Spark plug diagnosis, and "What is this part?"

[Hilderbrand1983]

My engine (1967 Dodge Dart 270 225cid L6 1bbl Holley carb) has been hesitating, probably misfiring, and threatening to die when cold for a few weeks now. This morning, on a whim, I decided to pull the #2 spark plug (just a random choice). It had dried oil near the sparking end of the plug. The #3 plug was the same. The #1 plug looked like a "normal" plug should.

NB: The plugs were installed new, by me, in early June of this year. They are iridium-tipped plugs (because I like replacing expensive plugs less often instead of cheap plugs more often). The washers have been removed, per usual for a slant 6 in '67.

I didn't think to take any pictures and ask questions until I pulled the #4 plug. I've uploaded pics of plugs 4, 5, and 6. What do you make of them? Is my fuel mixture too rich? Or is excess oil getting into my engine for some other reason? Does it need a total rebuild? And ... is it "worth it" to rebuild a slant 6?

Thanks ahead of time. You guys have always been so great!

 

[halifaxhops]

Yup a condenser.

 

[Hilderbrand1983]

Yup a condenser.

Thanks. What kind of condenser? It's clearly different from the one inside the distributor (which is the only one Rock Auto is pulling up).

 

[Hilderbrand1983]

Wait -- figured it out! It's for radio noise suppression. Doubtful that I'd need a new one, then.

Still concerned about the plugs, though.

 

[halifaxhops]

It is for the radio I believe. As long as it is not shorted it should be good.

 

[halifaxhops]

Could be just the valve stem seals need to be changed.

 

[halifaxhops]

Do a compression check if it is pretty good start chasing seals.

 

[Hilderbrand1983]

Could be just the valve stem seals need to be changed.

My brand new compression tester is coming tomorrow, so I get to put it to use right away!

I'm still very new to this, so thank you for your patience ... is replacing the valve stem seals something I can do with the engine in the car? Or do I need to pull it?

 

[pishta]

you can do it on car, you just have to have a mechanism to hold the valve up in the head, like a compressor into the spark plug hole or go old school and stuff rope in there and run the piston up slowly on compression stroke to jamb valves closed. Then you get a spring compressor (rent from autozone) and compress spring, pop retainer off and then you can remove spring and whats left of the umbrella valve seals. I bet there are none left.
As for iridium plugs in a non EFI motor, forget it, your tossing money into a fire. Just use stock OEM plugs and change them every 3 years...The iridium plugs are designed to run in an almost perfect stoich EFI environment so they lack the gusto to burn off the old tech crud that happens with a carb. Changing plugs in a non A/c slant is a walk in the park.

 

[Hilderbrand1983]

you can do it on car, you just have to have a mechanism to hold the valve up in the head, like a compressor into the spark plug hole or go old school and stuff rope in there and run the piston up slowly on compression stroke to jamb valves closed. Then you get a spring compressor (rent from autozone) and compress spring, pop retainer off and then you can remove spring and whats left of the umbrella valve seals. I bet there are none left.
As for iridium plugs in a non EFI motor, forget it, your tossing money into a fire. Just use stock OEM plugs and change them every 3 years...The iridium plugs are designed to run in an almost perfect stoich EFI environment so they lack the gusto to burn off the old tech crud that happens with a carb. Changing plugs in a non A/c slant is a walk in the park.

Thanks re: the spark plugs.

Would it be worth my while to just take the head off anyway? That way, I could replace the gasket (just in case it needs a new one), and it would be good for me to gain experience on something simple like a slant-6. Perhaps a good "winter" job?

 

[TrailBeast]

The very first thing I would do is to get rid of those plugs and put a standard NGK plug in it.
I have had WAY to many motors run like **** with those plugs, and a cylinder not firing like it should sucks oil.

 

[Hilderbrand1983]

The very first thing I would do is to get rid of those plugs and put a standard NGK plug in it.
I have had WAY to many motors run like **** with those plugs, and a cylinder not firing like it should sucks oil.

Thanks -- I went and bought me some standard plugs at AutoZone (some generic brand). I wanted to see if they would make any difference and, boy howdy, did they ever! Granted, I also treated the carb with some Berryman's B-12, but the combination of those two gave the car some pep like I haven't seen.

On the oil question ... I haven't managed to get to it yet, but when I bought the car, the oil pan, the front suspension, and most of the lower engine was covered in (what I assume to be) years' worth of oil-and-dirt buildup. Would this be caused by an oil leak? Or is it just a case of dirt having built up over time?

 

[TrailBeast]

Thanks -- I went and bought me some standard plugs at AutoZone (some generic brand). I wanted to see if they would make any difference and, boy howdy, did they ever! Granted, I also treated the carb with some Berryman's B-12, but the combination of those two gave the car some pep like I haven't seen.

On the oil question ... I haven't managed to get to it yet, but when I bought the car, the oil pan, the front suspension, and most of the lower engine was covered in (what I assume to be) years' worth of oil-and-dirt buildup. Would this be caused by an oil leak? Or is it just a case of dirt having built up over time?

Usually dirt over leaked oil after years of building up.

 

[Hilderbrand1983]

Do a compression check if it is pretty good start chasing seals.

