Ouch Expensive Tune Up

[javacontour]

About 2050 miles ago, I did a tune up on the 03 Protege5. After about 1000 miles, I got a misfire and limped the car home. Seems the plug tube for cylinder 4 was messed up and the gap on the plug got bridged.

I replaced the plug, coil and tube, but the damage was already done. She started using a quart of oil every tank of fuel. I tried a ring soak with MMO, hoping I just stuck a ring. No luck.

No luck on a valve sticking and/or a messed up valve guide or valve seal.

Nope, at 92K miles and just under 2200 miles of personal driving, I'm looking at engine options.

First I'm having a crisis because either I picked a bad car and didn't catch an oil burner, or I blew the tune up. Which option do I hope for.

Finally, I get the car in the shop. Sometimes I can see smoke, sometimes I can't. They think it's valve guides, I simply know whatever the solution will be will be expensive.

They have it about a week, and due to some personal issues with one of the mechanics, it sits there. The next week they remove the head and it's obvious, I broke it. The head looks good, so they look at the scrapes/gouges in cylinder #4. The other three still have their cross hatch.

First plan was to see if they can hone it out, but for various reasons, that's not doable. So finally the whole block comes out and off to the machine shop.

Last night I get my car back, bored out to eliminate the scratches, new pistons, rings, bearings, polished crank, and they went through the head.

I was going to have the water pump and timing belt replaced, so that took some of the sting out of it. My guys are really good and I got the engine R&R'ed, all the machine shop work, the new Mazda water pump, timing belt and even an AC hose that they found a pinhole in for less than what we could find a rebuild.

Oh, and they did new plugs too!

I'm trying to get piston #4 back, so I can leave it on the shelf in the garage as a reminder to double and triple check the spark plug connections.

But my DIY tune up cost me a new engine.

Ouch.

On the plus side, the car has learned it's parameters and runs great. I've driven it about 40-50 miles and am driving it to break it in, with an oil change at 500 and then 2500 miles later until I get to 95K were I'll resume my 5K interval.

If I mange to get the piston, I'll post a picture.

 

[simple_gifts]

I might have to check my reading comprehension. What did you actually screw up?

 

[javacontour]

Cylinder #4 is a type of coil on plug. Ditto for cylinder #2.

Cylinder 1 and 3 each have a traditional plug wire. Cylinder #1 to coil on #4. Cylinder #2 to coil on #3.

There is a tube that goes down from the coil to the plug it sits upon. I must have messed up the tube on #4 as it got fouled and started to misfire.

When I took it out, the boot was buggered up, so shame on me for messing it up.

I suspect not only did the plug misfire, but either the cylinder walls were washed down with fuel and/or the rings stuck and gouged the wall.

Probably both once the plug gap was bridged by deposits.

Bottom line, if I ever change the plugs on this car again, I'll change the tubes and the wires at the same time. And extra $50-60 for wires and tubes is better than thousands for another rebuild.

 

[Cristobal]

What was the cost?

 

[bluestream]

Did you notice the misfire and keep driving? This problem may have nothing to do with your tune up. Many engine misfire for long periods with no issues until they get fixed...

 

[chrome]

Highly unlikely the misfiring caused that sort of damage to the cylinder walls and piston, it seems almost like something dropped through the spark plug hole when you were doing the tune-up.

 

[needsducktape]

This sounds odd to me.

I did A tune up on my Protege (30K) and it was as easy as pie- The coils and plugs "pop" into place making the and if they were out, then the coil would be very obviously lopsided sitting on it.

Did you under tighten the spark plugs, then they burst out of the head?

I am no mechanic but the Protege engine layout was seriously easy.

 

[scurvy]

I still fail to see how the engine misfire/#4 bore gouges had anything to do with your tuneup... my reading comprehension must be off tonight or I'm missing something obvious from your posts.

As I understand it:
2k miles ago you did a tuneup on a 2003 Mazda Protege5.
1k miles ago it started misfiring and you limped it home. You replaced parts (COP unit, sparkplug, tube) external to the block & head. Car started using a quart of oil per tank.

