Piston Slap: Dear Ecoboost Mustang!

Sajeev Mehta
by Sajeev Mehta
piston slap dear ecoboost mustang

Michael writes:

Hi Sajeev,

Back in December, I purchased a new 2016 Ford Mustang 2.3-liter Ecoboost. Awesome car, my first Ecoboost and my first “sports” car. Anyway, the vehicle only has 2,200 miles and I’m still very much breaking it in.

Much to my dismay, last week while driving home through a wooded stretch, I struck a deer in the middle of the road. The deer was already dead, laying across multiple lanes with no way for me to avoid.

After hitting the deer, I continued on while listening for any unusual noises or driving characteristics that may indicate damage. I made it the two miles home without incident, except the Mustang wouldn’t shift into Park. I was able to shut off and secure the vehicle, but then it wouldn’t restart because the computer did not recognize the transmission as being in Park. Shifting (with difficulty) to neutral allowed the vehicle to start, but with the CEL illuminated.

(Amazingly, the car was cosmetically fine. Not a scratch, other than the undercarriage. The deer passed completely under the car)

Fast forward to today, I picked up the vehicle from a repair shop after my insurance company foot the bill (minus deductible) for everything requiring attention — except the repair sheet only mentions a new front engine cover for the undercarriage and a four-wheel alignment.

In driving the vehicle home and it seems fine.

  1. Is this a realistic repair estimate or could there be things missed? I don’t want to deal with transmission or other issues down the road.
  2. Could Ford attempt to void my warranty if I bring the car into the dealer and they notice the repair? The repair was made at my insurance company’s own facility, but with an OEM part as far as I know.
  3. How much of a resale value hit am I looking at when this hits Carfax?

This is a nearly new car that I plan on keeping a very long time. It is in my best interest that I maintain it in top condition. Thanks for your help!

Sajeev answers:

Thank you for the detailed description! You’ll get more from [s]me[/s] us in determining the potentially hidden costs of hitting a dear.

  1. This answer is purely theory, unless you have photos from the insurance adjuster. We gotta know why you had to “shift with difficulty” into neutral and how that issue was fixed. Hopefully it was just a bit of deer carcass that was removed with no damage to the linkage and transmission position sensor.
  2. If this shifter issue was fixed poorly and/or not with all the necessary parts, yes, you could pay again for that repair. Talk to your insurance agent about that. Odds are FoMoCo wouldn’t void the entire warranty, but then again, do remember the “value” us autojournos give to the motoring public.
  3. Since I’m answering months after your query, pull a CarFax now and dispute the hell out of a potentially overzealous damage assessment. You’ll need all the paperwork from the insurance company/claim and maybe the advice of a seasoned claims adjuster or lawyer. Good luck with that.

[Photo: IIHS]

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry … but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.

Join the conversation
4 of 73 comments
  • VoGo VoGo on Jul 19, 2016

    This sounds like a good opportunity for me to voice my support for cougars. By repopulating cougars in the Eastern half of the US, we would reduce the deer population and save human lives lost from car accidents.

    • See 1 previous
    • PrincipalDan PrincipalDan on Jul 19, 2016

      @runs_on_h8raide VoGo, I doubt you would enjoy carrying a handgun with you just to go on a hike due to the repopulating of the cougar (not the kind who buy their claws in a salon.) Anyone with any brains here in NM doesn't venture into the wilderness without firepower for fear of the cougar.

  • Mdkhoutx Mdkhoutx on Jul 20, 2016

    OP here. Thank you all for the replies! Three months later, and about 1600 miles, no additional issues with the vehicle. When the incident occurred, the vehicle certainly was covered with lots of blood, deer guts and fur. And that was just around the exterior, I can only imagine what the undercarriage looked like. The piece of deer gut in the linkage is a very likely theory. According to my insurance company, there is a lifetime (at least as long as I own the car) guarantee on the work they did. So if anything else related ever occurs, believe me I'll be going back after them. Recently had the car in for it's first oil change (at 3500 miles) at the dealer. While I didn't specifically ask them to look for damage or issues, they didn't come back with anything either. All normal. As a side note, I switched the car over to synthetic, due to sludging issues I've heard of with the 2.3 Ecoboost.

  • Alan GM is still dying. The US auto manufacturing sector overall needs to restructure. It is heavily reliant on large protected vehicles with far more protection than the EU has on its vehicles (25% import tariff).Globally GM has lost out in the EU, UK, Australia, etc. GM has shut down in Australia because it is uncompetitive in a global market. Ford still exists in Australia but is reliant on a Thai manufactured pickup, the Ranger which is Australia's second largest selling vehicle.The US needs to look at producing global products, not 'murica only products. Asians and Europeans can do it. America is not unique.
  • Duane Baldinger Ya my cupcake Mailman will love it!
  • Duane Baldinger Where can I send the cash? It's a surprise BDAY present for my cupcake Mailman. D Duane
  • Art Vandelay Pour one out for the Motors Liquidation Corporation
  • Bill Wade Norm, while true I'll leave you with this. My 2023 RAM is running Android 8 released in 2017.My wife's navigation on her GM truck is a 2021 release, I believe the latest. Android Auto seems to update very week or two. Now, which would you rather have? Anybody with a car a couple of years old NEVER sees any updates. Heck, if your TV is a few years old it's dead on updates. At least cell phones are rapidly updated. If your old phone won't update, buy another $200 phone. If your GM vehicle doesn't update do what, buy another $50,000 GM vehicle?