Mechanics

CAR NOISE, HELP!

2007 Chrysler PT Cruiser • 67,000 miles

Hello, I am very concerned about my car. When I turn it off it still makes noise, sort of as if it still was on but not as strong as when I actually turn it on. Usually when I turn my car off, it doesn't make sounds, so I dont know what is happening. I own a PT cruiser 2007. The noise comes from were the engine is. I dont know if it is the battery.I dont know much about cars. Please help me, it just happened a moment ago and I cant leave now to have it repaired, so I am afraid that later on it wont turn on. Thank you for your attention.
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Yunpo
January 28, 2011.




Depends on what the noise sounds like. If the radiator fan is running, suspect a shorted electronic relay. That is somewhat common and will kill the battery in ten to twenty minutes. If you're hearing a high-pitched whistle, that may be the Engine Computer. It goes to "sleep" mode in about 20 minutes, then the tone will stop. That is normal.

Caradiodoc

Caradiodoc
Jan 28, 2011.
Thank you for replying so fast. Actually I think is the fan, becaus that is what it sounds like. And it did kill the battery after around half an hour.I had to use jumper cables and I finally took it to a carshop. However I am afraid they may charge me a lot. What does "shorted electronic relay" mean? And around how much would it cost me to fix it?
Thank you so much for your help and attention.
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Tiny
Yunpo
Jan 29, 2011.
I'll have to defer to my experience on 1999 and older models, but I think yours will be the same. Previously there was a simple, common sense relay in the under-hood fuse box that cost around ten bucks. As cars became quieter, customers started complaining that they could hear the radiator fan run from time to time. To address that, they now use a small computer module that can vary the speed of the fan motor from very slow to full speed. They don't run the fan any faster than necessary to get the job done. They call that module the fan relay but it really is a lot more than that. Any time they add another computer module, they add to the vehicle's unreliability. (Be happy you don't have a GM product. They make the majority of their profits from selling replacement computers that have to be purchased at the dealership, and must be programmed and installed by them. By the year 2002 they can have up to 47 computer modules)!

These fan relays used to have a real high failure rate but we don't hear about that much anymore. I sell used relays along with other car parts at an old car show in WI. I get ten bucks for them but I don't know what new ones cost. It shouldn't take more than about a half hour to replace it.

Caradiodoc

Caradiodoc
Jan 29, 2011.

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