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Any thoughts on what caused this?

  • Thread starter Thread starter TorchRed_4.0
  • Start date Start date Aug 21, 2021
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TorchRed_4.0

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Aug 21, 2021
#1
  • Aug 21, 2021
  • #1
Only piston that looks like this is #8. Been smoking super bad and burning tons and tons of oil for months. Finally pulled the motor and doing a total rebuild starting with taking the block to a machine shop. What do you guys think caused this in the first place?
 

nickyb

I gotta say i never painted my nuts, Never Ever
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#2
  • Aug 21, 2021
  • #2
That is what's called F.O.D.
Some object got into the cylinder that shouldn't have.
It caused damage to piston and bore.
Possibly a screw .
 
Reactions: JD1964 and revhead347

HemiRick

I'd be looking at jacking under the house
Jun 28, 2020
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Aug 21, 2021
#3
  • Aug 21, 2021
  • #3
some little piece of metal got in there
 

7991LXnSHO

wanna catch the space herp
10 Year Member
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#4
  • Aug 21, 2021
  • #4
I expected to see a dropped valve seat, but this is the wrong group to see that very often. It was an Unidentified Freaky Foreign Object - a UFFO.
 
Reactions: General karthief

CarMichael Angelo

my rearend will smell so minty fresh,
15 Year Member
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#5
  • Aug 21, 2021
  • #5
What is in the spark plug hole in the end chamber?
 

7991LXnSHO

wanna catch the space herp
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#6
  • Aug 21, 2021
  • #6
Serious answer -
Is the spark plug as bad as the cylinder, and did the electrode or more cause it?
 

v8stang289

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Apr 22, 2008
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#7
  • Aug 21, 2021
  • #7
CarMichael Angelo said:
What is in the spark plug hole in the end chamber?
Click to expand...
Looks like a spark plug non-fouler
 

CarMichael Angelo

my rearend will smell so minty fresh,
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#8
  • Aug 21, 2021
  • #8
v8stang289 said:
Looks like a spark plug non-fouler
Click to expand...
didn’t work…parts of the plug fouler fouled the cylinder.
 

revhead347

Apparently my ex-husband made that mistake.
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#9
  • Aug 21, 2021
  • #9
v8stang289 said:
Looks like a spark plug non-fouler
Click to expand...
It sure does. Probably the Dorman one in the "Help" section of the Autoparts store. Now for the real question, was it the chicken or the egg? Did someone put an anti-fouler in that hole because something had already damaged the cylinder, or did someone put an anti-fouler in there causing damage to the cylinder?

Kurt
 
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HemiRick

I'd be looking at jacking under the house
Jun 28, 2020
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Aug 22, 2021
#10
  • Aug 22, 2021
  • #10
The anti fowler is nothing but a spacer to move the plug out, nothing to break off. It was no doubt put in after the damage occurred.
 

KRUISR

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#11
  • Aug 22, 2021
  • #11
The oil in the cylinder/chamber I would guess is due to oil being sucked up through PCV system. In stock set up, the hose connects to intake right at cylinder 8. If the system is pulling excessive oil vapour or oil, it will pool in the #8 runner of the intake. The engine will then suck it into the combustion chamber, fouling the plug. I had a period of time without the screen in the lower intake (below the PCV valve) and I would oil soak a plug to the point of misfire in 2 hours of driving (I was daily driving at the time).

I agree whatever is in or blocking the plug hole looks strange and there is definitely damage from something bouncing around in the combustion chamber.
 
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TorchRed_4.0

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Aug 24, 2021
#12
  • Aug 24, 2021
  • #12
HemiRick said:
The anti fowler is nothing but a spacer to move the plug out, nothing to break off. It was no doubt put in after the damage occurred.
Click to expand...
I added the anti fowler because if you drove the car more than a few miles the spark plug become soaked in oil and would cause a misfire in cylinder #8. The anti fowler would make it last a few more miles but the spark plug would still get soaked in oil.
 

TorchRed_4.0

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#13
  • Aug 24, 2021
  • #13
KRUISR said:
The oil in the cylinder/chamber I would guess is due to oil being sucked up through PCV system. In stock set up, the hose connects to intake right at cylinder 8. If the system is pulling excessive oil vapour or oil, it will pool in the #8 runner of the intake. The engine will then suck it into the combustion chamber, fouling the plug. I had a period of time without the screen in the lower intake (below the PCV valve) and I would oil soak a plug to the point of misfire in 2 hours of driving (I was daily driving at the time).

