Hi all,

I have a quick question for you all. Every so often when I start my Neon RT, there is a loud noise. I don't know where its coming from, but I think its the exhaust system (IT sounds like its from the engine when I am in the car, but those outside say its the exhaust) The noise only seems to occur if the car has been sitting all day in the sun. If I leave the car in the garage overnight, or all day in the garage (on a hot day), the car starts perfectly. Its just loud when its been sitting all day and its been warm outside. It seems to be a loud vrroooomm noise which lasts 2-3 seconds, then everything is fine again. If I stop the car and re-start, its fine. Its just that initial start.

This may sound a stupid question, but could there be petrol or something in the exhaust that gets hot after sitting there all day and then something happens when I start it.

Or could it be something like the exhast system expanding in the heat??????

Its just odd that on a hot day in the garage its is fine, and overnight it is fine

I am sure someone here will be able to help me.

I look forward to hearing from you all

Regards

UKNeonRT

 

I guess you need to explain the noise a little better, you said it was a "vrrroom" sound... Does it pop or make any other noticeable sounds when this occurs?

 

Hello, sorry for the delay in replying - i have been on a long vacation!. Let me see if i can explain it better. Basically it only seems to happens when the car has been sitting all day when it has been hot. It can sit all day in cooler whether and when you start it its fine. The car is always fine first thing in the morning - its in the garage overnight. There are no other noticeable sounds from it apart from the vroom noise. I've tried to work out exactly where the noise is coming from. At first I thought it was the back of the exhause, then the engine, but now I think it is right underneath the car - so I guess it could be the middle bit of the exhaust

I'm not up with how cars work, but if the car has been sitting in the heat all day, could the exhaust metal be expanding, and when I start it something to do with pressure?
Could there be a hole or leak in the exhaust?

If I turn the car off after the noise has hapened - whether this be straight away or after a few miles and then restart the car, it is fine - no noise. I can't help but lean towards it being something to do with the heat after its been sitting there all day cos if its a hot day and its been in the garage and I start it, its fine

I'm worried about it doing the car some damage

Any advice would be greatly received

 

Does it sound like a back fire or just a loud rev from the moter it could be some unburnt fuel..

 

one possibility is the rear brakes.
maybe when the brakes and rotors got changed, they r too tight.
i met this problem on my dodge stratus.
so maybe u need to release it....or...i dunno....i'm not good at fixing car.
i think the main problem is ur hand brake is too tight. or ur rotor is not straight no more.

r these help?

 

Hello,
It seems more like a loud rev. Its quite a deep sound. The RPM's stay at normal start up speed. Ity only lasts a second or two, then its fine and it drives with no problems. So is it possible it could be unburnt fuel? would it be in the exhaust?

 

Yes it does sound like unburnt fuel but i dont know where it would be at without hearing the car... You may want to take a look at your injectors and see if thay are leaking.