2016 Trax driving intermittent miss under light acceleration, also at idle

JP

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#1
Make
Chevy
Model
Trax
Year
2016
Miles
39K
Engine
standard
Still under powertrain warranty, 39K miles. No previous issues.

Started the other day, intermittent "Chug" under light acceleration. Just gives one "bump", not a chug-chug-chug like a slipping/grabbing clutch with a manual trans.

Usually around 35+ mph, seems like either in 5th or 6th gear...has done it in 4th. Also has done it at idle in drive. Didn't happen at idle in park, but I haven't let it idle in park for more than a couple minutes yet.

Does have a recall for the Evap. or EGR valve, can't recall which. This seems like a tranny-shifting-slippy clutch thingy going on rather than an engine stumble. Tach doesn't move when it happens (I know this doesn't mean very much ;) ).

Planning on taking it to the dealer since it's still under the powertrain warranty. Any ideas of what it might be?
 

JP

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#2
Taking it in today for the recall. We'll see if that's the problemo.

Update: Didn't find the problem but did replace the front control arms under a different recall. Interesting...my wife took in the car and was talking with the write-up guy regarding the original problem. Says if a code was set, they'd repair it. If no code set, no repair. Other guy says to him, "Are we telling people about that?"

Makes me wonder if there's some warranty shenanigans going on. Maybe just an innocent comment? In any case, not fixed yet.

Engine glitch or transmission glitch? Any guesses? Seems to have happened only in cold weather.
 
Last edited:

JP

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No code set...dealer wouldn't fix anything under warranty.

So...seems to happen when it's wet out...not sure if it happens when cold and dry.

Any input?
 

JP

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#5
I was thinking that too, but it occurs if the defrost is on or off. Compressor clutch is very loud BTW. I chalked that up to cheap engineering and lack of sound deadening.
 

big al

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#6
My guess is a coil or bad plug. Fought an issue similar to this. Sure could feel it when driving and sometimes listening to it. No check engine lights or any stored or pending codes. After much frustration and teaching myself a different langauge i found it was a faulty coil - replaced coil and plug for that cylinder and was perfect after. Guess the coil had a very fast intermittant short that didnt last long enuff to set code. This was on a Ford not Chevy but same symptoms. Mileage was 23,000 and dealer didnt figure it out either.
 
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#13
Water in gas has been a problem around here, way too much rain, and even with gas stations that was not a problem is a problem today. Law says tanks must be buried underground.

Same problems with aircraft, but did get permission to put those above ground, but talk about no smoking signs, guess its okay to use an acetylene torch.

Nothing beats a pressure system tester, had a hose where you can hot wire the fuel pump and put gas in a clear container, will see water settle to the bottom. So quick, so easy. Say a couple of cans of Heet work, not a chemist, have no idea.

Son filled up in Milwaukee sure got a hot of water, had a 300 mile trip home, CEL kept on flashing, with stopped at several convenient store gas stations, sure could buy tons of beer, but no Heet. Through some miracle made it home. It cleared up up after getting a fresh tank of fuel.

For every new vehicle I purchased going to back to 1962, never had one where the spark plugs were gaped correctly. GM was pushing 0.060" know the engineer that pushed that, he was a complete idiot. You find in real high speed engines gaps as low as 0.012" motorcycle engineers are noted to have more brains the car engineers. Been gaping mine at 25 mils for years, that really prevents misfire.

Joules are the unit of measurement for a spark product of volts and amps. When Volts goes way up with a larger gap, amps go way down that results in a weak spark and even with a little moisture, a misfire.

Aviation plugs for your information are fixed gaped, not adjustable.
 
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#15
Is this called an event?

Called progress, Model A Ford and other 30's vehicles had a clear bulb filter where you could see the water at the bottom of it with a drain to get rid of it. This new stuff is all sealed and can't see anything. This is progress.