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Spark plug diagnostic question

  • Thread starter Thread starter 02vertable
  • Start date Start date Jan 22, 2019
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    fox help spark plugs

02vertable

Member
Aug 7, 2018
50
3
8
Queen creek Arizona
Jan 22, 2019
#1
  • Jan 22, 2019
  • #1
This doesn't look right, is it oil fouling, what do you guys think?
 

90sickfox

Wasn't a pretty sight...and I've got big hands
SN Certified Technician
Mar 2, 2015
6,945
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Jan 22, 2019
#2
  • Jan 22, 2019
  • #2
That's a sign of oil being in the combustion chamber....

What cylinder was that and what engine ?
 

02vertable

Member
Aug 7, 2018
50
3
8
Queen creek Arizona
Jan 22, 2019
#3
  • Jan 22, 2019
  • #3
90sickfox said:
That's a sign of oil being in the combustion chamber....

What cylinder was that and what engine ?
Click to expand...
5.0 ho out of my 1991 mustang. That was cylinder 5. I figured it was oil fouling, I think its valve seals.
 

CarMichael Angelo

my rearend will smell so minty fresh,
15 Year Member
Nov 29, 1999
10,641
8,909
234
Birmingham, al
Jan 22, 2019
#4
  • Jan 22, 2019
  • #4
Hudson N said:
5.0 ho out of my 1991 mustang. That was cylinder 5. I figured it was oil fouling, I think its valve seals.
Click to expand...
That spark plug looks like its been in the engine for 12000 miles.

It would be wet if it was fouling. It looks to be neither fuel, nor oil. Most likely carbon
Build up.
If the engine eats oil enough to foul a plug, it'd smoke as well I think.
And unless you've either did a leak down test ( preferred) or a compression test to determine overall consistency between cylinders, I'd think twice before pulling anything apart.
 

02vertable

Member
Aug 7, 2018
50
3
8
Queen creek Arizona
Jan 22, 2019
#5
  • Jan 22, 2019
  • #5
CarMichael Angelo said:
That spark plug looks like its been in the engine for 12000 miles.

It would be wet if it was fouling. It looks to be neither fuel, nor oil. Most likely carbon
Build up.
If the engine eats oil enough to foul a plug, it'd smoke as well I think.
And unless you've either did a leak down test ( preferred) or a compression test to determine overall consistency between cylinders, I'd think twice before pulling anything apart.
Click to expand...

She smoked a little. But replaced my PCV and it hasn't smoked much since. Should I put some new plugs in, factory plugs instead of those Bosh plugs the previous owner put in?
 

CarMichael Angelo

my rearend will smell so minty fresh,
15 Year Member
Nov 29, 1999
10,641
8,909
234
Birmingham, al
Jan 22, 2019
#6
  • Jan 22, 2019
  • #6
Hudson N said:
She smoked a little. But replaced my PCV and it hasn't smoked much since. Should I put some new plugs in, factory plugs instead of those Bosh plugs the previous owner put in?
Click to expand...
yep
 

90sickfox

Wasn't a pretty sight...and I've got big hands
SN Certified Technician
Mar 2, 2015
6,945
5,816
213
Jan 22, 2019
#7
  • Jan 22, 2019
  • #7
Bosch plugs don't like fords....

Change plugs....send it...then check them...
 
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