What causes spark plug to look like this?

[crypkilla]

bottom middle plug in the picture. white crusty stuff on the insulator tip and side electrode and oil everywhere else.

94 Ford Explorer XLT, 140k, pushrod engine with hydraulic lifters

compression 185-195 on all cylinders
clacking from that side of engine under heavy load
burns ~1.5 quarts between changes
possible loss of power (i’ve never driven another Explorer so idk)
No check engine light

What exactly might be causing this spark plug and noise issue? :blink:
loose wrist pin scoring cylinder wall? collapsed lifter? (but what about the oil?)

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• 2013-05-1215.23.06.jpg

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[Jamie]

While you’re at it just install some new plugs. Fords, like all domestics don’t require a very fancy plug. And unlike all imports you can pretty much use any plug that fits. They’ll be cheap as nails. Avoid Auto lite plugs. They’re just crap all round, I wouldn’t even put one in my lawn mower!

I would also inspect the ignition system also as well as run some injector cleaner through it. Using the higher octane fuel will help prevent the knock but you want to find the reason it did. Alot of cars will knock accross all cylinders if the timing is off, or the parts are worn enough. Carbon build up will cause a knock for sure, but it takes a fair amount of it. If there is a considerable amount of carbon build up no cleaner will remove it. You basically have to pull the head and scrub things clean with a scotch brite pad. Burning oil will absolutely cause carbon build up. Your engine isn’t a high compression engine so I wouldn’t consider the build up from using low grade fuel.

Now that you found the location of the oil leak I would:

Concentrated fuel system cleaner / Valve cleaner in half tank of high octane.
Change plugs
Top up oil
Go for a 2 hour drive on the highway keeping the revs up. IE if you have an O/D switch turn it off. This will give you lots of fuel spray that will clean off the valves and help clean the combustion chamber.

Run the rest of the fuel through and then fill up with your normal stuff to check for improvement.

I’m a big fan of the Valve Cleaner from Liqimoly. Up here VW/Audi dealers use all sorts of Liqimoly stuff that’s re bottled in VAG bottles. Works really good if used for maintenance. Its all TUV rated witch means more if your a european car guy. But like I said, if its really built up nothing else will remove it other than hard labour.

On the topic of Sea Foam I’ve never personally run it in any of my cars. But have been around a few while its being used. One car was the same as what I drive, known for deposits if you use a poor grade fuel. It certainly does smoke quite a bit. It did a nice job of cleaning up intakes and valves but as far as removing carbon deposits when the heads were pulled there was no change from before when we used a scope to look thru the spark plug hole. I’ve seen the same results from simply using distilled water, only instead of pouring it thru a carburetor its fed in thru a vacuum line.

Hope you get your truck solid again!

[EricTheCarGuy]

Good find! As for the detonation the EGR system is suppose to help with that. You might want to check it’s operation if you still have issues with that.

Keep us posted on any new developments.

[crypkilla]

[quote=”EricTheCarGuy” post=80529]Good find! As for the detonation the EGR system is suppose to help with that. You might want to check it’s operation if you still have issues with that.

Keep us posted on any new developments.[/quote]

so Eric is genius as usual and now it all makes sense. I had no CEL (check engine light) and since i dont have an OBD-I scan tool i never pulled codes. went to auto-parts store (this was all a few weeks ago) to use their tool and the one code i had was EGR flow insufficient. so when i had the whole top end apart to fix the oil leak, i fiddled with the valve and it seemed to be stuck. my vacuum hand pump wouldnt hold any vac. got it loosened up to where the vacuum hand pump would easily open the valve and hold vacuum.

this would explain why, now that i’ve fixed the oil leak, changed the spark plugs, and started running regular gas again, i still have some carbon knock, but not nearly as bad as it got just before i started running premium to reduce the knock. now my EGR is working again! i will pull codes again in a few weeks just to be sure (or i’ll figure out how to pull codes manually on this vehicle.)

so i still have yet to run Seafoam through the intake as suggested. this should help with the carbon buildup and hopefully solve my knock altogether. or close to solve it. it really is just a light knock now.

timing is accurate. plugs and wires are new (one wire had torn boot). valve are actually shiny clean on top (the forward most two at least.) as updated in my other thread, i will run seafoam straight thru the intake (forgoing for now the fuel inj cleaners in the gas tank) and report back! thanks for all the input guys!

other thread for reference (http://www.ericthecarguy.com/kunena/8-Service-and-Repair-Questions-Answered-Here/48096-accidentally-got-coolant-in-my-oil-little-help)

[EricTheCarGuy]

Cool, I’m glad you were able to get that fixed. As for the little knock that’s left, that might be compression differences in the engine. Going back to the plug pics you posted, a couple showed signs of oil contamination. That could mean that the rings are worn on those cylinders. If they are, then the engine won’t be ‘balanced’. If that’s the case, it might make noise under load. You could confirm this with a compression or leak down test. It’s great you’re making progress though.

Thanks for the updates.

[Author]

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