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  • Spark Plug Cylinder HEAVILY Corroded... Pictures Inside.

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 #275985  by SpeedBallDEVIL
 
So I went to change the plugs on my 01 300M for the first time today. I'm the original owner (technically it was my moms car first) but we have never changed the plugs on it. It has 129,000 miles so it was definitely time to put in some new plugs. I got 8/12 torx screws out, hit the remaining four with WD-40 and got them out in an hour after I tapped them once or twice with a hammer.

When I removed the coil packs I found HEAVY amounts of corrosion in the middle cylinder on the passenger side, and some small amounts on the rear cylinder on the drivers side. The coil packs were difficult enough to remove, I can't imagine a loose pack caused the leak. Should I replace the entire coil pack?

Here are a few pictures of the center cylinder...
Image
Image
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Here's the rear drivers side with minor corrosion.
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I have sprayed some WD-40 down in there in order to loosen up the plug. I'm not changing it today though. On Wednesday I'm going to open it back up and spray a little more down there. By next weekend hopefully I will be able to remove that plug. I spoke with my uncle who's a Cadillac Mechanic and this is what he suggested. I'm really just concerned about rust getting into the opening when I remove the plug...

Any suggestions?
User avatar
 #275990  by Bill Putney
 
If you have a source of compressed air, use a small wire brush to break loose what corrosion you can and use the air to blow any loose stuff out (wear safety goggles!). I wouldn't worry about any getting in the cylinder once you remove the plugs if you do that.

One of the problems of leaving spark plugs in way too long like these have been is that they can be hard to break loose. Only work on them with the engine cold - heating the engine up first can cause the aluminum cylinder head threads to be damaged or ruined when you break the plugs loose and remove them. When you apply torque to break them loose, prevent a side force from also being applied so you don't break the spark plug insulators and end up with its pieces in there.

WD-40 is not a good penetrating oil at all. You would have a greater chance of success using a true penetrating oil, like P-B Blaster. There's another brand that people always swear by, but I forget the name - Kroil?
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 #275991  by EasyRider300M
 
have you had an overheating issue with coolant spraying the top of the engine?
User avatar
 #275999  by SpeedBallDEVIL
 
Bill Putney wrote:If you have a source of compressed air, use a small wire brush to break loose what corrosion you can and use the air to blow any loose stuff out (wear safety goggles!). I wouldn't worry about any getting in the cylinder once you remove the plugs if you do that.

One of the problems of leaving spark plugs in way too long like these have been is that they can be hard to break loose. Only work on them with the engine cold - heating the engine up first can cause the aluminum cylinder head threads to be damaged or ruined when you break the plugs loose and remove them. When you apply torque to break them loose, prevent a side force from also being applied so you don't break the spark plug insulators and end up with its pieces in there.

WD-40 is not a good penetrating oil at all. You would have a greater chance of success using a true penetrating oil, like P-B Blaster. There's another brand that people always swear by, but I forget the name - Kroil?
Thanks Bill! I drove out to the local turkey hill this morning which was a 5 min drive there and back. Otherwise the car has not been run all day. I waited 3-4 hours before I even got to the plugs and the 4 I have removed so far came out easily. Some were a little difficult but nothing compared to the screws holding the coil packs in.

I will also run out and grab some P-B Blaster, I'm sure I'll use that for something else later on down the road.

EasyRider300M wrote:have you had an overheating issue with coolant spraying the top of the engine?

I recently (past 6-months) replaced the radiator. On my way to work it overheated and I pulled over and threw some cheap 50/50 mix in there. It took over a full bottle of it. I let it cool down, drove it home with no overheating issues and replaced the radiator that week and threw some of that G05 or something like that in there. No overheating issues since. Maybe your seeing coolant that came out of the little purge whole on the top of the engine when I had to bleed the coolant lines??
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 #276034  by Brando26
 
yikes! should run wicked better once you get them all replaced!
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 #276040  by SpeedBallDEVIL
 
Yeah it was about time they get replaced :)

With changing just four of the six out I can somewhat notice a MPG difference. I won't really be able to tell until I have them in for a week or so. I was getting 21.6 MPG before. I'd say 75% Highway, 25% Back Hilly County Roads

I'm going to hit the two chambers with P-B Blaster Wedneday and try and clean some of the rust off the sides. Its really built up in there, at least on the middle one.

