Oil in my Spark Plugs

[Anonymous]

I own a 66 Bronco with a 170. I have owned the truck for about 1 year and have spent the majority of th year doing body work. The few times I have had it on the road it ran well. Throughout the year I have started the engine and let it run for 20-30 min. I recently observed oil on one of my spark plugs at the base. The engine is very clean and so this cought my eye. I pulled the plug and it was wet w/ alot of carbon. I pulled others all had carbon and at leat two others were wet. I replaced the PCV although it did not seem clogged or stuck. I changed the oil (added 7 qts of 10w 30) and the old oil seemed in good condition dark coffee no cream. I also replaced the plugs. The plugs were supposed to be pregapped, but did not seem to be at all - I set them to .034 so my feeler guage moved easily, but no up down motion. I now seem to have increased oil pressure from about 30psi to about 40psi. The engine still runs very nice - and I never had white smoke blow out the back except at start up after sitting. Should I be worried about the oil pressure? I was rushing with the plugs, should I go back and double check the gap? If this does not correct my oil on the plug problem at what point should I be concerned and not rn the truck? I know other potential caused could be valves, piston rings, or the cylinder head, but am at a loss as to how to narrow this down. Should I not drive the truck at all until I figure this out? Thanks in advance and yes for a first post I know it is long.

 

[Lazy JW]

Are you certain that thing takes seven quarts of oil?

Welcome to the forums!
Joe

 

[Anonymous]

Yes - it seems like alot - the shop manual lists 7qt for the bronco 170 and 4 1/2qt for the econoline in the oil pan capacity chart. The chilton's lists 7qt crankcase w/filter in the capacities chart.

 

[CZLN6]

Howdy Back:

If the engine has the original oil dipstick, verify that the crankcase is not over full of oil.

40# of pressure at idle is not at all bad, quite good. Does pressure go up as rpms go up? Is the wetness on the plugs from oil or gas/rich? Try this, get the engine warmed up and take a 10 - 20 mile drive at highway speeds. Without alot of idling stop the engine and do a plug reading. IF they are black and oily, you have a worn engine. It could be as simple as valve stem seals, or more involved.

Try this.When going down the highway at say 55 mph, leave the car in gear and take your foot off the gas and let it coast down to 35 mph. Then step on the gas to accelerate back to 50 while watching your rearview mirror. If you see a cloud of blue smoke, you likely have a valve stem seal problem. Replacing the valve stem seals could make a big difference.

Also check to see that your needle seat in the carb is sealing correctly. If you smell or see gas on the carb when you shut off you are likely leaking raw fuel into the manifold too. Make sure your choke is not sticking open too.

IF the engine is just , in general, wornout, you can try a step hotter heat range spark plug to help burn off the oil contamination. Always check the gap on new plugs to verify. Trusting "Pre-gapped" is not for us. What brand of plug and heat # did you put in?

If cylinder pressure is fairly equal in all cylinders, I would not worry about continuing to drive it. Wearing out is a very slow process. Burning some oil is one symptom.

Adios, David

 

[Anonymous]

Will do all of the above. The plugs are Autolite. Can't road test right now, I had a leak in my exhaust manifold gasket that I had been putting off until today - everything came off good, but the manifold surface is not too smooth. alot of hardened carbon and pitting that isnt comming off with a wire brush - any recommendations before I put this thing back together?

 

[pedal2themetal45]

Please check the dip stick for the oil level.... I've worked in service stations & car/trucks sence 1966 and NO car or truck (big V-8 or I-6 or V6) took more than 5 qts w/ filter. A big truck may take 6 qt.
The oil on the plugs is most likely the valve cover gasket. don't overtighten the valve cover bolts or it well push the gasket out causing a leak... only hand snug.
The carbon on the plug is most likely nothing to worry about as sitting and just idleing could cause this .. car (bronco) needs taken out and run.. and it should clear up.. if not might have to rejet the carb..
just my .o2
Tim