Ok, so I just ran a dry compression test. Can you help me interpret these numbers (I know what they mean individually. Do they indicate something wrong with the piston rings or cylinders?)? The FSM says that cylinder compression should be between 110 and 140psi. The maximum variation between cylinders is 20psi. Here are my results.

Cylinder 1: 133psi
Cylinder 2: 130psi
Cylinder 3: 133psi
Cylinder 4: 125psi
Cylinder 5: 130psi
Cylinder 6: 118psi

 

[RustyRatRod]

ANy particular reason you're running platinum plugs in a slant six? That's kinda like rentin a thousand dollar call girl to go play put-put.

 

[Hilderbrand1983]

ANy particular reason you're running platinum plugs in a slant six? That's kinda like rentin a thousand dollar call girl to go play put-put.

Maybe I really like putt-putt!

Naw, I switched out for copper plugs yesterday. I didn't fully understand what I was buying / doing when I put the iridium plugs in.

 

[RustyRatRod]

There's nothing wrong with a higher end plug.

Here's the deal with them. Copper is THE best conductor. When you step "up" from copper to "something else" all you are doing is affecting the longevity of the plug. Nothing more. No hotter spark, no better performance, regardless if what all the marketing hype says.

The only one reason for platinum and iridium plugs is longevity. That's it. None of the "better" metals conducts as good as copper......although the difference is splitting hairs. Let the arguments fly, but that's the truth of it.

 

[Hilderbrand1983]

There's nothing wrong with a higher end plug.

Here's the deal with them. Copper is THE best conductor. When you step "up" from copper to "something else" all you are doing is affecting the longevity of the plug. Nothing more. No hotter spark, no better performance, regardless if what all the marketing hype says.

The only one reason for platinum and iridium plugs is longevity. That's it. None of the "better" metals conducts as good as copper......although the difference is splitting hairs. Let the arguments fly, but that's the truth of it.

That's why, in my initial post, I wrote that I got iridium plugs "...because I like replacing expensive plugs less often instead of cheap plugs more often...". Because it's not an EFI engine, though, it seems like the iridium plugs might be causing more problems than they're worth. Which is why I switched to copper plugs yesterday.

 

[RustyRatRod]

That's why, in my initial post, I wrote that I got iridium plugs "...because I like replacing expensive plugs less often instead of cheap plugs more often...". Because it's not an EFI engine, though, it seems like the iridium plugs might be causing more problems than they're worth. Which is why I switched to copper plugs yesterday.

Well hay, I even have double platimun Autolites in my 75 F250. In my defense, I got them off Ebay for .25 cents a piece. LMAO.

 

[pishta]

Take the car to a pressure wash car wash. Before you go, spray a whole can of Gunk engine Brite on the front suspension, Motor and oil pan. Once you get there, select the engine or wheel cleaner option a (not foaming brush, it usually comes out neon yellow at low pressure) and douse the front again, then hit it with soapy water and rinse followed by spot free rinse. That should knock the years of "slant six undercoating" off. If your going to pull the head, no sweat buy it weighs about 75 lbs. Remove the intake and exhaust as a unit, don't unbolt the bolts next to carb. Just the 2 exhaust head pipe bolts and the 15 or so triangle washer manifold bolts. You'll actually lose some compression and power using a replacement head gasket as the factory used a thin metal shim gasket which is no longer available. I wouldn't pull the head for general purpose with those compression numbers, just a valve seal job followed with a hot valve lash. Stock slants are butter smooth, have decent torque and are bullet proof but are no power houses.

 

[TrailBeast]

These are the motors that ran like crap with iridium plugs and perfect with standard NGK's
The 60hp outboard on my boat.
A KZ1000 street bike
My Fiat 124 Sport Spider (wouldn't even start)
A Ford straight 6 in my 66 Ranchero
Various V8's over the years

I always thought the plugs just had too cold of a spark, but I guess it could be something else although I don't know what.
Just swapping them out for standard plugs took care of all of the problems, so I never used them in anything again.

Wait, I think I might have used one set for slingshot ammo once.

 

[Hilderbrand1983]

Take the car to a pressure wash car wash. Before you go, spray a whole can of Gunk engine Brite on the front suspension, Motor and oil pan. Once you get there, select the engine or wheel cleaner option a (not foaming brush, it usually comes out neon yellow at low pressure) and douse the front again, then hit it with soapy water and rinse followed by spot free rinse. That should knock the years of "slant six undercoating" off. If your going to pull the head, no sweat buy it weighs about 75 lbs. Remove the intake and exhaust as a unit, don't unbolt the bolts next to carb. Just the 2 exhaust head pipe bolts and the 15 or so triangle washer manifold bolts. You'll actually lose some compression and power using a replacement head gasket as the factory used a thin metal shim gasket which is no longer available. I wouldn't pull the head for general purpose with those compression numbers, just a valve seal job followed with a hot valve lash. Stock slants are butter smooth, have decent torque and are bullet proof but are no power houses.

Thanks! The previous owner claimed that he had already replaced the head gasket, so the metal one is long gone anyway. Thankfully, though, it sounds like it just needs a valve job and we're good to go.