WARNING! $700.00 to change YOUR spark plugs?!

[@pQlrppl]

Just thought I'd share a recent lesson learned the hard way. A couple of years ago we bought our high school son a 96 Cavalier. It still ran great, but he thought he'd do a little routine maintenaince and change the plugs recently. BIG mistake.

After much research, I have learned that this is a very common problem, so hopefully anyone who had no clue... like us.... can avoid this headache.

These so-called 100,000 mile spark plugs are NOT intended to go 100,000 miles.... or even 30,000 miles.... in a GM car.

Two out of the four plugs broke off.... were seized- welded to the block. None of the tricks worked.... helicoil, etc, and a tear down of the engine was needed to get them out.

Some of the foreign manufacturers were nice enough to put anti-seize coating on their plugs....but not likely in a new American car.

It's all back together now.... heads redone in the machine shop, etc, .... but Grrrrrrrrrrrr. Totally UNnecessary. Expensive lesson.

Anti-seize applied so the next owner will never have to deal with such a stupid repair.

~PQ

 

[The Mountain]

That sounds like the fault of one of two things, neither of which is due to the plugs being high-mileage types:

First: an aluminum head. Almost all small car engines now are all aluminum. Since heat has a greater effect on aluminum than on the steel threads of the plugs, siezed plugs are certainly possible. If you live in a high-corrosion area this can also be a factor, as an aluminum engine block corrodes much more easily than an iron one. Also, it is entirely possible that the 100,000 mile plugs are not the originals. I am not sure, but I think they didn't go to high-mileage plugs from the factory until sometime after 96, which means the previous owner probably installed them himself. Which leads to...

Second: I'll bet dollars to donuts that the previous plugs were torqued far too tight. The usual torque values are measured in inch-pounds. The shade-tree mechanic version is finger-tight plus 1/8 turn with a ratchet. If you broke the plug off at the threads, you had to really wrench on it. Alternatively, they may not have been the right plugs. If they were SAE threads and the head was (all too likely) metric, they would only have gone in once.



As a final knife in the back, let me add that the Cavalier is not the most reliable/well-designed car. The design is a throwback to the bad old '80s, with nothing more than sheetmetal changes since then. Were it me, I'd junk the thing, buy him an older (mid-'70s or earlier) vehicle. Such cars have a higher "cool" quotient, plus are far easier to maintain/learn on, and as a benefit have a higher survival rate in an accident, newfangled saftey thingies such as air(bombs)bags notwithstanding. Heck, an old bug will cost not much more than that head repair you just did, and your son can do everything short of a full engine teardown with fairly minimal handtools and the wonderful John Muir book "How to keep your volkswagen alive for the compleat idiot", which is worth having for the beautiful inkpen artwork if for nothing else.

 

[@pQlrppl]

LP wrote:
That sounds like the fault of one of two things, neither of which is due to the plugs being high-mileage types:

First: an aluminum head. Almost all small car engines now are all aluminum. Since heat has a greater effect on aluminum

PQ replies:
Correct. Aluminum head & heat. BUT GM could avoid the consumer's problems by simply applying anti-seize at the factory like the foreign auto makers do. So even tho the plugs themselves are not at fault...... it much too frequently turns what **should** be very cheap maintenaince into a major headache.

LP wrote:

Also, it is entirely possible that the 100,000 mile plugs are not the originals.

PQ replies:
These were the originals. Of course initially, we had no way of knowing if the previous owner had changed them, but according to brand, etc., they were the factory installed original plugs. Others have had the same problem trying to change the 100k plugs @ 30k.

LP wrote:
I'll bet dollars to donuts that the previous plugs were torqued far too tight. The usual torque values are measured in inch-pounds. The shade-tree mechanic version is finger-tight plus 1/8 turn with a ratchet. If you broke the plug off at the threads, you had to really wrench on it.

PQ replies:
Dunno if GM factory followed torque specs, but SHOULD. The second plug was broken off by the master mechanic who knew what he was dealing with and was being extra careful to avoid a repeat. Unavoidable.

A Google search and auto forums indicate just how common this problem is...... not just w/ the Cavalier of course.

LP wrote:
As a final knife in the back, let me add that the Cavalier is not the most reliable/well-designed car. ...Were it me, I'd junk the thing, buy him an older (mid-'70s or earlier) vehicle.

PQ replies:
True....... and are cheap for a reason..... but even the not-so cheap cars are doing this same plug thing. Just wanted to give everyone a "heads" up LOL.

Yeah.... they sure don't make 'em like they used to. I (as a female even) used to be able to work on my own cars.....

My dad wanted this gal to know when he bought my first car at age 15 that there was more to gas & oil. He made me overhaul the engine ....rings/bearings/the works......

