[_F30_UK_]

Supposed to be going on a 4 hour drive. Went to start the car and got a message saying "Outside temperature -40" and the engine light is on. Checked under the bonnet/hood and it looks like some mice/rats have cut through some wires at the top back of the engine.

What are these wires for? The problem is the other side of the wires goes into the engine black plastic bit so I can't pull them enough to join them together.
The other side of the wires plug into the airflow box thing.

View post on imgur.com

[Opie55]

You don't say if the car runs ok. Probably not many people will know offhand and would have to trace them to where they go and see what they connect to. As you likely realize, "engine black plastic bit" is not terribly helpful.

[Opie55]

Also, since the engine light is on you can probably get a clue what the wires are by having the stored error codes read. In the US most auto parts stores will do it for you.

[_F30_UK_]

Car runs okay, but has an engine light and thinks the outside temperature is -40. I have dropped it off to local garage now so see how it goes.

[Billfitz]

They don't just feed on wire insulation, they nest. You can see signs of that in the picture. If you have it garaged you're more likely to have them nest than if you park on the street. After having one do a job on my car I put one of these in my garage. It catches on average a mouse every month.

https://www.amazon.com/dp/B09NKZ2G1J...NsaWNrPXRydWU=

[a5m]

That's terrible to hear. Hopefully it's a simple fix with resoldering the wires. As suggested I'd have the code(s) read to get an idea.

This has happened to me on my WRX. A baby rat was trying to make a nest around my battery. How did I know? Got in the car to drive and he jumped out from under the hood and cowl area and tried to escape by climbing up the windshield but kept slipping down. Went back down and in after running across the windshield. Didn't see but I assume he ran away from underneath.

Anyway, peppermint oil is a deterrent apparently so went and bought some at Target. So far so good, but not sure if it's the peppermint or the trauma of what it went through that's kept it away. Regardless, I'm popping my hood to check before every drive and spraying it down once I return. Excellent.

[Billfitz]

Mint does deter rodents. I have it planted around the perimeter of my garden and it has greatly reduced my crop losses. The trouble with mice is you'd have to dip the car in mint oil to keep them away from all of it. The one that ate my wiring made his nest near the fuel filler pipe behind the wheel well liner. It took me forever to track it down.

[schernov]

claim it on insurance and have dealer replace the harness

[coupe36]

Originally Posted by Billfitz

Mint does deter rodents. I have it planted around the perimeter of my garden and it has greatly reduced my crop losses. The trouble with mice is you'd have to dip the car in mint oil to keep them away from all of it. The one that ate my wiring made his nest near the fuel filler pipe behind the wheel well liner. It took me forever to track it down.

:confundido0068: Oh, I saw a rat under my car, but I didn't know where it went.
I'm going to investigate. Rat

[eluded]

Sorry to hear that. I have traps set all around my car and every once a while somebody gets caught.

[mecheng77]

Based on the -40 reading it’s probably your outside temperature sensor.

Was the car stored outside for long periods of time?

[joesid]

I live in a rat infested city and park outside, so I know the struggle. I’ve already had to drop the lower engine cover once this year to clean out an absurd amount of leaves, trash, rat poop, etc. I sprayed diluted peppermint oil on both the lower cover and hood pad and have been checking at least once a week.

[natesi]

I put old fashioned mouse traps inside each wheel, just under the rotor, and I have been catching mice like crazy -- sometimes every day. This gets them before they even get into the engine bay, but I have a backup trap in the engine bay as well.

[_F30_UK_]

After doing some research, I decided the best option was to purchase some peppermint repellent spray. Arriving today so will be spraying it all around the engine area

[mecheng77]

Originally Posted by _F30_UK_

After doing some research, I decided the best option was to purchase some peppermint repellent spray. Arriving today so will be spraying it all around the engine area

Did you get it repaired, if it’s only a few wires you can get the professionally spliced

[mecheng77]

Originally Posted by Billfitz

They don't just feed on wire insulation, they nest. You can see signs of that in the picture. If you have it garaged you're more likely to have them nest than if you park on the street. After having one do a job on my car I put one of these in my garage. It catches on average a mouse every month.

https://www.amazon.com/dp/B09NKZ2G1J/ref=sspa_dk_detail_2?psc=1&pd_rd_i=B09NKZ2G1J&pd_r d_w=3XgGj&content-id=amzn1.sym.9f074495-da4d-4e1c-b407-69e85fa47fdb&pf_rd_p=9f074495-da4d-4e1c-b407-69e85fa47fdb&pf_rd_r=FW4PSAHMVJZT7RC18W24&pd_rd_wg =dV9AC&pd_rd_r=8c866a8d-df00-49fc-b39c-8105e36a51c0&s=lawn-garden&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0 aWM&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyRzNPUjhWQVUyU TRYJmVuY3J5cHRlZElkPUEwNTAzMzE2MTM0Q0U1RFZESzVMMiZ lbmNyeXB0ZWRBZElkPUEwNjU1MjgxMTVMTzVFTk9YUEpETyZ3a WRnZXROYW1lPXNwX2RldGFpbF90aGVtYXRpYyZhY3Rpb249Y2x pY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

What did they do to your car? Which wires did they eat?

[Billfitz]

Originally Posted by Billfitz

The one that ate my wiring made his nest near the fuel filler pipe behind the wheel well liner. It took me forever to track it down.

To be precise it chewed the insulation on the wiring from the fuel tank leak diagnosis module. This caused the conductors to corrode and eventually break. Rodents don't eat wire, they eat the insulation, which is made with soy. Once the copper is exposed to the air it will corrode. It doesn't help that manufacturers use wire of the smallest possible gauge and thinnest possible insulation, to save weight.

[mecheng77]

Originally Posted by Billfitz

To be precise it chewed the insulation on the wiring from the fuel tank leak diagnosis module. This caused the conductors to corrode and eventually break. Rodents don't eat wire, they eat the insulation, which is made with soy. Once the copper is exposed to the air it will corrode. It doesn't help that manufacturers use wire of the smallest possible gauge and thinnest possible insulation, to save weight.

I thought only Honda and Toyota used soy. What model do you have?

[Billfitz]

Honda and Toyota don't make wire. Neither does BMW. Most manufacturers use wire with soy based insulation, BMW among them. Soy may not be the problem, mice will chew on anything, but there seems to be more damage from mice since soy insulation started to be used in cars.

After doing some research, I decided the best option was to purchase some peppermint repellent spray. Arriving today so will be spraying it all around the engine area

There isn't an area in the car that doesn't contain wire, most of it inaccessible to us but not to mice.

[mecheng77]

Originally Posted by Billfitz

Honda and Toyota don't make wire. Neither does BMW. Most manufacturers use wire with soy based insulation, BMW among them. Soy may not be the problem, mice will chew on anything, but there seems to be more damage from mice since soy insulation started to be used in cars.
There isn't an area in the car that doesn't contain wire, most of it inaccessible to us but not to mice.

I realize they may not make the wire but there were lawsuits against Honda and Toyota for using soy based insulation. I think bmw uses pvc based insulation

[Billfitz]

https://www.reddit.com/r/Cartalk/com...nation_herein/

[wilbur_the_goose]

I keep my F34 in my garage, but the mice got to my Honda one day. Caused all sorts of problems - lost power steering, every idiot light was lit, and a whole lot more.

Had it towed to my trusty local independent and he fixed it for about $200. Told me mice are a common problem and had no idea how to keep them out of the engine bay.