So I've started experiencing a weird sensation, definitely coming from the engine, that is intermittent and happens randomly with no consistent reproducible conditions.

I'm a Hyundai repair technician and I've consulted with a handful of our senior techs about my issue and they all have no idea.

Here's the problem. I could be idling cold or hot, driving forwards or backwards, slow or fast, for 2 minutes or 2 hours and the issue will still happen. There's no rhyme or reason to it...

When it happens, the engine feels like its stumbling on itself. The sensation only lasts less than a second. Sometimes it'll happen one time in a drive cycle, sometimes it'll happen 20 times in a drive cycle, sometimes it won't happen at all. Last night I was driving on the highway for maybe 5 minutes and it happened repeatedly. Today I was driving around for hours and it didn't happen once. About a week ago I was putting a headlight bulb in and it happened twice idling. It did it at my work in the shop about 2 weeks ago while I was burping my coolant after flushing my heater core.

As you can see its very random. It almost feels like a misfire but there is no check engine light, no codes, no loss of power, no acceleration issues... just this irritating random stumble.

I want to try to fix it before it gets too bad and leaves me stranded...

If anyone here has ever battled this same problem and repaired it, your input would be greatly appreciated Because I'm stumped...

Thanks

Dan

 

Another thing I noticed when I was burping my coolant with the engine idling and the hood open is that you can hear faint click type noise when the engine stumbles. I can't pinpoint the noise either.

And no my A/C compressor is not kicking on. This issue is persistent with and without the compressor cycling on and off. It will do it with the HVAC system turned completely off as well.