Fouled spark plug == end of the engine?

[DaddyToast]

98 Mounty 5.0 V8. Engine was running rough. Took it to the mechanic who hooked it up to the computer and saw cylinder #3 was misfiring. At first he thought it was a bad spark plug wire because the wire was right up against the Torque Monster header that the previous owner installed. But then he took out the plug and it was fouled. Pics here:

http://img42.com/n1CWC
http://img42.com/goBHx

At this point they got all somber on me like they were telling me about my own funeral. Like bad piston ring or valve seal. They didn't test compression or anything else. Can they make this diagnosis based solely on a visual inspection of the plug?

Basically they told me to put in a new spark plug and sell it, or spend $3-5k on a remanufactured engine (this one has 167k). This strikes me as a crappy thing to do to someone else, and I speak from experience because it is evidently the crappy thing which was done to me.

So other than doing that, what other diagnostics should I ask for or should they have suggested? Or is the visual evidence of that spark plug really all anyone needs to know?

 

[Bobmbx]

Your photos are locked, can't see them.

 

[DaddyToast]

Oops! Sorry. I didn't know how to unlock so here are new urls:

http://img42.com/n1CWC
http://img42.com/goBHx

THanks

(Edited to add that I've edited my original post to include these updated image urls)

 

[Flash]

Still can't see the pics.

I'm guessing the plug is fouled with oil?
It might be a valve seal or valve guide leaking or one oil control ring.

The valve seal can be done in situ, the guide would need the head to come off the ring would be a full teardown.

None of these conditions are fatal, you can just continue changing the one plug and maybe run a hotter heat range and use something like seafoam in the fuel.

I did that with a Chrysler 360 for a year until I pulled it and rebuilt it.

 

[DaddyToast]

Thanks, and sorry about the pics. I have no idea what i'm doing wrong. Maybe i'll try a different host because I'd really like some advice based on seeing what the plug looks like, since that's what they used to make their diagnosis.

 

[DaddyToast]

Fouled spark plug == end of the engine? (PICS added)

OK if these pic links don't work then I give up. Sorry. Thanks.

http://i1378.photobucket.com/albums/ah93/daddytoast1/DSC_0077_zpsbj7wgq2e.jpg
http://i1378.photobucket.com/albums/ah93/daddytoast1/DSC_0075_zps8vkxvloj.jpg

 

[DaddyToast]

Still can't see the pics.

I'm guessing the plug is fouled with oil?
It might be a valve seal or valve guide leaking or one oil control ring.

The valve seal can be done in situ, the guide would need the head to come off the ring would be a full teardown.

None of these conditions are fatal, you can just continue changing the one plug and maybe run a hotter heat range and use something like seafoam in the fuel.

I did that with a Chrysler 360 for a year until I pulled it and rebuilt it.

Hotter heat range meaning a specific type of spark plug? Can you suggest an example?

The mechanic said that I risked ruining the catalytic converter because of sending raw fuel down the exhaust. He said $900 for a new cat. Is this true? And will changing the spark plug every month (or however often I need to) allow me to drive without making things worse?

And also, any thoughts on additional diagnostics? Compression check, etc? I don't notice any smoke. I haven't looked at the oil. As far as I know, neither did the mechanic. I know I sound like an idiot, and it's because apparently I am.

 

[Flash]

Hotter heat range meaning a specific type of spark plug? Can you suggest an example?

A hotter plug will sink less heat allowing the tip to run hotter to help burn off the deposits.
Go to a parts store and tell them the numbers on the side of your plugs and ask for one that's one or two ranges hotter. Bosch claims their plugs spread over 3 heat rages, don't get Bosch plugs.

Plugs like the NGK Iridium have a very fine tip that doesn't foul up as easily.

The mechanic said that I risked ruining the catalytic converter because of sending raw fuel down the exhaust. He said $900 for a new cat. Is this true?

Yes. If the bad plug is allowing unburnt fuel to go down the pipe the fuel gathers in the cat a burns like in a furnance. This can slag the monolith causing a massive blockage. A clean plug will burn the fuel though.

And will changing the spark plug every month (or however often I need to) allow me to drive without making things worse?

Yes, it's tiresome though. The hotter plug and with a finer tip will help.

And also, any thoughts on additional diagnostics? Compression check, etc? I don't notice any smoke. I haven't looked at the oil. As far as I know, neither did the mechanic. I know I sound like an idiot, and it's because apparently I am.

What I would do is give it a full seafoam clean to get rid of built up carbon, it will probably need two treatments.

Then get a compression test and leakdown test to determine the health of the engine.

Is there ever any smoke on cold start up? That would indicate valve stem seal or guide leak.
No smoke at start up points toward an oil control ring.

The pictures work now.

I can see a lot of oil build up but I can also see another deposit which might be melted aluminium caused by detonation which would most likely be caused by the malfunctioning plug as well as a hot spot on the carbon build up.

See those little bubbles around the electrode? Scratch them off and try to determine what they are.
Is is aluminium?

You're not stupid; you just don't know about engines and you're asking the right questions.
You've also come to the right place to ask them, if I'm not right about something somebody who knows better will chime in.

 

[Flash]

How to do a Seafoam (or similar) clean.

Seafoam is only useful if you have a carbon build up. It's not a magic tune up in a can but if you do have a build up this stuff is great.

