I have an intermittent failure? 2001 V8. They work sporadically and I can't seem to figure out what's going on.

 

I guess obvious things to check are water and dirt on sensors. My sensors never work correctly when they are wet.

But ideally you should provide more information on the problem. What exactly is going on?

 

you can replace them very cheap. I saw a set on ebay for like $35 new.

 

Mine go bonkers when it gets really cold out even if I make sure they are clear of snow & ice. When I back up they will do a constant beeeeeeep until I out her in drive. Luckily I haven't run anyone over by ignoring it. lol

 

Well, I have the same problem sometimes. They work fine until it gets really cold. I don't know how cold it is where you are but for me it happens usually because the exhaust fog creates that classic cloud behind the car when its really cold so this makes the sensors think that you are about to hit something. I also sometimes find that there is a very fine layer of frost over the sensors (so fine you can't really see it) and that is enough to mess with them. On any other day, they work just fine!

 

Unfortunately quite a few s types have issues with water leaking into the trunk,this in turn can corrode the wiring in the back up sensors causing them to work intermittantly.

 

The problem is totally random, wet or dry, hot or cold, clean or dirty, I think I might investigate the wiring as suggested.