OVERKILL
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Did you inspect the plugs you pulled for pieces of porcelain missing? How about the plugs you put in (that were then replaced)?
Ouch Expensive Tune Up
- Thread starter javacontour
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Originally Posted By: javacontour
Originally Posted By: Vikas
Can somebody explain to me as to what actually happened here using logic rather than emotions? Java has been around for a long time and I think he should be able to look at it more rationally.
As far as I can figure out, something inside the cylinder broke and I can not imagine what java did could have caused that to happen. The so called "tube" that keeps on mentioning can NOT enter the cylinder hole because its width is bigger than the threaded cylinder hole. Besides, there is spark plug sitting between the tube and the cylinder.
Are these engine known to have valve problems i.e. mysteriously eating part of the valve train? Some of the Nissans have been known to ingest broken precats through exhaust valves (don't ask me for an explanation!) and scouring the cylinder walls and high oil consumption and eventual demise of the engine. I don't think I had heard of Mazda engines doing similar harakiri.
- Vikas
Facts:
1. The tube was damaged.
2. The engine was using oil, a quart every 200-300 miles.
3. Scoring was found in #4 cylinder.
4. The Mazda variable intake was in tact, no missing fasteners in the butterflies.
My speculation is that something from the tube did fall into the cylinder. Of course it cannot fall in there while the plug is there. But if it breaks off while the plug is still there and is not noticed and the plug is removed, it can fall into the cylinder AFTER the plug is removed.
I got the piston back yesterday and it looks like something did bounce around on the top of the piston. It looks like something was in there. Something small. I can see where the cylinder wall was scored as there is matching scoring above the top ring land on the piston.
I'll try to get some pics later.
I didn't get the rings back. But I'd think the machine shop would have mentioned in the rings broke.
I'd guess part of a plug, but you never know.
Originally Posted By: Vikas
Can somebody explain to me as to what actually happened here using logic rather than emotions? Java has been around for a long time and I think he should be able to look at it more rationally.
As far as I can figure out, something inside the cylinder broke and I can not imagine what java did could have caused that to happen. The so called "tube" that keeps on mentioning can NOT enter the cylinder hole because its width is bigger than the threaded cylinder hole. Besides, there is spark plug sitting between the tube and the cylinder.
Are these engine known to have valve problems i.e. mysteriously eating part of the valve train? Some of the Nissans have been known to ingest broken precats through exhaust valves (don't ask me for an explanation!) and scouring the cylinder walls and high oil consumption and eventual demise of the engine. I don't think I had heard of Mazda engines doing similar harakiri.
- Vikas
Facts:
1. The tube was damaged.
2. The engine was using oil, a quart every 200-300 miles.
3. Scoring was found in #4 cylinder.
4. The Mazda variable intake was in tact, no missing fasteners in the butterflies.
My speculation is that something from the tube did fall into the cylinder. Of course it cannot fall in there while the plug is there. But if it breaks off while the plug is still there and is not noticed and the plug is removed, it can fall into the cylinder AFTER the plug is removed.
I got the piston back yesterday and it looks like something did bounce around on the top of the piston. It looks like something was in there. Something small. I can see where the cylinder wall was scored as there is matching scoring above the top ring land on the piston.
I'll try to get some pics later.
I didn't get the rings back. But I'd think the machine shop would have mentioned in the rings broke.
I'd guess part of a plug, but you never know.
I still have the plugs that came with the car and the plug I re-replaced on cylinder #4. I'll check to see if the platinum "pad" is still on the plug. I don't have the four that went to the shop for the rebuild. But the "originals" and the #4 that was replaced are probably the most interesting.
I think the plugs that were in there were copper plugs as Mazda calls for a 30K replacement interval on the plugs.
It's obvious from the piston that something did get in there. A co-worker best described it as it looks like someone attacked the top of the piston with an ice-pick.
As I said, I'll try to get some pictures up when can borrow oilBabe's digital camera, or use mine.
Probably not tonight as it's date night with oilBabe.
I think the plugs that were in there were copper plugs as Mazda calls for a 30K replacement interval on the plugs.
It's obvious from the piston that something did get in there. A co-worker best described it as it looks like someone attacked the top of the piston with an ice-pick.
As I said, I'll try to get some pictures up when can borrow oilBabe's digital camera, or use mine.
Probably not tonight as it's date night with oilBabe.
I wish I had a picture of the 2uz-fe piston with the valve imbedded almost perfectly dead center and perpendicular to the piston head.
THAT was pretty awesome.
I've had lots of 3vz-e engines apart with evidence of foreign material in the cylinder. LOTS of times it was pieces of porcelain missing from the plug because of head gasket issues and coolant entering a really hot cylinder.
THAT was pretty awesome.
I've had lots of 3vz-e engines apart with evidence of foreign material in the cylinder. LOTS of times it was pieces of porcelain missing from the plug because of head gasket issues and coolant entering a really hot cylinder.
Originally Posted By: needsducktape
This sounds odd to me.
Sounds downright freakish. Actually, it sounds like something hard and relatively big (I'm thinking much bigger and harder than a plug insulator tip) got sucked into cylinder 4... no way in HECK should a simple misfire do that kind of damage to an engine in only 1000 miles. Sheesh, I have no idea how many misfiring Ford, GM, and Chrysler v8s I've seen back in the 70s and 80s that ran that way for months or years, then got fresh plugs or wires and ran like nothing ever happened. And besides- "washdown" wear makes the inside of a cylinder look like a mirror, not gouged and scraped.
This sounds odd to me.
