Piston Slap: Putting the Brakes on Auto Start/Stop? (PART II)

The feedback from last week's Piston Slap was clear: Not only did I get it wrong, but many folks already knew the right answer. The solution for disabling a modern car's auto stop/start is so commonplace from the correct Google search that the answer was right under my nose.

So yes, by all means, look for an "auto start/stop eliminator" designed to be plug-and-play with your vehicle. Just be mindful that installing one could void your warranty, and be aware that you are defeating an EPA-mandated device. (See the video above for other relevant pitfalls.)

Maybe you can get away with it, or maybe not: That answer is beyond the scope of our discussion. Instead, have a look at some comments that came my way after last week's Piston Slap-you might learn just as much as I did!

Creep Up to the Line?

Jonathan Ferrey/Getty Images

Geoffrey: One "hack" we found on our Escape (not sure on other models) is to not hold the brake, but instead inch forward a couple times. That should keep it disabled.

Stay Cool

Chevrolet

Richard: I have a 2023 Traverse High Country. I turn on the A/C set at any temperature. The car has never gone into Start/Stop mode.

Regarding Dealership Conversations …

Scene from the movie Used Cars.IMCDb.org | Columbia Pictures

Brian: I heard you mention calling up the representatives at Ford, Chevy, or Chrysler, and asking them to be able to disable this feature? I mean, as a mechanic for the past 20 years it sounds like a great idea, but has anybody ever actually been able to do that?

Me: I should have been clearer when making that suggestion. I've received straight-up good information from car dealerships about questionable mods like auto start/stop elimination. Yes, but there's always a trick to it.

Your average service advisor (the first person you often meet) isn't likely to help. But if you ask nicely for the Service Director (or Fixed Ops Director) you can sometimes get valid recommendations outside of what their corporate overlords recommend. These people have seen it all, and sometimes they are willing to help. Their advice becomes much more affordable when they know the vehicle in question is outside of the warranty period. (And sometimes they go out of their way for a nice person who just bought their brand of vehicle as a used car, too.)

I have been this lucky in a general sense, and that's because they will include CYA statements to ensure such recommendations don't come back to haunt them. It is worth a shot, even if it is one helluva long shot. But not in this case, because everyone knows to look for eliminator kits, except for yours truly.

A Problem in the Big Picture?

Nicolas Economou/NurPhoto/Getty Images

Dean: I have a follow-up question for you. If you use the auto-stop feature on your car, and your car auto stops and starts several times while you are running a few shopping errands (say maybe 12 times in one trip) as opposed to only two times w/o the feature, what effect does this effort have on the life of your vehicle's starter?

Me: The effect of multiple stop-starts is supposed to be negligible, considering the quality of modern engine oils and the latest starter designs. But the odds of them being perfectly reliable after 10+ years of service has yet to be determined. (And it probably never will be analyzed, to be honest.)

There are plenty of stories on the internet of out-of-warranty vehicles needing expensive repairs when auto stop-start fails. So disabling it with a quality defeat device could be a good idea after the warranty expires. (The odds of you running afoul of the EPA are also quite low, especially if your state doesn't have annual vehicle inspections)

Escaping Engine Damage?

Ford

Jason: I have a '17 Escape with the 1.5-liter EcoBoost engine that has start/stop which can be turned off. Most times (if not all the time) I leave my system off. The reason for that is that I have always heard that most engine wear (of a properly maintained engine) occurs on startup.

If this is true, how does start/stop not kill your engine with increased wear? Does the oil pump continue to run despite the engine being off? I assume something has to happen to at least, protect the turbo bearings. I appreciate your time!

Me: Much like my previous statement, engine wear should be negligible for at least three reasons:

• Auto stop/start is usually (only?) activated when the engine is at operating temperature, and there is generally very little wear outside of cold starting.
• Modern GF-6A oils are light years ahead of stuff we used just a few years ago.
• Even engine bearings have evolved to work with auto stop/start.

As always, your mileage may vary. Especially if you have a pre-owned vehicle with zero service history.

About Hood Latches

MOPAR

Don: I have disabled the start/stop feature on my 2018 Jeep Cherokee Latitude by removing the wire harness connector to the hood latch assembly. This will bring up a service message on the instrument display every time you start the vehicle but at least it disables the function.

Brendon: I have a 2018 Chevy Traverse. When I first got it there was nothing available to disable it. The Traverse doesn't even have a button to turn it off. Recently I found a plug-in harness on Amazon. I believe it tells the computer the hood is open because it plugs into the hood latch sensor. No more start stop, no check engine lights or anything, and it was only $15.

Low Voltage Detection?

Jeep

Philip: In my experience with a 2016 Cherokee, they have a module on the negative battery lead to detect low voltage and disable stop/start. If you disconnect this, the function is disabled. You do get a very small warning light on the dash, but no more stopping.

I have used this for three years now without a problem. Living in a warm tropical environment I don't like the loss of my a/c whilst stopped. I hope this information helps, not sure what other models have the same system.

Too Bad It Won't Default to "Off"

Wikimedia | Bindydad123

Mark: I know many complain about the auto-stop features, and I am glad you can at least turn it off. I wish the automakers wired it so it would be off all the time, enabling it at your own will with the push of a button.

SM: Ain't that the truth? Too bad the EPA wouldn't care for that.

Marino: Your article last week was 100% incorrect. Your statement should have been auto start/stop is required by EPA. Deactivating is like removing the catalytic converter. Completely illegal.

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