First spark plug check (~2000 miles) [big pic]
#1
Instructor
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Well, the weather is nice and so I took the chance to pull the plugs to give them a looksee after around 2000 miles, maybe less.
It's been over a year of driving since the engine was rebuilt and I figured I'd give it a look.
![](http://www.theexitwound.com/944/plugs1to4.jpg)
The gaps look neat and clean, but there is something of concern on cylinders 2 and 4 that I'd like some input on.
![](http://www.theexitwound.com/944/plugs2and4.jpg)
There seems to be either a layer of decay that's peeling away, or it's a layer of gunk caked on. I couldn't get it off though by scraping. What does it look like to you?
The car was run with presumably the original Oxygen Sensor for the first 500 miles or so, then it was changed with a new Bosch universal.
It's been over a year of driving since the engine was rebuilt and I figured I'd give it a look.
![](http://www.theexitwound.com/944/plugs1to4.jpg)
The gaps look neat and clean, but there is something of concern on cylinders 2 and 4 that I'd like some input on.
![](http://www.theexitwound.com/944/plugs2and4.jpg)
There seems to be either a layer of decay that's peeling away, or it's a layer of gunk caked on. I couldn't get it off though by scraping. What does it look like to you?
The car was run with presumably the original Oxygen Sensor for the first 500 miles or so, then it was changed with a new Bosch universal.
#4
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Well, I have to be honest and say that we rebuilt everything except the piston rings. Due to time constraints at the time, and other issues which I won't go into, they were not changed. They may be the original rings (130,000 miles). We did compression tests on all 4 cylinders and they all showed "green" (sorry for not remembering the exact results, but they were all fairly decent, which is why we skipped over the rings).
#5
Three Wheelin'
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So what did the rebuild entail as related to oil getting int he cylinders? Did you rebuild the head, including valve guide seals?
If you aren't having any running issues, I'd put new plugs in, and run them for a few thousand to see if they look like these. If they do, you know what cylinders you have an issue on, but there might not be much that you really need to do about it.
If you aren't having any running issues, I'd put new plugs in, and run them for a few thousand to see if they look like these. If they do, you know what cylinders you have an issue on, but there might not be much that you really need to do about it.
#6
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Yeah, the head was sent off, resurfaced with a complete valve job done on them.
So it does look like oil deposits then? I don't have much experience in diagnosing plugs yet.
So it does look like oil deposits then? I don't have much experience in diagnosing plugs yet.
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#8
Rainman
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might be oil from replacing the valves in the guides..although at 130k a decent amount of oil will be coming through the rings anyways.
+1 on changing the plugs and checking them in a month or so.
+1 on changing the plugs and checking them in a month or so.
#9
Three Wheelin'
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Really? What kind of maintenance have been done on the motors you deal with? I've got almost 180k and my plugs don't look like that. And 205k on a Ford 4.6 and they don't look like that.
#10
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Some folks just talk out of their ***, and from the posts I've seen V2 make, on ignore he goes.
#11
Three Wheelin'
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V2 seems to feel that he needs to respond to every post, whether he can actually contribute or not. Which is a shame, because he actually does contribute with correct information sometimes. But I've seen a whole lot of sketchy guesses coming out of him as well.
#12
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It's confusing because the electrodes look perfect where the action occurs. It's not until deep down the base does any corosion/corruption occur, which I can't figure out.
#13
Three Wheelin'
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"Where the action occurs" is where that stuff gets burned off more efficiently. You'd need a really poorly running motor (probably missing on that cylinder, and blowing a whole lot more oil into it) to get the entire electrode covered in that gunk.
#14
Rainman
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has your engine ever been apart? a motor that has been apart will have a little bit of oil leakage as things get settled in. thats why you change the oil on a rebuilt motor quicker than you normally would the first time.
#15
Three Wheelin'
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![](http://forums.rennlist.com/upload/dj_headoff.jpg)
And, yes, you change the oil quicker. Because you can't account for filings from machines parts and various other contamination.
So lets cover your post in parts:
Possibly. But suspicious because its only on 2.
WTF? No. This is what I'm talking about. Unless you're on the 45,0000 miles whether it needs it or not oil change plan.