viewer)

[tonkota]

This has been an on going problem for me. It happened with the 3F-E, and now it's happening with the 2F-E. The head was rebuilt and checked for cracks, I used an OEM head gasket, and it runs great till that plug is clogged up. And it's only the #5 plug. I use NGK plugs.

I have a theory about the little coolant lines that run in the 3F-E intake. I think that there may be a crack there and the coolant is slowly getting burned off.

It may be a head gasket, but I really doubt it. The oil has no water in it, and the coolant has no oil in it.

Should I take the coolant lines from the intake, and spray some carb cleaner down there to see what happens?

Thoughts? I am really lost on this.

 

[cahilc]

Jsut spitballing here, but ...

Even compression test across the cylinders ?

KV (resistant) test your number 5 plug wire ? Compare to others ?

Cahil

 

[tonkota]

I have not done a compression test, but this 2F short block only has 622 miles on it. I replaced the wires today. The old ones (Bosch) were really loose fitting.

Maybe I'm just paranoid and the rings aren't set yet?

 

[Tinker]

What's it fouled with?

 

[Slow N Steady]

Retorque the Head. Had the same thing when I put mine together, just mine was low on Cyl. #1. The compression (hot) was (1-6) 100, 120, 140, 140, 135, 140, 145. Now, after the retorque, they are all pretty much 140 to 145! And that's with 188k on the bottom end. A Compression check is a MUST. Spend the $$ at Sears and pick one up. Then, while you are at it, pick up a couple of guage pods and fill them with a Vacuum Guage and a Mechanical Temperature guage. These will save you thousands of $$'s. Now, if only I could get my wobbly rear drums sorted out ...............Good luck!

 

[woody]

IIRC, the brake booster draw's it's vacuum directly above #5...I recall reading that bad boosters = burned valves on #5/#6....

 

[tonkota]

I did re-torque the head after it had been warmed up. Each bolt did turn just a bit.

If the brake booster is bad, would the brakes be tougher to push than normal?

The plug is fouling with "contamination" of some sort. Autolite's web site has a pretty good set of pictures of plugs with different type of problems. Mine looks like #9 and #10.

http://www.autolite.com/tech/PlugTips.pdf

Thanks for the help so far!!

 

[woody]

pull the vac hose off the booster and plug it tight....start the vehicle, and see how it runs/idles....if it's different than with the booster hooked up, it's possible it's bad...next step is to vac-test the booster with a pump, see how it holds suction.

Outta also note braking, if pulling the booster hose doesn't make a major effort change in the braking, the booster may be questionable...

damn, with I could remember where I read the booster deal tho....