ignition coil seating when reinserted - experiences?

Despite owning a prior 996 and a 986, I am working on spark plug and spark plug tube replacement for the first time, on my '00 996. An issue (or perhaps no issue at all?) is that I am not feeling confident that the ignition coils are engaging the plugs when I re-insert them. Instead, the rubber seals on the coils presumably combine with air compression inside the tube to push the coils back out a bit when I think I have them fully seated. It takes screwing in the small Allen-head retaining bolts to make them fully seat, even then, I can't physically feel the coils engage the plugs. Does this sound right/OK? Or is there a technique to making them seat better and definitely engage? If I press them in any harder, I feel like I will break the coil housings. I'm afraid that when I get it all buttoned up, I'll have a misfiring engine from some, or even none, of the plugs actually being firmly seated with the coils.

I also have an '00 and I don't remember experiencing that issue with the coils. It's possible that you didn't seat the tubes fully. I used the flat side of a pry bar to seat my tubes. They should kind of click in when fully seated. I couldn't get them all the way in without using some leverage.

If you have screwed in the allen bolts and they are tight, then the boots are on. There is no other choice. The problem I have is the electrical connection. I can never tell if it has fully seated or not. It causes a CEL if not.

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This is what I was thinking - they can't go in any further. But it sounds like you have had a connection problem before with making a good connection, then? Man, I hope I don't... To wyovino: Yeah, feeling that click of engagement is what I am looking for. I can push them as far in as they will go by hand, until the housings are tight against the engine; I messed with them for about an hour. They initially seat fully/deeply, but then rise back out. I considered using something like a pry bar against the plastic housings, but was afraid I might crack them.

I replaced coils and plugs on my 99 a couple weeks ago. You won�t feel the coils �engage� on the spark plugs when seated. And the coils will sit up just slightly until you bolt them down. This was my experience and she fired right up with no issues.

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Ditto.

Are your plugs proberly seated and torqued to spec?

If the coil bolts are tightened down, you are good to go.

its fine. You'd have to try really hard to get a plug boot squashed between the plug tube and the plug. slide them on, give them a good fingertip push, and bolt them on.

If you haven't buttoned it up yet -are you able to remove the tubes easily? There should be some resistance that requires a boat plug or other tool to remove them.If they come out easily with your fingers, they likely aren't fully seated.

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Indeed, thanks; I suspect you would have to have the plugs sitting pretty far proud of fully screwed in to create an issue...in that odd circumstance, though, I bet the plugs would engage in a more detectable way.

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EDIT (misread things): Yes; I used a boat transom plug to pull them. Some were fairly tough to get out, it varied. Sounds like the majority opinion is that I am hopefully in good shape, and am experiencing the typical situation. Once I get some other maintenance items done and fire her back up, will post what happens...thanks all.

Last time I replaced the sparkplugs I had the same feeling, could not "feel" the click of the coil on the sparkplugs.....but it has been 30K miles since and never had a misfire. I will be doing the work in the spring (sparkplugs and oil tubes)...oil tubes are originals, and I have had a "sweat" of oil and grime on the sides of the engine...never a drop of oil in the floor in 8 years...but next time I will change the tubes and clean up the engine sides and shield...this link shows exactly how my engine looks (and how I want it to look): https://www.renntech.org/topic/32519...ark-plug-tube/

When installing coils you will never "feel" them engage the spark plug. They plug will slide into the coil boot and kiss the spring inside it. Below is a generic image of the spring that is inside the boot. Older cars that had spark plug wires were a little different and you would actual feel them clip into place, if the didn't, they fell off later. Today's coil on plug systems are only help in place by the bolts. the spring pressure makes the connection between the actual coil and the spark plug. It is not uncommon when you replace the coils to have them "push back" so to speak. This is either caused by trapped air or a tight boot that has dielectric grease applied and is completely normal. Bolt it in and you are good.

Thanks, all - great information here. Mine slowly began leaking an occasional drop, which would fall onto the exhaust and burn, prompting the effort.

EDIT: all is well after an initial short drive, and still smooth after driving around town for a couple of hours. I must not have given the car long enough to relearn once back together. Thanks all. (Original content: I buttoned everything back up and have a mild to moderate rough running situation around 1500 RPM. It's not severe, but it's noticeable and new. Otherwise, it starts OK, and revs OK above that RPM range. At idle, out of the exhaust you can hear it is missing a little. Need some input. To review, this is my 2000 C2 manual. I replaced the plugs and plug tubes. Also did an oil change while at it. Removed the mufflers to do all of this. Seeing problems of others, I was pretty (but perhaps not enough) retentive about this. I ensured the following: 1) All plugs appeared to have normal gaps (multi-electrode Bosch 7413 plugs). I torqued them all to 22 ft-lbs or slightly more. All had good sealing washers, overall looked OK. 2) All tubes went in pretty easily using the transom tool and lubrication. Nothing leaking so far. 3) I ensured all coils seated well, all Allen bolts were secured, etc. 4) I ensured all connections seated well - beyond hearing a click, I pushed back the boots to directly see them engage. After hearing the rough running, though, I pulled the muffler and rechecked the passenger side, which I did first a few days ago - all OK. Since I did the driver side yesterday and was definitely careful with same, haven't rechecked it yet, but should be OK. 5) All muffler fasteners went back together as normal, looks good there. 6) The thick chassis ground wire on the passenger side is secure. 7) No CEL or codes on my cheap OBD-II reader. Possible dummy moves: 1) As the ignition wires appeared to self-index by length and location, I didn't mark them - so now I am wondering if I have a pair (or more) miswired. 2) I also didn't mark the coils for location, since they are generic as far as I know. So they are back on random cylinders. But perhaps I was an idiot on that. Ideas? Will tackle it again tonight, maybe by pulling and rechecking the driver side.)

Do you have a code reader where you can see if you have a misfire and on which cylinders?

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My concern is that if all plugs are firing, but a couple of cylinders are swapped, I am not sure any code would be thrown. See item #7 above; nothing came up on a basic reader when letting it run for a short while. Been meaning to get a Foxwell or similar, should probably do so just for this. We'll be flying out for Christmas tomorrow. Maybe I can have that inbound while doing the holidays. Man, I wish I had marked the connectors, and that visibility in this engine compartment was better so I could trace them back more easily. The available space to look at things is nothing like my SC or older 911s, but at least better than the newest 911s.

You would never get the car to idle right if you swapped 2 plug wires. That is not it.

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I was inclined to think this, but I assume nothing after some of the crazy stuff I've seen cars do over the years. On the other hand, it is not idling "right" - but starts up and runs. I fear I am going to end up having to pull and test each coil and examine all of the new plugs too...D@mn it, it ran great before this work, but with minor oil leaks...now not leaking, but not running right. Last thing I need right now. Sounds like a Foxwell is in my future.

As above, all is well after (I think) giving the ECU more time to relearn; will post if that changes - thanks all...

If you engine is misfiring, the ECU adaptation will not fix this. It is easy to figure out what coil plug goes where. Just follow the wiring harnessThe first pug on it is the for first cylinder on that bank and so on.