I've had my share of toys AND the old reliables...... wish I had back the 65 Mustang conv that I sold for $100...... or the 67 Firebird..... and many more that are worth a heck of a lot more today. Finally sold the 79 Mercedes 300SD last year after hanging onto it for 23 yrs+ The new owner is still thrilled with it. I sure know what you mean about the oldies...... EZ to work on.... no oxygen sensors..... and all the other dumb crap that you can't get to without dropping the tranny, etc.

The kid is moving onto something bigger..... a good thing..... (this) mom will feel a litttle better about the size..... (mint ..... body wise anyway..... 96 grand Am 3.1) but still.... aluminum. Might be starting all over ..... will find out when warmer weather gets here.

Thanks for your reply
~PQ

 

[OddOne]

I didn't see it mentioned, but the easiest way known to humanity to get a spark plug inextricably wedged in a cylinder head is to change the plug on a hot engine. If you put a plug into a head that's still above ambient, when it cools (and contracts) the threads on both head and plug will become one.

And, this universal constant is independant of the head material. Aluminum AND iron are both subject to the same end result.

My father's shop has had to extricate stuck - AND USUALLY BROKEN - plugs from both aluminum and cast-iron heads. In all but one case the head had to be retapped, or worse, Helicoiled. (FYI: a "Helicoil" is a brand of threaded insert, used to replair damaged threads by tapping out to the next larger size and installing a sleeve with the original thread size inside and the lager outside.)

I've seen cases where antiseize was ineffective thanks to a hot-engine plug install. I've also seen cases where all of the plugs were jammed and had to be Helicoiled. (Either that or spend several hundred MORE to replace the head!)


Worst of all is the cost of the labor for such an operation. It is often literally the same as a head gasket replacement since the head frequently has to be removed. So, that $ you tried to save by doing your own tuneup gets lost and then some in having to fix the after-effects of your tuneup.

oO, who can sling code AND turn a mean wrench...

 

[WFK]

Now I am worried. Have changed plugs on my cars for 35 years, used Auito Moly as anti seize, never a problem. Bought a new Ford Truck 18 months ago. Bitching to the service manager about maintenance cost for this cheap RANGER (02), he estimated service cost for the first 100,000 miles and said:
Spark plugs are platinum plugs and need to be changed at 90 k miles. Cost is $900 for that work.
???
Well, three of the six are inaccessible and THEREFORE Ford used platinum plugs to delay that job as far into the life of the truck as they could. The $900 are essentially labor to make them accessible.

But I have the book, and will dig into the details early. I HOPE that Ford used anti-seize...

 

[clem]

They want you to come back for maintenance, it's the only way they can make the big bucks.
I use to have a 97 GMC Blazer. The ELECTRIC fuel pump is in the top of the gas tank. Part of the fuel pickup hoses and such are made of plastic. Guess what happens when they break?

1. Towed in.
2. Fuel tank drained.
3. Fuel tank REMOVED.
4. Fuel pump replaced.
5. Fuel tank replaced.


How about an access plate in the rear bed area of the Blazed? You know, pull up the carpet. Remove a few screws, take off the plate to access the fuel pump on top of the fuel tank.

You don't think that the enginers and designers didn't think of that?
Some bean counter got ahold of them and slapped that idea out of their minds.

The big guys know exactly what they are doing.

 

[Rusty Shackelford]

Dang........

Glad I own a Jeep.......and work on it myself.

 

[Hamilton Felix]

Hmmm......

Sounds like I'd better get busy resurrecting that M38A1 I just got from Dad. That was what you meant by "Jeep," wasn't it?

We've had fuel pump replaced twice on our 1996 K2500 Suburban. Remove skid plate and 42 gallon gas tank, then replace pump. Expensive job. Mechanic told me once that immersion in fuel helps cool the pump; avoid running the tank really low. I have to agree: An access panel to reach it from above seems like a good idea.

 

[WFK]

Cost of spark plug change. (Outfit: Precision Tune)

Car: 93' Toyota Camry V6 LE.

Maintenance Manual is completely useless:
only instructions are for changing the front THREE, no word about the inaccessible rear ones!

Labor (shop): THREE hours. $224 including platinum plugs, $219 installing supplied plugs. (Air intake manifold must be removed.)

Lesson learned: Japanese Picture Book Manual for that car is worthless!

 

[OddOne]

1. Maintenance on regular intervals is cheaper than repairs brought on by lack of maintenance. ALWAYS. Price out a water pump vs. replacing a cooked engine after the waterpump dies, for one of the more extreme examples.

2. Some vehicles call for platinum spark plugs. They will NOT run right on anything else. Bite the bullet and buy the proper plugs, even if they cost $10+ each. (I know of several vehicles that take $15+ a pop plugs, times eight.)