I agree whatever is in or blocking the plug hole looks strange and there is definitely damage from something bouncing around in the combustion chamber.
Click to expand...
I added a defouler but that’s exactly what was happening, the spark plug would foul out and be soaked in oil after a few miles of driving.
 

KRUISR

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#14
  • Aug 24, 2021
  • #14
There is a rubber grommet at the back of the intake. The PCV valve fits in. If you pull out the grommet, there should be a mesh insert below it.



This captures some of the oil vapour and lets it drip back into the lifter valley.

If you don't have one, they are pretty cheap. I got mine at rockauto.

Looking at your pic of the cylinder head, you can see some of the oil residue on the next cylinder/combustion chamber, not as bad, but its there.
 

General karthief

wonder how much it would cost to ship you a pair
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#15
  • Aug 24, 2021
  • #15
I think that thing was smoking a fair amount too.
 

TorchRed_4.0

Member
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Aug 24, 2021
#16
  • Aug 24, 2021
  • #16
KRUISR said:
There is a rubber grommet at the back of the intake. The PCV valve fits in. If you pull out the grommet, there should be a mesh insert below it.



This captures some of the oil vapour and lets it drip back into the lifter valley.

If you don't have one, they are pretty cheap. I got mine at rockauto.

Looking at your pic of the cylinder head, you can see some of the oil residue on the next cylinder/combustion chamber, not as bad, but its there.
Click to expand...
I’ve checked that it definitely isn’t that. The smoking was so bad it was probably illegal to drive on public roads. It was burning atleadt a quart a day. Oil was just pouring into the cylinder and making the spark plug literally wet with oil.
 

TorchRed_4.0

Member
Mar 2, 2019
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Aug 24, 2021
#17
  • Aug 24, 2021
  • #17
General karthief said:
I think that thing was smoking a fair amount too.
Click to expand...
An insane amount.
 

JD1964

there is enough sticking out to grab on to
15 Year Member
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Aug 25, 2021
#18
  • Aug 25, 2021
  • #18
Whatever got in there and caused that damage was probably spit out the exhaust valve and could still be trapped somewhere in the exhaust system. If you ever take the exhaust off, maybe you could find it. Could be laying in the pipe somewhere or dancing around in the muffler. Theres always a slim chance it made it all the way out
 

91TwighlightGT

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#19
  • Aug 25, 2021
  • #19
This reminds me of working on my brother's '94 Explorer. He had the 4.0L OHV V6, and he would occasionally drive back and forth from Kansas City to St. Louis to come back home from College. The Explorer always had a bit of a spark knock to it, but generally was okay if you drove it like a normal human.

He made it back from KC one day with a significant misfire. No big deal, probably just a bad plug or wire, right? Pulled the plug and the end of the electrode was long gone - the spark plug had exploded in the cylinder. Putting a new plug in didn't fix it, and a compression test revealed a whopping 40 lbs. of pressure.

So, as a relative car noob at the time and wanting to take on a big project, my parents let him borrow their Explorer and my dad and I tore the head off over my winter break from high school. When we got the head off, there was a triangular chip in the exhaust valve. Never did find the piece of spark plug, and the piston wasn't hammered, so we had the head redone and put it back together. It ran for another 7 years before it developed a rod knock and got cash for clunker'd.

Foreign objects in the combustion chamber can make a fun mess.
 
Reactions: General karthief

CarMichael Angelo

my rearend will smell so minty fresh,
15 Year Member
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Aug 25, 2021
#20
  • Aug 25, 2021
  • #20
91TwighlightGT said:
This reminds me of working on my brother's '94 Explorer. He had the 4.0L OHV V6, and he would occasionally drive back and forth from Kansas City to St. Louis to come back home from College. The Explorer always had a bit of a spark knock to it, but generally was okay if you drove it like a normal human.

He made it back from KC one day with a significant misfire. No big deal, probably just a bad plug or wire, right? Pulled the plug and the end of the electrode was long gone - the spark plug had exploded in the cylinder. Putting a new plug in didn't fix it, and a compression test revealed a whopping 40 lbs. of pressure.

So, as a relative car noob at the time and wanting to take on a big project, my parents let him borrow their Explorer and my dad and I tore the head off over my winter break from high school. When we got the head off, there was a triangular chip in the exhaust valve. Never did find the piece of spark plug, and the piston wasn't hammered, so we had the head redone and put it back together. It ran for another 7 years before it developed a rod knock and got cash for clunker'd.

Foreign objects in the combustion chamber can make a fun mess.
Click to expand...
i think a triangular chink out of an exhaust valve is just a sign of a burnt exhaust valve, w/o any other influence.
 
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