Bad ignition coil reddit. It started having problems almost immediately after the 7 day return period was up (actually, the first problem was right when they had towed my car to my house, the key fob had a dead battery and none of the buttons worked and that was the only way of starting up the car since its keyless), starting with the ignition coils which somehow just Well what you're experiencing could be a symptom of a bad coil (or coil pack), but it could also be one of a number of other problems. Nov 11, 2025 · In this guide, we cover the symptoms of a bad ignition coil and discuss how this part functions. CAMRY** What's the tell tell signs of a bad coil pack or sparks plugs? It would be in relation to a Toyota carry 4 door car. Generally a good quality coil is cheap. So it's likely that the single ignition coil is bad. First - a few questions. If you have an OBD-II diagnostic scanner, you may see a P0351 ignition code. I swapped out the ignition coil with an adjacent coil and misfire followed to the new cylinder indicating a likely bad coil. This means that you may have a coil that goes bad over time. . New comments cannot be posted and votes cannot be cast. 3, round coils. Someone else can chime in if the ignition coil driver is embedded in the PCM or not. If electrical resistance in the secondary ignition circuit is too high the coil must generate a higher voltage to fire the plug. Finally, you get some answers to questions you may be afraid to ask. Jan 8, 2016 · Usually a faulty ignition coil will produce a few symptoms that alert the driver of a potential issue. This guide covers the symptoms of a bad ignition coil, common causes, and step-by-step diagnostics to fix it yourself—potentially saving you $200-$800 on unnecessary shop visits. With most modern vehicles, a faulty ignition coil is enough to turn on the Check Engine Light. He said it feels like one of my ignition coils isn’t too happy. Nov 17, 2025 · A bad ignition coil can cause a wide range of problems, from hard starting and engine misfires to loss of power and poor fuel economy — and because its symptoms often overlap with spark plug or fuel injector issues, it’s important to understand exactly how to identify it. Ignition coil bad? So I just got back from the mechanic after an ongoing problem with my car. A misfiring engine results in a jerking or sputtering feel when you are moving at normal speeds. If a spark plug is not getting the right voltage to create a spark, you may experience a hard start. What do bad spark plugs and bad ignition coils physically look like? I tried searching online but all that kept popping up was symptoms of bad plugs and coils, I already know I have a bad plug and coil but I wanted to know what physical characteristics they had when they are bad. Question is, can I drive short distances to groceries and stuff before they arrive? Simple way to test ignition coils? '02 Tahoe, 5. Ignition coils can either fail completely or fail intermittently. Just wondering if I'm missing on anything like additional gas mileage by not just replacing them all. I had then replaced with my spark plugs not long ago but I bought the parts from autozone in a pinch because my car broke down and I needed it for work. 5 hours means a shop rate of around $114 - $115 an hour. Mechanic diagnosed that it needs new spark plugs and a coil. The labor time to replace 4 coils is like 1 hour, maybe 1. Worsening Gas Mileage. First (from the guidelines on the sidebar), what year/make/model? Coil packs, replace all or just the bad one? So I've replaced only one in my car which takes 6 coils. Replace ignition coils as needed or all at once? My 2008 scion tC with 115k miles engine is misfiring. Archived post. Hard Starts. Do they usually just either work, until they don't or do they degrade in effectiveness over time? (1) Yes, a bad spark plug, incorrect type of spark plug, or a wide spark plug gap can cause a coil to fail. I swapped the ignition coils on cylinder 1 and cylinder 4, and then cylinder 4 started misfiring. Get an oem or high quality coil only fix the one that is bad. Jan 8, 2026 · A faulty ignition coil can spell trouble for your car. Plus probably 2 hours diagnostic? Lets take worst case: $1200 - (Parts 200$ x4 = $800) = 400$ for labor & tax 400$ Labor & Diagnostic over 3. Misfiring Engine. Engine misfires, rough idle, and loss of power One of the most common symptoms associated with a faulty ignition coil is engine performance issues. Sep 4, 2024 · Make sure your battery is fully charged and in good condition, and try again with the Hitachi coils; if that doesn't work, replace the Hitachi coils with the coils you removed and try again. I have a lot of come backs from installing aftermarket coils. But when I turned the car engine on and proceeded to pull each ignition coil one at a time, every one the coils including what I thought was a bad coil caused the engine to respond. After changing plugs and wires I'm still feeling a small misfire at idle. Is there a simple way to test my coils, preferably without removing them? I'm guessing a DMM can't do it. 1. We will also show you the location and explain how to test the coils. 4 banger. I've ordered 4 Bosch ignition coils but it'll take another 3 days to arrive. Illuminated Check Engine Light. Pull the plug while you are there as well make sure it’s good. How likely is it that the other coils will malfunction within a year or so (planning for a new car after that)? We would like to show you a description here but the site won’t allow us. Low fuel pressure / inadequate fuel flow, bad spark plugs/wires/etc, or something else altogether. 5 hours. If an ignition coil is not working properly, your engine will likely misfire. To run, your vehicle's engine needs a spark at the right time. Accordingly, even if your vehicle seems to be performing normally, you should watch for worsening gas mileage. Here are 8 signs of a bad ignition coil along with its average replacement cost. polxcju cgk lksfwp zchk jynszf cfm dwidoup oqgpdapd gznwih mnvg