3. DO NOT, UNDER ANY CIRCUMTANCES BUY BOSCH PLATINUM SPARK PLUGS. They suck, for lack of a better word, and can singlehandedly cause all sorts of performance and driveability problems. These are cheap for a reason - and no, you're not saving yoursel anything in the long run eith 'em.

4. Some cars are just plain not designed to allow for routine maintenance. They're designed to be easily manufactured and that's it. As such, they cost more to maintain. Sorry, blame the car's design team. Aerostars spring to mind - plug replacements run upwards of 3 flat-rate hours on those because the back three are AMAZINGLY hard to reach.

5. Related to #4, unscrupulous techs will shortchange people on plug changes on the more problematic vehicles, usually by performing a 3- or 4-plug tune-up. (Read: replace the easy to replace ones and leave the hard to replace ones alone. You'll still be charged for all six or eight, of course!) If your vehicle falls under this category, ALWAYS ask for ALL your old plugs, and make sure they're all the same brand when you get 'em back unless you know you have a mixture of them. This'll catch the techs that took the shortcut, or deter them from doing so to begin with.

oO

 

[Beast]

I'm glad I have a '74 International Scout II. Very easy to work on. I did find an easy way to change the plugs on my '96 Buick Century though. It has the 3.1 v6. Just remove the "dog bone" or front motor mount and roll the car forward. Chock the wheels and then you can get to the rear spark plugs. When you roll the car forward the whole engine will tilt forward, thus exposing the sparkplugs. Otherwise the rear plugs are near impossible to reach.

 

[WFK]

OddOne,
I think your advice to ask for the old plugs is worth GOLD!

Does your warning regarding Bosch platinum spark plugs extend to ALL their types? I have used the +4 (PLUS4) with success on a 4 cyl Mazda truck for 200,000 miles. No problem.

But during my pricing with Precision Tune (for Toyota) the tech advised against Bosch also. I asked him whether that included the +4, and suddenly he wasn't sure. Looks like he never used the most expensive Boschs.

The reason I ask is that the existing NGKs show electrode erosion after 60k miles on the outside electrode. I wouldn't expect that (and have never seen it) on a Bosch +4 with has four concentric outside electrodes.

 

[don24mac]

$15 bucks apiece (times 4=$60) for the Toyota plugs (Denso) for a 2000 Camry. Installed them myself and ALWAYS in a cold engine. Always use anti-sieze compound, too. Because it's so cheap, don't know why anyone wouldn't use it. I've always done all the maintenance on my vehicles because I don't trust anyone else with my car.

You can really do more than you may be led to believe on vehicle maintenance these days. Even accessing the computer doesn't usually require expensive equipment. Many times, you can retrieve codes by simply turning the key a specific amount of times or some other technique, and then reading the blinking light on the dash. Once you have the codes, it's easy to look in a service manual and see what they mean, or determine what sensor/part might need replacement.

Oh, since it was mentioned in a previous post, Those Auto-Parts store service manuals are useless for the Toyotas. I always use the Toyota Repair Manual, which is the same as the Toyota Service Technicians use. The Manufacturer's Service Manual is more expensive, but worth it if you're doing the work on your car.

 

[OddOne]

OddOne,
I think your advice to ask for the old plugs is worth GOLD!

Does your warning regarding Bosch platinum spark plugs extend to ALL their types? I have used the +4 (PLUS4) with success on a 4 cyl Mazda truck for 200,000 miles. No problem.

But during my pricing with Precision Tune (for Toyota) the tech advised against Bosch also. I asked him whether that included the +4, and suddenly he wasn't sure. Looks like he never used the most expensive Boschs.

The reason I ask is that the existing NGKs show electrode erosion after 60k miles on the outside electrode. I wouldn't expect that (and have never seen it) on a Bosch +4 with has four concentric outside electrodes.

The four-ground Bosch plugs are also inferior to their Denso and NGK counterparts, as Bosch plates their electrodes instead of using a solid platinum electrode. They aren't nearly as bad as the cheapie single-prong ones, but there's still a difference. Sounds like you lucked out and got a good set.

Again, use whatever is closest to the OEM spec for best results - Bosch does not supply ANY of the car makers as far as I know, but both NGK and Nippon Denso do.

oO

 

[Pathfinder]

One more thing to add to the comments is:

Look at your peticular vehicles service manual, find the torque specs for the spark plugs..

Always use anti-sieze, and tighten them to spec, should'nt have any trouble after that.

 

[Snipe Hunter]

Hey Clem

Did you ever think about unbolting the bed from the frame rather than dropping the gas tank to get at the pump. When I was at a service station I saw it being done on a pickup mech said it was easy since you did not have to drop the gas tank.