How can I prevent the leak from happening again though? Clean the seals on the coil packs and set them all to 60 ft lbs or w.e. the units are haha.

-Ryan
User avatar
 #276042  by 300maximilien
 
Have you even tried to remove the "rusty tube" plugs yet or are you just assuming that they will be hard to remove?

Also....I would blow out the WD-40 you sprayed in there before putting PB Blaster in. And you don't need much if you do put it in.
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 #276048  by SpeedBallDEVIL
 
I plan on working the rust off first
Hitting both cylinders with compressed air
Then apply PB-Blaster

I'm doing this on wednesday though. Most of the WD-40 should be gone by then anyway though. I already ran the car once and everything went fine. I'm taking extra precautions removing these plugs because I don't want to risk snapping the plug and then having to take the head off to get it out. My uncle has been in the auto mechanic industry for 40+ years and he has seen it happen. So just to be safe, and considering the large amount of rust inside the chamber, I'm going to shoot it with some PB-Blaster first and take care of it next weekend. The second tube I know is fine, there is just spotting of rust halfway down the chamber there, I'll just clean it out on Wednesday, I dont think I'll bother hitting it with the PB-Blaster though.

Is there anyway I can prevent this from happening again though???
 #276050  by isrb710
 
Ryan,

Try some anti-sieze on the bottoms of the coils where they contact the top of the cylinder tube. That should help them seal a little better plus make it easier to get them off next time.

I also put some di-electric grease on the tip of the plug that contacts the coil - again to make it easier to get off next time.

Did you measure the gap on the old plugs? Your picture with old and new plugs side by side really makes the difference stand out!! The old plug almost looks like its gap is double that of the new plug. WOW!!!!

You can probably soak up the WD-40 with some sturdy paper towels or a rag. If the tubes are still damp with oil, that would also cause the paper towels to pick up any rust that was loosened up by the WD-40. When I changed my plugs a month ago, I added a half-inch diameter piece of clear vinyl tubing to the end of my shop-vac and sucked out the dirt/dust as I also shot compressed air down the tube. Compressed air alone didn't get all the crud out. I have an adapter for my 2 1/2 inch shop-vac hose that I think was intended to allow blowing through a 1/2 inside daimeter tube. But I also use it for vacuuming in small areas. A 3/4" tube might be ideal for vacuuming the spark plug holes - it'd be small enough to fit in the holes and big enough to fit around the spark plug. But a 3/4" tube might require the "ultimate" tool - duct tape - to fasten it to the shop vac hose.

Ron
User avatar
 #276059  by Bill Putney
 
isrb710 wrote:...Try some anti-sieze on the bottoms of the coils where they contact the top of the cylinder tube. That should help them seal a little better plus make it easier to get them off next time...
You probably meant to say dielectric grease there, Ron. In any case - that should be dielectric (AKA ignition) grease on the coil boots where they seal to the tops of the tubes, and lightly around the inside of where they seal against the plug insulator.

You should also *sparingly* put anti-seize on the plug threads - keep it away from the electrode end of the threads - start it 1/8 to 1/4" from that end - again, not thick, just a thin coating, enough to just fill, not overfill, the depths of the threads - back from there.

(Edit: Corrected my error about what to use on plug threads.)
User avatar
 #276066  by SpeedBallDEVIL
 
I didn't really find removing the actual plugs themselves to be an issue at all. With that said would it really be necessary to apply anything to the threads? I set them all to the proper torque so I don't think they will be too difficult to remove if needed. Plus the next time these plugs need to be replaced, the car will probably be out of my hands.

The only issues that came up were well obviously the rust, but I also had the rubber sleeve inside the spark plug sprocket come off and get stuck on the spark plug down in the chamber. I only realized when I went to put the coil pack on and it wouldn't fit snugly. I mean, I could have just forced it on, there was enough room where I could have screwed the coil back down rather easily but I'm glad I didn't haha. By the time I finished it was dark out and I had to use a flashlight to find that the rubber insert was still around the plug :)

Otherwise everything was rather easy to perform.

isrb710 wrote:Ryan,

Try some anti-sieze on the bottoms of the coils where they contact the top of the cylinder tube. That should help them seal a little better plus make it easier to get them off next time.

