Speaking of broken spark plugs...

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My ex's 1999 Subaru Legacy (4 cyl, 126K miles) began making some nasty noises in the motor a week ago. She drove it 2 blocks and it's been sitting in the driveway ever since, while she ponders what to do. Except for warranty work, It's been maintained by one very competent mechanic throughout its life. He's hesitant to mess with it because he says that evaluation could require major engine disassembly which could cost so much that no sane owner would want to even go that far just to find out that the car is toast. Car is in otherwise excellent condition.
So, ***if*** we were dealing with a spark plug which was broken due to incorrect length, wouldn't that have happened almost immediately after the plugs were installed? Assuming yes, what else are we left with? Right length, wrong plug (temperature)? Wrong torque? Defective plug? Seems like some things could point to the mechanic, as unlikely as that seems based on his track record. Or, manufacturer.
Any other thoughts on this?
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On Tue, 8 Dec 2009 10:16:08 -0500, "JoeSpareBedroom"

Probably not a plug if it ran ok after the last change as a plug long enough for the piston to slam into it would have done damage on the first complete upstroke.
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On Tue, 08 Dec 2009 10:16:08 -0500, JoeSpareBedroom wrote:

What are the oil and coolant levels like? Any oil in the coolant expansion tank?
All sorts of things can make "nasty noises" - are we talking knocking, scraping, high-pitched squeal, something else?
At the bad end of the scale, valves hitting pistons due to worn timing gear (although I'm not sure if the Legacy's engine is an interference design where that could happen), or a major bearing fault. At the other end of the scale, I had a locking tab break on a cam gear in an engine once which made a heck of a noise, but it was maybe a $1 part and a ten minute fix.

Can you get a second opinion? Maybe tow it to a garage if you have to so someone can listen to it (just keep in mind that you're free to tow it to more than one garage - don't feel obligated to leave it with the first garage you go to)
Lots of mechanics will be able to narrow it down by ear (and experience).

What makes you think it's related to plugs? Was something changed recently that you didn't mention in your post?
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I thought of plugs because it's the only one of many possible causes I've read about in the past day. Misleading, but it's all I had in mind at the moment.
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I would definitely have it diagnosed to find out exactly what the problem is, rather than just guesses. If it does turn out that the engine is shot, an alternative could be a wrecking yard engine. If the car is in otherwise good shape,paid for, and she likes the car, it could make sense to fix it, even if if it does cost $1000 or so. That would be a judgement call on her part. Repairs may cost what 4-6 payments on a replacement car would be. Larry
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Unless one of the sparkplugs was changed just before starting it up that time, that seems unlikely.
You didn't give us very much info about the problem... Was it running badly or just making noise? Can you describe the noise at all? Are you mechanically inclined enough to at least remove the spark plugs and accessory belts and run the starter? That will narrow things way down with a minimum of effort. (A lot of horrible "engine" noises turn out to be failed alternators, water pumps, etc...)
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Mechanically inclined enough, but not enough time, and it's winter here. These things never seem to happen when the weather's decent.
So, I'm just gathering ideas.
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Update: She had a nearby mechanic (not the usual one) take a look at the car. He pulled the plugs and in fact, one WAS broken. That's as far as it went. He said "No way to determine damage without major teardown - $1500 or so." Our usual mechanic says "More like $2500 - not worth it for a car with book value of $3000-ish". The latter guy is probably being cautious and preparing her for worst case scenario.
What a mess.
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On Tue, 8 Dec 2009 11:13:47 -0500, "JoeSpareBedroom"

You could probably get a guaranteed used engine installed for a lot less than a rebuild of that one. Find a junkyard that has a low mileage wreck with rear end damage. Selling and installing the engine is almost pure profit for them. Negotiate!
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snipped-for-privacy@dog.com wrote:

rent or building maintenance, heat, electricity, taxes, tools, equipment, insurance etc?
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wrote:

All those costs exist without doing engine installs. It's gravy for them. The point is that the materials are pretty close to zero cost. It's all labor from employees who are on the clock anyway, and might otherwise have nothing to keep them busy 100% of the time.
Go visit a wrecking yard, and then get back to us with what you discover.
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snipped-for-privacy@dog.com wrote:

And the person running such an operation might be called "former business owner" or even "bankrupt".
I have been to wrecking yards and have never observed employees hanging around waiting for something to do and I am sure someone paid for the buildings, tools supplies, maintenance and all of the other stuff that goes into operating a business and that someone also will pay for the new tools and supplies that are purchased. Add all of that up and apportion it and nothing in a business is "zero cost".
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wrote:

Feel free to remain ignorant, if that's what you prefer.
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FWIW, I had an Isuzu 4 cyl Diesel break the timing belt, and it was a collision motor. Luckily, the valves are straight up and down, rather than at an angle, and all it did was snap 2 or 3 rocker arms, which were aluminum, or some other fairly soft metal. No other damage done Larry
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Lp1331 1p1331 wrote:

Pretty much all Diesels are interference engines as they have compression ratios in the area of 18:1 to 24:1 or higher
nate
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replace "roosters" with "cox" to reply.
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snipped-for-privacy@dog.com wrote:

Delivering an ad hominem attack when you are unable to defend your position just reduces your credibility even more and only digs you into an even deeper hole..
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wrote:

I am perfectly capable of defending my position. Unfortunately, I can't defend it to someone too stupid to understand. Something about trying to teach a pig to sing...
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wrote:

Whoever replaced the plugs last or perhaps the plug maker owes you an engine overhaul.
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Spoke to her a little while ago. She's thinking they may never have been replaced. She's checking through a pile of receipts, while complaining that our mechanic should've told her to do plugs at the recommended interval. This is one instance where one of our mechanic's best selling points may be at fault: While working on our cars, he'll point out stuff that needs to be done in the future so we can plan our budgets. For instance, if he's rotating tires, he'll say "Think 6 months for front brakes, unless you start driving a lot more than usual."
BUT: He leaves it up to the customer to keep an eye on the car's service intervals and request certain things, which I like. If (and this is a big IF) plugs can fall apart due simply to age, who's at fault? The mechanic for never saying "tuneup time", or the customer, for not keeping an eye on the service schedule in the owner's manual?
And why am I in the middle of all this? :-) Don't ask.
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wrote:

It's a little weird with today's cars. Except for spark plugs, there really is nothing to tune up any more. Cars don't have points or carbs. With unleaded gas, spark plugs last at least 50K miles. I've replaced plugs after 50K miles that looked like they could have gone another 50K miles.
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