OK this is a rat in my pickup engine compartment  but it still runs, and it came back for more 

It's extremely common.

 

My daughter's Aunt has had this twice and both times the trucks went into limp mode and the Toyota dealer rewired it fairly cheaply.

Had my motorcycle rewired because of muse as well. But luckily only once for 10 years now 

Had the same on the scooter last year.

Got this from Big-C, sprayed it on the bike and the floor area where 

it's parked, been ok since.

 

tried to flush it out with water- fly spray-WD40 its still there, I was so impressed with its ability to hide I bought it some sweeties from the local hardware shop.

I live up in the mountains in northeastern Thailand. My house has an open garage underneath it. My truck is constantly invaded by mice They chew wires and water lines. They also get inside and chew on the seatbelts and seats. I have two mousetraps in my car, and usually catch a mouse once a week, but they just keep coming! 🥹

This happens regularly, or squirrels, or something similar, get into the outdoor unit of the air conditioning, but usually into the car's ventilation system, where they can't get past the air filter located directly after the fan (MU-X), resulting in regular replacement of the chewed-up filter and removal of the baby squirrels, sometimes still alive.
Incidentally, for a Toyota Fortuner, you could get special protection for this, which Isuzu does not have.

I live in a rural village in the south. First problem with my new car: local cats decided the engine bay was a warm hotel — slept in it, urinated in it, the works.
I put down those plastic spiked cat mats under the car and that stopped them.

A month later the rats stepped up. They chewed through my cabin air filter, so I installed a steel rat-guard over the intake. The rats weren’t impressed and just switched to nibbling the engine soundproofing instead.

Solution turned out to be… cats. I adopted a pair, and the rat problem basically vanished.

I still get the occasional small snake hiding inside the bottom of the door cavity, but they can’t get past the inner door seal. They don’t cause any damage — and honestly, they probably help keep the rodent population in check.

Toyota and other have been making wiring harnesses that are soy based for the coating and the rodents love it. Been this way for 8 yrs or so

Lots and lots of ruined cars/trucks because of it, google it for hours of reading

 Pepper in small mesh bags in the engine bay will keep ALL the nasties away

Get a cat...

Vegetable oil were 100% used in the manufacture of cable insulation until banned in Europe, replaced by mineral oil.  Car manufacturing countries that still use vegetable oil are now mostly in Asia.

 

Wife has a (SUV) MG that has had wiring damaged/eaten/chewed 3 times in 4 years, luckily insurance covered the replacement cost.  

Have 4 mouse (Snapping) traps 2 inside car and two in the engine bay, sadly many 3 lizards are caught for every mouse. 

Cats are the best deterrent, but we have 8 dogs 4 being GSD's who sadly kill any feral cats. 

My truck wouldnt start, and the cd player didnt work!

😬😳🤔🚀

 

Use moth balls to deter them!

4 hours ago, WDSmart said:

I live up in the mountains in northeastern Thailand. My house has an open garage underneath it. My truck is constantly invaded by mice They chew wires and water lines. They also get inside and chew on the seatbelts and seats. I have two mousetraps in my car, and usually catch a mouse once a week, but they just keep coming! 🥹

Oh yes I forgot the mice eat my window washer pipes!

Isuzu wanted a small fortune to fix it!

😬😳🤯

Depends on the flavour of the wiring sleeve.................🐀

12 minutes ago, cowellandrew said:

My truck wouldnt start, and the cd player didnt work!

😬😳🤔🚀

 

Use moth balls to deter them!

.......and any passengers..........🤢................🤭

4 hours ago, Grumpy one said:

 Pepper in small mesh bags in the engine bay will keep ALL the nasties away

Why ?? Do the Nasties start SNEEZING ??

4 hours ago, Grumpy one said:

 Pepper in small mesh bags in the engine bay will keep ALL the nasties away

Why ?? Do the Nasties start SNEEZING ??

4 hours ago, Grumpy one said:

 Pepper in small mesh bags in the engine bay will keep ALL the nasties away

So Do the nasties start SNEEZING ??

Last service the mechanic said there were rat droppings in the cabin air filter. Put two jam jar tops filled with rat pellets under the car when I got home. Checked the next day and both tops were empty. Was worried by how many rats there were. Same again the next morning after topping the pellets up. Topped up again and put my trail camera under the car to see what was going on. No rats. Just the neighbours cat eating it all. Cat survived so I presume it was throwing the pellets up at some point.

Controls wiring in my electric steering system were destroyed some time ago.  Had to have car transported on a flatbed truck to dealer for repair.  Rat spray available from many sources seems to work well.  Fortunately insurance covered my cost for the repair which was quite high..

Martens do this usually!

3 hours ago, transam said:

4 hours ago, cowellandrew said:

My truck wouldnt start, and the cd player didnt work!

😬😳🤔🚀

 

Use moth balls to deter them!

.......and any passengers..........🤢................🤭

You joke, but mothballs (if you can find them) do deter pests like mice, rats, (and people)

A former car of mine had soundproofing fabric in the engine compartment and one year I returned from a 3 month trip to find evidence of mice in the compartment and some fabric gnawed away.

Since then I've been sprinkling a few mothballs in and under the engine compartment. My current vehicle doesn't have the fabric but I am still concerned about the wiring.

 

Oh and once, I bought some mouse & rat killer pellets from a local DIY store. Useless - the rodents just ate, and presumably enjoyed it, so I ended up attracting them to my garage instead of exterminating them 🤬

Mice got to the  harness wiring  / Honda Civic   dealer had to dismantle nearly half the engine to get to it...

I had a field mouse gnawing at the undercarriage of my pickup. I was on a trip and while driving the electrical system went haywire. Lights flashing and total electrical failure. I was fortunate my pickup was able to get started after stopping at a 7 on the highway. Luckily for me the dealer where I bought the vehicle was where my sister in-law worked. They had to replace the entire wiring under the pickup. 

19 hours ago, Blueman1 said:

Why ?? Do the Nasties start SNEEZING ??

That I can't answer, never stay in the engine bay to find out.

From experience, rats, mice and snakes don't like the smell / taste, moth balls or sulphur also work

On 11/20/2025 at 12:31 PM, cowellandrew said:

My truck wouldnt start, and the cd player didnt work!

😬😳🤔🚀

 

Use moth balls to deter them!

Just got some mothballs from Tesco/Lotus's  how long do the last ?

How do I stop feral cats from sleeping on my new car roof ? Tried pepper and spray that doesn’t kill them. One of them was sick and getting the stain out is impossible.,

13 hours ago, geisha said:

How do I stop feral cats from sleeping on my new car roof ? Tried pepper and spray that doesn’t kill them. One of them was sick and getting the stain out is impossible.,

I use the soft plastic spiked cat mats on the ground under my engine — that solved the engine bay problem for me. My roof has never been an issue, but you could try putting the mats on the roof itself, or just use a car cover.

18 hours ago, geisha said:

How do I stop feral cats from sleeping on my new car roof ? Tried pepper and spray that doesn’t kill them. One of them was sick and getting the stain out is impossible.,

The old pickup is 2008 I use a PVC tarpaulin from Lazada, the old paint pot under the truck is to stop the dogs getting black off the exhaust LOL