I also put some di-electric grease on the tip of the plug that contacts the coil - again to make it easier to get off next time.

Did you measure the gap on the old plugs? Your picture with old and new plugs side by side really makes the difference stand out!! The old plug almost looks like its gap is double that of the new plug. WOW!!!!

You can probably soak up the WD-40 with some sturdy paper towels or a rag. If the tubes are still damp with oil, that would also cause the paper towels to pick up any rust that was loosened up by the WD-40. When I changed my plugs a month ago, I added a half-inch diameter piece of clear vinyl tubing to the end of my shop-vac and sucked out the dirt/dust as I also shot compressed air down the tube. Compressed air alone didn't get all the crud out. I have an adapter for my 2 1/2 inch shop-vac hose that I think was intended to allow blowing through a 1/2 inside daimeter tube. But I also use it for vacuuming in small areas. A 3/4" tube might be ideal for vacuuming the spark plug holes - it'd be small enough to fit in the holes and big enough to fit around the spark plug. But a 3/4" tube might require the "ultimate" tool - duct tape - to fasten it to the shop vac hose.

Ron
Thank you! I think I have some small clear hose that will work perfect for this! I also have an air compresser and a fitting that will work great to get down in the chamber. I think the biggest difficulty will be getting something down in there to soak up the WD-40 and PB-Blaster when I put that in there.

-Ryan
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 #276074  by Bill Putney
 
speedballdevil wrote:I didn't really find removing the actual plugs themselves to be an issue at all. With that said would it really be necessary to apply anything to the threads? I set them all to the proper torque so I don't think they will be too difficult to remove if needed...
It's just extra insurance against problems getting the plugs out or damaging the soft aluminum threads (also dis-similar metals). I don't know if the factory puts anti-seize on or not. If they did, does that mean that you would have had a bad time getting the plugs out after 100+k miles without anti-seize? Possible.
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 #276124  by SpeedBallDEVIL
 
Maximus wrote:In your case your right it probably wont matter, seems like you change the plugs out every 100,000 miles anyway. :lol:
Every 130,000 miles actually :)

No lol that's really not the case, my Mom was the original owner actually and we never brought it to the local 5 star for any type of service and until I brought it there for the TP WP, was the only time any sort of mechanic suggested replacing the plugs haha. When she had the car she had no issues. I got it around 90-100k and I ended up replacing the starter, headlights (VERY foggy), radiator, Tie Rod bushings, TP, WP, Thermostat, Rotors, Pads, a new Rim, ETC ETC lol. I've been the only one to actually work on this car in the past 10 years really. I've had it about 4 years now and my excuse for the past three years was that I wasn't really that interested in it lol.. It was just a car to me.

I really enjoy working on it and making it my own. I'm also very thankful for all you guys on here that can help me out, especially when things get a little sticky.. You have all been of much help and its very much appreciated. I may be up for Carisle this year as I live about an hour out from there :)

-Ryan
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 #276448  by Arved
 
Bill Putney wrote:
isrb710 wrote: You should also *sparingly* put dielectric grease on the plug threads - keep it away from the electrode end of the threads - start it 1/8 to 1/4" from that end - again, not thick, just a thin coating, enough to just fill, not overfill, the depths of the threads - back from there.
Why dielectric grease, and not anti-seize compound? I've always (well, not always - when I got smart and started to use anti-seize) used anti-seize. Just two cautions:

(1) make sure the anti-seize does not contain graphite. Graphite and aluminum react with each other. The link above is for a one such anti-seize compound. Note the suggested applications: "Spark plug threads installed in aluminum..." This one looks very similar, but contains graphite, so should be kept away from your nice aluminum parts. IMHO, you risk more harm than good using the wrong anti-seize, but the proper anti-seize is definately better than silicone grease (dielectric grease) or installing dry.

