The truck starts fine and when it was idling just started this loud machine gun sound for a few seconds, then stopped, and then happened again. I turned it off, and now…? May or may not be related but the battery was dead yesterday. We jumped it quickly and drove it to let it charge. Had the battery checked and it tested good. The battery is only about 6 months old but it’s been pretty hot here in southern NM so figured that was probably the cause. There was no check engine light.
I did a search here and spark plugs were mentioned for a Ford, but not sure if that holds true for the Honda. Any ideas would be appreciated thank you.
I’m not sure if I can identify with a machine gun-like sound coming from an engine, but just off the top of my head, I would be much more concerned about the level of the oil in the crankcase than I would about the condition of the battery in a situation like this.
So, PLEASE do not start the engine until you have verified that there is sufficient oil in the crankcase. While we are on the topic of oil, what can you tell us about the oil change regimen for this car, in terms of both odometer mileage and elapsed time?
Yes, your Honda does have spark plugs.
When were they last changed?
If one or more plugs were misfiring, the check engine light would be lit-up or it would be flashing, but I thought that we should try to cover all bases here.
@Sue24, after you verify fluid levels, start the truck with a friend. Open the hood. One of you will stand at the front to listen for the sound and identify where it comes from. The other will start the truck when the engine inspector is ready. Let us know where you think the sound is coming from in addition to the information requested above.
The oil is a little low (maybe half-quart) and is due for a change - I’m 75 miles overdue on the change and had been planning on getting it done this weekend. Otherwise I’m good about getting the oil changed regularly. I know there are spark plugs in all engines, I just meant I wasn’t sure if it could be the same thing causing the sound as with the Ford lol. I’m not sure when the plugs were last changed which probably means it’s time to change them
Ok let me get someone - thanks!!
“I’m good about getting the oil changed regularly”
Just how often is the oil changed, both in terms of odometer mileage and in terms of elapsed time?
Cars that accumulate odometer mileage slowly can also accumulate sludge in the engine if the oil isn’t changed at least every 5 or 6 months, and that sludge can lead to stuck valve lifters which could sound somewhat like a machine gun, I suppose.
Last oil change was in February 2016. So, the engine hasn’t made that sound again… I know I wasn’t hallucinating so…?
It’s intermittent. Keep listening for it and note how often it happens and when. Were you turning the ignition when this occurred?
I think that @jtsanders is thinking about the starter solenoid. Good thought Jt, that would be a machine gun like sound. Maybe a faulty ignition switch???
Yosemite
It’s starting and running no problem. But the air conditioner is not cooling. Maybe it was the compressor gasping it’s last breath?
Yes a compressor bearing going bad could make a bad noise. I think you will have to have this one figured out by a competent mechanic. Is the sound gone now?
Besides the good ideas above, gun-shot like sounds can be caused by exhausts leaks, especially exhaust leaks near the engine. Like from a cracked exhaust manifold, or even a loose spark plug. The reason it might go away is the heat from the engine running expands something and closes off the leak. Another possibility is gasoline is getting into the intake manifold and accumulating there for some reason. This can cause an intake manifold backfire sometimes, which can also sound like a gun shot. As the engine is started and run a few minutes it uses up the gasoline and the sound ends.
When I have sounds like this – well, not my own sounds so much but for my car’s … lol … anyway I’ll get a length of old garden hose and use it as sort of stethoscope to narrow down where exactly the sound is coming from.
The sound hasn’t happened again. Took it for an oil change and still no sounds, just no a/c cooling - of course when it’s 100+ degrees
Thank you all so so much for your advice!! Helped me not to panic lol
In my 2007 Acura MDX that is similar in ways the ac relay is known to stick. This will kill the battery when vehicle is off. Also the system cannot shut off the compressor as needed so it makes a large sound as the freon that is over pressure is released make a large noise sometimes with a puff.
Try replacing the relay ($10 part at dealer). You likely will have to top off the freon now since it low due it being over pressurized and the relief valve letting it out.