9 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHCracked Ignition Coils
Reported or suspected cause
coolant tank was cracked and leaked
Reported cause
No successful repair reported for this finding.
1
Identified cause
0
Suspected cause
0
Reported fixes
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that report identifying a cause
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Reported cause · Original poster
Turned out that the coolant tank was cracked and leaked when the coolant expanded.
Leading evidence: 'coolant tank was cracked and leaked' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'coolant tank was cracked and leaked' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Check cracks in the coolant tank or loose cover' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
I used a soldering iron to melt over the cracks (its filled nylon) then put some high quality RTV over the crack repair.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
I'll get burned for this (ducks) but when I did my mufflers some of my coils were cracked, so I repaired them.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
I had a cracked coolant expansion tank (second time it did this) and it leaked down on the coil packs and I got misfires, once I replaced the coil pack for the left rear cylinder, it went away, I replaced all of them after that.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
I had a cracked coolant expansion tank (second time it did this) and it leaked down on the coil packs and I got misfires, once I replaced the coil pack for the left rear cylinder, it went away, I replaced all of them after that.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
I had a cracked coolant expansion tank (second time it did this) and it leaked down on the coil packs and I got misfires, once I replaced the coil pack for the left rear cylinder, it went away, I replaced all of them after that.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
I had a cracked coolant expansion tank (second time it did this) and it leaked down on the coil packs and I got misfires, once I replaced the coil pack for the left rear cylinder, it went away, I replaced all of them after that.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
I'm with Chris, I don't know the technical hazard, but this spring after sitting in the relatively cool garage for almost two weeks during massive rain falls I finally got a chance(excuse) to run an errand in the now hot weather.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
9 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261026T212127Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
In a previous post I wrote about a coolant spill after spirited driving. Many responded to check for cracks in the coolant tank or loose cover. Turned out that the coolant tank was cracked and leaked when the coolant expanded. I topped off the tank with distilled water, and was able to drive to the shop for repairs without any danger of overheating. After the tank was replaced, my tech said that several ignition coils were cracked, and this could produce misfires especially if damp/wet. He suggested replacing all six. 51,000 miles and almost 15 years old!
What should I know about cracked ignition coils and misfiring when damp? Is this an emergency (I think not)? If there are misfires is there a risk of damage to the cylinder, valves or pistons? Your esteemed recommendation, please! /X3
I'll get burned for this (ducks) but when I did my mufflers some of my coils were cracked, so I repaired them. I used a soldering iron to melt over the cracks (its filled nylon) then put some high quality RTV over the crack repair.
My car runs great, as far as I know the cracks don't cause any actual failure themselves, all they do is weaken the high voltage isolation, which then if wet fails and allow arcing and misfire. With the cracks filled in and insulated all should be good.
I'm with Chris, I don't know the technical hazard, but this spring after sitting in the relatively cool garage for almost two weeks during massive rain falls I finally got a chance(excuse) to run an errand in the now hot weather. I went about three blocks and got the misfire code for a single cylinder. Took it back home. I did nothing other than confirm the cylinder misfiring. That has been two months ago and still running good. I plan to renew plugs, coils and injectors this winter but for now...I guess I'm livin' on the edge!
The short answer is No, you don't have to change them if you're not having issues with them. When it comes time to replace the plugs, do the coils at the same time - shared labor, parts are relatively inexpensive.
I'm in the process of replacing my plugs and coils after getting a P0301 code (Cylinder 1 misfire). As far as I know, the coils are original (MY 2000, ~70k miles). My plugs still have another 17k miles on them but if you've ever done the replacement yourself, you'll understand why I'm doing them with the coils.
Not an emergency unless you have active faults for misfires. I would put it on the list though. You dont want to be out on a road trip and have it start misfiring in the middle of nowhere. You're due for spark plugs at 60,000 miles, that would be a good time to do the coils.
I had a cracked coolant expansion tank (second time it did this) and it leaked down on the coil packs and I got misfires, once I replaced the coil pack for the left rear cylinder, it went away, I replaced all of them after that.
I just went thru this. It wasn't anything sudden, but I noticed the car was running rougher and rougher. Finally the CEL came on, I stopped at the Autozone and it came back with a P0301 code. I drove it a few more days(it was scheduled to go in to the shop anyway) and on the day I brought it in I thought it was going to die. Extremely rough, vibrations all over, etc.... They replaced all the coils and my O2 sensor and now everything is as it should be again.
My 02 C4Sjust got diagnosed with cracked coils. I took it in because the engine actually died while in motion. Turns out several coils didn’t even register anymore. So I’ll be replacing the packs as soon as they get in.
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