Sounds downright freakish. Actually, it sounds like something hard and relatively big (I'm thinking much bigger and harder than a plug insulator tip) got sucked into cylinder 4... no way in HECK should a simple misfire do that kind of damage to an engine in only 1000 miles. Sheesh, I have no idea how many misfiring Ford, GM, and Chrysler v8s I've seen back in the 70s and 80s that ran that way for months or years, then got fresh plugs or wires and ran like nothing ever happened. And besides- "washdown" wear makes the inside of a cylinder look like a mirror, not gouged and scraped.
I've never met a OHC valve cover that had enough room for anything to get around a spark plug socket. Did you put the wire back in the hole without the plug in? I don't see anyway for something you did to have caused this unless you knocked something in.
I'm thinking that when you removed the old plug to replace there was something near by you couldn't see (hidden by the plug body...) that as you removed the plug the object was simply was able to drop in. I'm wondering if it wasn't a small hard pebble or the like.
Originally Posted By: JoeWGauss
I'm thinking that when you removed the old plug to replace there was something near by you couldn't see (hidden by the plug body...) that as you removed the plug the object was simply was able to drop in. I'm wondering if it wasn't a small hard pebble or the like.
Or a VC nut dropped by another technician
I'm thinking that when you removed the old plug to replace there was something near by you couldn't see (hidden by the plug body...) that as you removed the plug the object was simply was able to drop in. I'm wondering if it wasn't a small hard pebble or the like.
Or a VC nut dropped by another technician
So it fell in and took nearly 1000 miles to cause enough damage that it could be noticed?
The reality-o-meter on this one:
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The reality-o-meter on this one:
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OVERKILL
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Originally Posted By: brianl703
So it fell in and took nearly 1000 miles to cause enough damage that it could be noticed?
The reality-o-meter on this one:
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That's why I was particularly interested in the plugs that the mechanic took out when they rebuilt it. I'm thinking that if the plug broke and a piece dislodged, that it would be on THAT plug, as the failure would have been an immediate result of this.
So it fell in and took nearly 1000 miles to cause enough damage that it could be noticed?
The reality-o-meter on this one:
[\...........]
That's why I was particularly interested in the plugs that the mechanic took out when they rebuilt it. I'm thinking that if the plug broke and a piece dislodged, that it would be on THAT plug, as the failure would have been an immediate result of this.
Originally Posted By: Vikas
What kind of plugs drop their porcelain in the cylinder head? Are they NGK or Denso?
Autolite, mighty, etc.
Usually.
What kind of plugs drop their porcelain in the cylinder head? Are they NGK or Denso?
Autolite, mighty, etc.
Usually.
Well, something got in there as none of the other cylinders were damaged. Nor did this one foul the plug nearly as badly the 2nd 1000 miles.
I still think it was some of the boot/plastic from the tube, it melted and stuck, perhaps causing hot spots on the piston that caused pre-ignition. I did hear pinging, that would be consistent.
Once the piston was damaged, the game was up.
It's all speculation at this point.
Something fell in.
Plug fouled enough in 1000 miles to generate a flashing CEL and totally bridge the plug gap.
Replacement plug not noted as being fouled by mechanic.
If the plastic/rubber turns to a bit of charcoal, it can either bounce around and/or become a pre-ignition source and start to damage the piston by that pre-ignition.
I have some pics of the piston:
http://s960.photobucket.com/albums/ae86/tbright1965/2003_Mazda_Protege_Piston/
You can see some of the rough edges on skirt sides. The top of the piston is not smooth. In fact, it's chewed up a bit on the piston top above the skirts. The same area above the wrist pin is relatively smoother.
It's that damage that makes me think pre-ignition had something to do with what went down.
I still think it was some of the boot/plastic from the tube, it melted and stuck, perhaps causing hot spots on the piston that caused pre-ignition. I did hear pinging, that would be consistent.
Once the piston was damaged, the game was up.
It's all speculation at this point.
Something fell in.
Plug fouled enough in 1000 miles to generate a flashing CEL and totally bridge the plug gap.
Replacement plug not noted as being fouled by mechanic.
If the plastic/rubber turns to a bit of charcoal, it can either bounce around and/or become a pre-ignition source and start to damage the piston by that pre-ignition.
I have some pics of the piston:
http://s960.photobucket.com/albums/ae86/tbright1965/2003_Mazda_Protege_Piston/
You can see some of the rough edges on skirt sides. The top of the piston is not smooth. In fact, it's chewed up a bit on the piston top above the skirts. The same area above the wrist pin is relatively smoother.
It's that damage that makes me think pre-ignition had something to do with what went down.
OVERKILL
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Can you get some better pictures?
I was thinking the same... maybe take them outside during daylight? The flash is way too bright for how close you're holding the piston.
As the other 2 guys said, its hard to tell from those pictures. But it really doesn't look like detonation damage to me. A clearer view of the top ring land and the top circumference of the piston would help. I would expect detonation damage to be more focused on one (or a few) particular locations, rather than all over the whole surface like that. You shouldn't expect to see detonation damage in the center of the piston dish, you'd see it on high points, for example. It looks like physical damage to me. Something sucked down the air intake? Totally unrelated to the plug change? The odd thing is that it looks like something small, and yet it stayed in there a LONG time like it wouldn't fit out the exhaust valve. Very odd.
I agree, I'll try to get better pictures. What you cannot see is there is more severe damage on the edges in the same quadrants as the skirts.
I'll try go get outside in the daylight and snap some photos without the flash.
I'll try go get outside in the daylight and snap some photos without the flash.
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