A Car noob here. I have a Toyota Rav4 model 2014 and I always go to Toyota's service center for my regular maintenance. I know they need to make money so I expect to be ripped off every time I visit for what should be just a 90$ oil change, but they always come up with something that needs replacing, lubricating, etc.

I usually don't argue because I know about cars as much as I know about nuclear physics.

However, today was a little bit strange. I was waiting for the service to be done on my car at Starbucks and I got a call from my service center. No surprise! I know they have found something that needs to be changed.

This time they said there is some kind of a rodent that was in my engine, and they need to do an Engine "Shampoo". I asked how much is that "Shampooing" service and they said 60$. (In my mind I said 60$ is not bad, there must be something else). So I told her yes, 60$ is fine, use as much Shampoo as you like.

Then she said oh but there is a problem (Here we go), there are two wires that are chewed a little bit but they are still intact and we cannot do the shampooing before we replace those two wires. I said fine, how much to replace the two wires, then, BAM 500$+Tax.

I told her you know what, leave it as it is right know until I figure out what I need to do, this is when she basically went back to the same old script which is so and so needs lubricating (50$) and the car needs some EFI & Throttle service for 200$ which I never argue about because that could be legitimate.

So right know, I am going to do all the other stuff, but I am not sure about the Shampooing and the wire replacement thing. I don't want to ignore it if it was a serious problem, but from the way she sounded it looks trivial to me especially for 500$.

When I went home, I opened the hood, and first thing I noticed is that there weren't any rodent droppings that I can see. So I took pictures of the wires and applied some peppermint oil randomly which is something I found online that keeps rodents away.

However, I really didn't know what to take pictures off so I just took bunch of them plus a video of all the wires hooked to the engine. All the pictures are shared at the following link:


The recommendation from the service center are (I am just going to do the last two for now):

  • Repair Two Wires (Coil Pack 2 & 3) - Chewed $500+Tax (4H)
  • Plus Engine Shampoo $59.95+TAX
  • perform EFI & Throttle Body Service 199.90+TAX
  • Lubricate Propeller Shaft blots 39.05+TAX

Could anyone please help me in verifying if "Coil Pack 2 & 3" really need replacing?


  • Dealerships are only one option, take your car to a reputable independent mechanic for a second opinion.
    – GdD
    Commented Sep 24, 2021 at 7:45
  • Honestly this sounds like the dealer is feeding you a line of BS. There's nothing in the photos you provided that looks like a rodent chewed on it. Rodents don't wander by and make a single small nick in the insulation, they go to town and cause massive destruction. All I see is what looks like a slight nick from a tool.
    – barbecue
    Commented Sep 24, 2021 at 21:57
  • 1
    This is what rodent damage to wiring looks like.
    – barbecue
    Commented Sep 24, 2021 at 22:04

2 Answers 2


The shampooing is to remove the rodents scents: Chances are that if another rodent of the same species comes along and smells the former one he will go into "attack male concurrent" mode, resulting in more chewed wires and an destroyed engine room. Ask me how I know. Therefor an engine wash isn't the worst choice. YMMV.

The peppermint oil won't last. People here try a lot of things and they never work (dog hairs, toilet deodorants, etc.). What seems to work are electric shock devices.

The replacement of the wires is a bit complicated: A benevolent explanation would be that perhaps the dealership is required to never repair an engine wiring harness, but replace it. That could explain the high cost. A malevolent explanation would be that they found a small nick in the insulation and immediately wanted to sell you something expensive.

An honest independent mechanic would fix that for a 2 digit amount, or even do it for free as long as he can do other profitable work on your car. For a 2014 make I wouldn't go to the dealership anymore, but I don't know about the quality of the independent mechanics at your location.

What makes me wonder is the regular EFI & Throttle service. We have mostly diesels around, so my knowledge is limited, but I never heard that an engine regularly needs such treatment. Perhaps that varies locally. An separate question about this, on this site, might reveal more


The service center state coil pack 2 & 3 so it should/would be the two middle ones that need attention.

If you look at image 11 (20210923_203515.jpg) and 12 (20210923_203520.jpg) of 50 (see below).

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enter image description here

Unable to get a clear view of 11 as it seems to be from the side/underneath. Inspect that one more. Possibly post a photo of it whilst unclipped, here is a video of how to unclip them (https://www.youtube.com/watch?v=p_pmMHvt10c). It just looks like the plastic has been bitten/slightly cut from the current angle, doesn't look like any wires have been slit.

Would this warrant a replacement? If the wires are exposed and none have been slit, I would say it does not warrant a replacement. If a wire or wires have been slightly slit and my engine isn't idling any different/not having any issues with the way it drives then no. I am assuming you have been driving it like normal without issues and this has just been realised at the normal service interval, so as it has been fine like that, it won't change unless you get corrosion/any other issues whilst leaving it exposed.

I would use electrical tape or maybe even some sort of sturdy cable harness on all 4 end points. The region where the wires are left exposed to keep them protected, in case of any vermin or service center foul play. I say service center foul play as the yellow slit wire looks like a clean cut, in my personal opinion. Who knows Covid has been hitting everyone hard, maybe vermin did bite the white wire as it looks plausible, the plastic being pushed outwards from pulling/bite? If one has been bitten what are the chances of a 2nd or 3rd, no one would know/assume any different?

You can always go to a different center for a second opinion to specifically diagnose those two ignition coil packs to see if there is any power loss/deficiency in the electrical current or whatnot. This could be way cheaper I reckon and peace of mind.

If the $500 + tax is for the parts and labour cost for replacing the two coil wirings. Now the question is what do they mean by that, are they going to strip the whole wiring harness and put a new wire from the start and end point, or will they link one up at the half-way point hidden in the other cable harnesses or what? As one would definitely not warrant a $500 + tax cost whilst the other possibly may?

As a side note. Never for the life of me heard of an engine shampoo being a recommendation, unless someone spilled oil or some other fluid all over your engine bay by not using a funnel. Can understand its aesthetic value otherwise seems like a gimmick. Maybe its common in your region (assuming the US based on $) no clue. Also your engine bay looks pretty clean based on photos posted, would be interested what it will look like after shampooing.

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