(2) watch your torque. There's a difference between the torque applied to a dry thread, and one applied to a lubricated thread, because of the friction in the thread (or lack thereof). If you don't have a good feel for how tight a spark plug should be, use a torque wrench!
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 #276452  by Bill Putney
 
Arved wrote:
Bill Putney wrote:
isrb710 wrote: You should also *sparingly* put dielectric grease on the plug threads - keep it away from the electrode end of the threads - start it 1/8 to 1/4" from that end - again, not thick, just a thin coating, enough to just fill, not overfill, the depths of the threads - back from there.
Why dielectric grease, and not anti-seize compound?...
Your quoting got messed up there. Here's the original dialog:
Bill Putney wrote:
isrb710 wrote:...Try some anti-sieze on the bottoms of the coils where they contact the top of the cylinder tube. That should help them seal a little better plus make it easier to get them off next time...
You probably meant to say dielectric grease there, Ron. In any case - that should be dielectric (AKA ignition) grease on the coil boots where they seal to the tops of the tubes, and lightly around the inside of where they seal against the plug insulator.

You should also *sparingly* put dielectric grease on the plug threads - keep it away from the electrode end of the threads - start it 1/8 to 1/4" from that end - again, not thick, just a thin coating, enough to just fill, not overfill, the depths of the threads - back from there.
I did in fact mean to say put anti-seize on the threads, which is ironic since I started out correcting Ron when he said to use anti-seize on the boot-to-plug seal. Sorry about that. (BTW - I just edited my original post to correct that.)
Arved wrote:...(1) make sure the anti-seize does not contain graphite. Graphite and aluminum react with each other. The link above is for a one such anti-seize compound. Note the suggested applications: "Spark plug threads installed in aluminum..." This one looks very similar, but contains graphite, so should be kept away from your nice aluminum parts. IMHO, you risk more harm than good using the wrong anti-seize, but the proper anti-seize is definately better than silicone grease (dielectric grease) or installing dry.
Good info. While we're on that topic, when do you use aluminum-based anti-seize, and when do you use copper-based? Is either one preferred or is either one *not* good for use with spark plugs in an aluminum head?
Arved wrote:(2) watch your torque. There's a difference between the torque applied to a dry thread, and one applied to a lubricated thread, because of the friction in the thread (or lack thereof). If you don't have a good feel for how tight a spark plug should be, use a torque wrench!
How many of us first read that as "Watch your tongue!"? :)

Do we assume that the specs. given in the FSM are for dry threads or lubed threads? In general, in industry, it's assumed lubed unless otherwise stated - but it may be different in auto books - for instance, for wheel lug nuts, I know that they are supposed to be dry. So which is it for spark plugs? ( I also know that the repeatability of torqueing is very poor - something like 25 or 30% variation typical with the same wrench and fasteners - depending on materials too.)

I looked at the effects of anti-seize on torque a few years ago, and after studying the anit-seize manufacturer's technical sheets, I concluded that anti-seize (possibly intentionally by design?) have friction properties more similar to dry than lubed threads.

There are rules of thumb for dry vs. lubed or wet torque to get the same clamping, but one that I have seen used is if you have the dry torque spec., reduce it by 25% for lubed, or the inverse, if you have the lubed spec., up it by 1/3 if torqueing dry.

If you apply Loctite to a thread before torqueing it, though they don't state it in their literature, Loctite recommends reducing the torque over the dry spec. by 10%.
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 #276467  by Arved
 
Bill Putney wrote:While we're on that topic, when do you use aluminum-based anti-seize, and when do you use copper-based? Is either one preferred or is either one *not* good for use with spark plugs in an aluminum head?.
I don't think it matters directly, as long as it doesn't contain graphite. Copper is used to alloy aluminum, so it shouldn't be a problem. I mostly go for the highest temperature I can find (since we're very close to the combustion process, and you're dissipating heat from the spark plug to the head.

I think 10% is a pretty good figure. If I'm using new spark plugs, I can usually feel the washer getting crushed. When I feel it's completely crushed, I stop. I dunno - I had so much experience changing spark plugs on motorcycles in my youth, I got used to it - even with the crappy spark plug tools included in the motorcycle's tool kit.

Warmest regards!
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 #276472  by Bill Putney
 
Yep - with experience, you develop "calibrated hands".