Blinking Engine Light AFTER Mechanic Work

I had some repairs done to my Honda Accord Coupe (Black) - gasket valve cover, valve idle adjustment, and intake manifold gasket set. Since the repair, the check engine light started blinking and the engine started to misfire, after I parked it for a couple of days, the engine light went off and it seemed to run fine, until yesterday when it happened again?

And what did the mechanic say when you took it back?


I suspect with removing and installing these old ignition coils a failure has occurred. You may have to pay for one or more ignition coils.

Based on the question, I would say that hasn’t happened yet. Already asking for the solution?

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If the light is blinking do not drive it . Get it towed .

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I took it back after the engine light had turned off the first time and he said, without looking at it, there ‘shouldn’t be an issue since the engine light went off, but keep an eye on it’, and it needs to go off twice to confirm there is an issue, otherwise it’s just a glitch or the system resetting itself. I think now that it’s happened twice, I have an issue?

Yes, there is a problem but for the PCM to store a misfire fault the problem must occur on two consecutive ignition cycles. The first misfire event will record a “pending” fault and cause the check engine light to flash. If the misfire does not occur during the next ignition cycle, the pending fault goes away, erased. This leads to frustration with the mechanic, you had a misfire 3 days ago, but nothing recorded in the computer.

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When I had plugs put in, the wires came apart so had to be replaced. Anytime you you undo some of these it can be a problem. I wouldn’t be happy until the wires and maybe the coils were replaced. A blinking light can ruin a cat which would be much more expensive.

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You have an issue. Take it back, order him to give you the code stored in the computer, and demand that he correct whatever he screwed up.


Whatever the problem is, given what you say, probably not overly serious, meaning not overly expensive to repair. That’s not the same as saying it can be ignored though. If ignored then it may well become very serious and very expensive. Misfire usually mean occasional no spark or no fuel to one or more cylinders. So could be either problem, especially if removing the intake manifold to replace the gasket required removing injectors. still , odds are problem most likely is no spark. Coils, wires. The misfire diagnostic code will say if the problem is limited to a specific cylinder or to all cylinders. That would be an important clue.

The cause of misfires are often diagnosed by swapping stuff (coils, injectors, etc) from one cylinder to another and seeing if the misfire moves to the other cylinder or not.

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If the check engine light is blinking, you have a misfire so bad that it can and will damage your catalytic converter. This is a stop driving condition.

BTW a pending code, which is readable by a code reader does NOT turn on the check engine light. If the pending code is detected in the next drive cycle, then it becomes a regular code and that turns on the check engine light steady. That is a two trip DTC (diagnostic trouble code).

A severe misfire does not set a pending code, it immediately turns on the check engine light blinking. It is a one trip DTC.

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Thank you all for your guidance, it was ignition coils, and I had two replaced.


I have a 2016 CRV, brought it in for routine servicing at 79,000 miles. It has since started running roughly on 3 different highways with the flashing check engine light. It has been towed to the dealer 3 times. They were able to reproduce the problem which gave a cylinder misfire readout. They reset the valves after checking the clearance. The repairs they did were replacing a coolant crossover pipe and a timing cover reseal with gaskets and replace transmission fluid. They are saying, and Honda, that they think it is bad gas. The engine check light would go off when the car was idling, but would resume after driving a few minutes. I never had an issue before the repair work, all done by the dealer. Thank you,

Other than the valve adjustment, your dealer has done nothing to solve the problem. Not much outside of the ignition, fuel and compression would do this. You need to post the exact code or codes they are getting for a better diagnosis. The codes may be on your paperwork.

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As Keith said or if the CEL is not blinking now, you can have the codes read for free (usually) at auto part stores like Autozone or O’Reilly’s. Then post the codes here.

They replaced the coils and we took a 45 minute test drive. I’ll cross my fingers and hold the AAA card in them.
Thank you.

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Bad gas? Did the shop mention any particular theory why they thought this problem might be caused by bad gasoline? Such a thing is possible of course, but seems unlikely unless bad gas is a common thing in your area. Did you purchase gas at a station other than you normally use before this started? One idea, you could frequently top off gas tank with known to be good gasoline; if problem gradually resolves, that would tend to verify the bad gas theory.

If problem continues, you’ll get better results here by posting your problem as a new topic. Click maintenance/repairs upper left, then new topic upper right.

A complete guess is the prior work disturbed the ignition coils and/or spark plugs or the wiring to them.

Let us know if that fixed it. Coils seem like a likely culprit.

So far the car has run fine on short trips and the 45 minute test drive with a mechanic. He had swapped out the coils and he had the computer plugged in the whole drive. Just one minor misfire that we didn’t notice but the computer picked it up.
Thank you

Hi again, its been about a week later, after getting gasket repairs, and ignition coils replaced, now the battery light has come on after accelerating on to the highway? The car starts fine, but there is an unusual humming noise. I took it to auto zone, where I bought a battery less than 2 months ago, thinking that was the issue, however they ran a diagnostic test and it showed the following:

Anti-Lick Brake System

  • 83-13 ECM/PCM Relation Failure
  • 61-1 Control Unit Low Voltage

Any suggestions on what this means and if it’s connected to the previous work I’ve recently had on the car?

That symptom sounds like an alternator or accessory/serpentine belt problem. Could just be incorrect belt tension. Ask your shop to check.

As far as the diagnostic codes, those are not in the normal format we get here, so not sure what they might mean. The normal format starts with the letter P, followed by 4 digits; e.g. P0420, something like that. Those codes may be specific to the manufacturer and would normally require a shop with expertise with that particular manufacturer’s cars, dealership for example. Ask you shop if solving the anti-lock system problems can be deferred. i.e just be aware you don’t have this system working, and the brakes will be more likely to lock-up, so drive more carefully. Many vehicles on the road don’t have anti-lock systems.