Who's Good At Reading Plugs?

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doc540

doc540

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"READING"

170, SS, .030 over, unknown mileage, 390 Holley on a Clifford Performance intake and cam.

lancer plugs1.jpg
 
I would run a compression test to see if it's just valves, but probably time for rings and valve job. Why? They are all over the place, not consistent patterns, color, etc.
 
I can tell that numbers 1, 4, and 6 plugs are wet and has some oil leakage. Prolly rings

2,3, and 5 look somewhat normal, don't see any white ash showing signs of a lean fuel mixture.

Any smoke blowing when the car is running?

Riddler
 
Looks like blown head gasket symptoms to me. (rotted around the water ports and compression rings on the gasket)
Of course it could be a lot more than that also.

I'd put money on the gasket being rotted away the most in these three places from what the plugs look like.

slant.jpg
 
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There's a cool Spark Plug Diagnostics chart inside the back cover of old Chiltons manuals. Maybe new ones too -- I haven't looked lately.
 
All the tube seals were bad, too.
I'm changing plugs and tube seals in the morning, then run it a while and check'em again.
 
TrailBeast said:
Looks like blown head gasket symptoms to me. (rotted around the water ports and compression rings on the gasket)
Of course it could be a lot more than that also.

I'd put money on the gasket being rotted away the most in these three places from what the plugs look like.

View attachment 1714970277
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Would it be using any water or oil if the gasket is rotted?
 
CudaChick1968 said:
True ... nicely done Beastie
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Thank you, now we'll see if it's actually the case. :D


doc540 said:
Would it be using any water or oil if the gasket is rotted?
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It could present a range of symptom from coolant loss, overheating, or even go as far as coolant and oil mixing in the engine and radiator both.
It looks like you might have a chance to catch it before then though.
Sorry that it's not better news, but experience tells me that's what's up.
One of the hints I see from the plugs is number 6 is greenish brown and shiny, and that is going to be where the gasket is the most rotted.
 
TrailBeast said:
Thank you, now we'll see if it's actually the case. :D




It could present a range of symptom from coolant loss, overheating, or even go as far as coolant and oil mixing in the engine and radiator both.
It looks like you might have a chance to catch it before then though.
Sorry that it's not better news, but experience tells me that's what's up.
One of the hints I see from the plugs is number 6 is greenish brown and shiny, and that is going to be where the gasket is the most rotted.
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Ok, so far no coolant loss, overheating, or mixing of fluids.
I'll keep an eye on it after I run this fresh set of plugs a while.

btw: some of the gaps were down to 20 or less
 
doc540 said:
Ok, so far no coolant loss, overheating, or mixing of fluids.
I'll keep an eye on it after I run this fresh set of plugs a while.

btw: some of the gaps were down to 20 or less
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20 or less with the buildup on them?
Normally the gaps wear larger.

If I'm right you are already getting small amounts of coolant in #1 and 6.
 
That's right, they wear larger not smaller!

BTW, I would expect the coolant passage rust through to stop are the edges of the coolant passages. I pulled a 52 year old head gasket and the passages were rusted open but no issues into the cylinders. Have you actually seen it also progress towards or into the cylinders?
 
nm9stheham said:
That's right, they wear larger not smaller!

BTW, I would expect the coolant passage rust through to stop are the edges of the coolant passages. I pulled a 52 year old head gasket and the passages were rusted open but no issues into the cylinders. Have you actually seen it also progress towards or into the cylinders?
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The slant 6 motors from decades ago that still run are notorious for the head gaskets rotting around those coolant passages.
As a matter of fact there was one here just recently that I also commented on.
Once the coolant area starts giving up eventually compression blows through the metal ring on the head gasket, and then compression starts leaking into the cooling system.
Not long after that you have coolant seeping back into the cylinder also.
The next step is coolant in the oil because the engine can't burn off the amount getting through.
Assuming the engine hasn't started overheating yet from all the exhaust bubbles in the system.
They "burp" out up to a point.
 
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Thanks for all your input

lancer plugs7.jpg


New seal, new plug, 50 miles at highway speeds, this is #4 before and after

I'll keep an eye on all of them as I put on more miles
 
well - from left to right - - 1st one says pion, 2nd one says champi, 3rd says cham, 4th says mpion, 5th says cha, 6th says on rn... what..?? :lol:
 
I think we have our little problem solved, and a valve adjustment was a big part of it.

All six look like this.

lancer plugs8.jpg
 
Pretty sure you have to cut the seal off the plugs, as the base of the drool tube is the seal..
 
JoeSBP said:
Pretty sure you have to cut the seal off the plugs, as the base of the drool tube is the seal..
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That is correct. No gasket is needed on the plug when you have drool tubes. Remove the gaskets.
 
I have seen many drool tubes with the base chewed up and cracked etc from not snipping the seals off..
 
I'm not really sure.
It was rebuilt in the early '80's, and I haven't tried to access the engine number which appears to be tucked behind a water hose.
 
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