Anyone know how to keep a cat out of your engine bay?

New neighbors brought an outside cat.  I've found it multiple times roosting underhood in the truck's engine bay.  Despite how little I drive the truck these days, I know that sooner or later I'll start the truck and just hear a cat screaming.  Then I'll have to hose cat guts out from under the hood, I'll have to deal with an angry neighbor (who I've already complained about this issue to,) etc etc etc.

Anyone have a good trick to keep the cat out?

At least I know where the cat likes to hang out in the engine bay, so it might be easy to prevent it from sitting there.

Citrus-scented sprays in the engine bay?

Temporary workaround: Honk the horn once before starting the engine at home. If you hear one bang and don't see/hear the cat run off, check for a cat in the engine bay that died of a heart attack.

Encourage the neighbor to have the cat spayed or neutered if it isn't already, so that you don't end up engineering dumber cats into existence

The good news is they don't have time to scream before the belts or fans make minced meat. 

The bad news is, the hose won't clean up the mess. 

Bang on the hood before you start it. 

You might try these placed strategically. 

Pretend it's a big diesel truck and let it idle all night long?

put a dog in the engine bay?

Actively try to get the cat to go in. Cats are shiny happy people, and will do the opposite. Give that cat some reverse psychology. Cats love reverse psychology. 

Shotgun 

Snowdoggie (Forum Supporter) said:

Wife has been wanting another dog, and that is the right engine, so I know it'll fit!

Record the sound of the cap popping on a container of Advantage flea treatment. Play the recording a few times before getting in. you will never see the cat again.

And maybe the cat is in there because of something else, like mice.  

Just a thought.

In reply to Noddaz :

So then you get mice, cats and a dog rummaging around in your engine compartment.

A coyote also has to show up at one point.

Snowdoggie (Forum Supporter) said:

In reply to Noddaz :

So then you get mice, cats and a dog rummaging around in your engine compartment.

A coyote also has to show up at one point.

No, not at all.  Just maybe there is mice living in a truck that isn't used a lot.  And the cat is looking for them.

This cat is your buddy, just don't let it know. A knuckle thump on the hood as part of start up procedure is a small price for the extermination service.

Or get one of these for the grill.

Cat repellent sprays are a thing.

Just leave the cat installed, they don't cost any power on a from everything I've read on the internet and they are good for the environment. 

This would do it: 

Park overnight in a bad neighborhood and someone will remove your cat for free?