Somebody who knows the V8 better than I do should come in here now and say which vacuum line to use.

Warm the engine up and set it at a high idle.

Stick the vacuum line in the Seafoam can and let the engine suck it up but not too quickly.

When you're about 1/2 way down let the engine suck as much Seafoam as it can and let it choke on it and stall. This coats the combustion chamber with Seafoam.

I usually leave it overnight to soak and start it the next day.
It will smoke like a motherfluffer and really piss your neighbours off.

It would be best to find a highway as quick as you can and go for a high speed run to clear all the softened build up out and not let it linger in the cat too long.

It would be a good idea to stick another can in the fuel tank.

 

[Flash]

Does anyone know if the PCV would tend to clog number 3 piston more than any other?

 

[shucker1]

As for fouling #3 more than others it doesn't sound logical.

Looking at my intake set I have in the garage, PCV suction is actually tracked back to the upper plenum and the port is located really close to #4 lower runner.

However, remember the upper plenum is a very large cavity and anything is possible.

Daddy Toast, I totally agree with what Flash has said. Don't condemn the engine just yet. It could be something as simple as a bad plug wire causing the plug to foul out.

As for the comment about "Stupid questions" No Worries Mate!

That's why we are here.

 

[Bobmbx]

I'd start with new plug wires. There's a reason why the plug isn't firing, and thats causing the fouling. If you had an oil leak in the cylinder bad enough to foul the plug, you'd be blowing smoke from the exhaust pipe, mostly at start up, and your plug would look more like a dip stick covered with gooky oil goo.

How many miles on your current plug wires?

 

[DaddyToast]

Thanks for the responses everyone. I'll check into seafoam. New hotter plugs and new wires. The plugs that are in there now are Motorcraft AGSF32FM which according to this is a relatively cold plug, but I want to clarify what that means because I keep running across explanations like this: "Spark plugs with a high degree of heat dispersal are called high heat range (cold type) and those with a low degree of heat dispersal are called low heat range (hot type)."

High heat range = cold? Low heat range = hot? So exactly which type do I need?

I'll also have them test compression and check for leaks. I have not noticed any smoke coming out of the back when I start it.

I don't know how many miles are on the current wires. Speaking of wires, I need to call that mechanic back because before they pulled the plug and showed me the deposits, I could've sworn he said the wire was arcing because it was touching the header. The wires have little heat resistant fiberglass sleeves over the boots that supposedly withstand 1200F, but for how long? Anyway, after he told me the cylinder was burning oil, the arcing issue sort of slipped my mind. But will arcing destroy the wire? Is it caused by touching the header?

You guys are awesome, thank you.

 

[DaddyToast]

I also want to clarify about what the presence or non-presence of smoke at startup means.

This:

No smoke at start up points toward an oil control ring.

and this:

If you had an oil leak in the cylinder bad enough to foul the plug, you'd be blowing smoke from the exhaust pipe, mostly at start up, and your plug would look more like a dip stick covered with gooky oil goo.

Are these contradictory? Smoke = a bad ring? Or no smoke = a bad ring?

 

[Flash]

If you've got a bad ring it will smoke, maybe not enough to see while driving.

If you have a bad valve seal/guide the oil will drip into the engine when it's not running and there will be a cloud of smoke when you first start the engine also on engine overrun.

 

[jester1023]

If you the cylinder with the fouled plug is the same as the one with the arcing wire, it could most definitely be related. To explain without exact numbers...your ignition system, as well as all gasoline burning internal combustion engines, converts a 12 V DC current to a multi-thousand volts of energy that gets sent through the plug wires in search of ground. When a coil has an internal ground, it is shot. When a spark plug has a gap that is way too large (broken ground or eroded electrode), the high voltage will search for the path of least resistance to ground. That path is going to be found in the plug wire or coil. This is why quality plugs are a good idea, as well as keeping tabs on their condition. Now to the wires. Spark plug wires have 3 major components; conductor, insulator and connections. If the conductor is compromised, the voltage will typically arc across the break...not always, but normally. If the connector fails, again internal arcing may occur. Neither one of these compromises show up in short order, for the most part. If the insulator is damaged, you may never notice...as long as there is no ground close enough for arcing. If there is a close ground, the high voltage will arc to ground before it makes it to the spark plug. This greatly reduces the intensity of the spark in the combustion chamber...which causes the air/fuel charge to get a partial burn. This partial burn will start to cake as deposits on the heat source (spark plug), thus fouling the plug...compounding over time. The short answer is YES, an arcing plug wire can and will cause a spark plug to foul.

 

[DaddyToast]

If you've got a bad ring it will smoke, maybe not enough to see while driving.

If you have a bad valve seal/guide the oil will drip into the engine when it's not running and there will be a cloud of smoke when you first start the engine also on engine overrun.

Previous owner had recently re-registered it and it passed smog I want to say 2-3 months ago. Do you think it would pass smog with a bad ring? Of course maybe the problem has cropped up since then.

 

[DaddyToast]

Thanks Jester, great explanation about spark plugs, wires, arcing, etc.

 

[Flash]

Previous owner had recently re-registered it and it passed smog I want to say 2-3 months ago. Do you think it would pass smog with a bad ring? Of course maybe the problem has cropped up since then.

It shouldn't pass a smog test if it has a bad oil ring but I'm not familiar with the tests.