How are those events connected, again? I don't even see correlation, much less causation.

 

[fdcg27]

I don't think you caused this.
You could have had a miss for a long time with no damage.
A miss in a 4 cyl is pretty obvious.
Did you noitce it as you drove the car?
Did you have a CEL?
A continuous miss would certainly set a code.
I don't know what happened to this engine, but I don't think you caused it.
Don't beat yourself up without good reason.

 

[IndyIan]

Doesn't sound right to me either, nothing you did would gouge up a cylinder, even a total misfire.
Maybe you dropped something in by accident, but I doubt it.

 

[steve20]

is this for real? - ?

 

[MarkM66]

Originally Posted By: needsducktape
Did you under tighten the spark plugs, then they burst out of the head?


Bingo!

Misfires don't cause this kinda damage.

 

[bdcardinal]

Originally Posted By: needsducktape
Did you under tighten the spark plugs, then they burst out of the head?


That engine family is known for this, although not on a scale of the Ford modular motors. Ever see the Top Gear where they start in Iraq? Jeremy's Miata launched a couple spark plugs.

 

[javacontour]

Originally Posted By: chrome
Highly unlikely the misfiring caused that sort of damage to the cylinder walls and piston, it seems almost like something dropped through the spark plug hole when you were doing the tune-up.



Probably part of the tube or boot at the end of the tube was in there, unnoticed. When I pulled the old plug, it dropped in. That's my best guess. Some of the rubber boot was missing.

Regardless what did it, it was my carelessness that caused it.

The plugs were all in tight. Something fouled #4 to the point where the gap was fully bridged.

I got the flashing check engine light, still close to home, so I turned around and drove a couple miles back home. Put my code reader on it, and it said mis-fire #4 cylinder. That was probably 500-1000 miles after the tune up. I drove it for another 1000-1500 miles, noticing the oil consumption and made the appointment with my shop.

 

[javacontour]

Originally Posted By: IndyIan
Doesn't sound right to me either, nothing you did would gouge up a cylinder, even a total misfire.
Maybe you dropped something in by accident, but I doubt it.


I thought maybe one of the screws for the variable air intake Mazda uses got loose, so I asked my mechanic to check on that. But nope, not that.

(Mazda had a recall for the 2.0L engine for a while to address this but mine was not impacted.)

But he said the damage was not consistent with foreign object damage because there were no marks on the tops of the pistons, head or valves.

That's why I'm thinking something soft like the rubber and/or plastic of the boot fell in, un-noticed by me. It wouldn't put the same type of dings and scratches as a brass screw, but could still foul the rings so they don't get proper lube.

They closed before I got retrieve the piston from the machine shop yesterday, so I'm hoping to get it on Monday. I picked up the car a 8pm on Thursday night but he didn't get the piston yet.

So perhaps that will tell us more.

 

[demarpaint]

The only way the cylinder could be scored up as you describe is something either fell into it, or possibly a ring broke. I doubt you caused it, just bad luck I think.

 

[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

 

[Craig in Canada]

I don't read this as being caused by anything described in the tune up either. As some have said, maybe a foreign body made entry during the service - maybe not. Not connecting a plug wire properly tight isn't going to bridge a plug or cause cylinder scoring. "Misfire" - sure.

 

[Rix]

This is a possible scenario.
The fuel in the cylinder, that isn't being burnt by the spark plug because of a misfire, washes the cylinder walls of their minute amount of lubricating oil, and you get basically direct metal to metal/ring to cylinder wall contact.
scrapes and gouges in the cylinder wall, damaged rings, and oil that turns black and smells like fuel really fast are the usual result.
It usually doesn't happen overnight, though. It usually takes a while.
At least in the toyota world, can't really say for other makes.
On the other end of this scenario..... There's been alot of times that someone has had a piece of broken spark plug (or a plug's porcelain break during removal) in the cylinder, and it will destroy a cylinder in a hurry. There is USUALLY evidence of it on the cumbustion chamber, though.

 

[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.