I hear this noise when idling what is causing this?

i have a mazda 3 2010 model. i hear this “rattling” noise only when i am idling at a stop. i also notice that if i just put the car into park the noise disappears. it only seems to happen when idling on drive at a stop. what is causing this and is this a sign of bigger problems down the road? i am trying to upload video its not allowed and i try to upload audio recording and its not allowed. the only descriptions i can say is that the car sounds normal driving but when stopped at stop light with automatic transmission on drive with the brakes applied since i am at a stop light, there is a rattling type of noise. i turned off ac to discern if it is related to ac and there is still a slight rattling sound. diagnosis and consensus please.

Bring the vehicle to a shop and tell them what you just described.

The first thing they’ll do is inspect for a loose exhaust heat shield.



+1 to @Tester 's post. The second thing they’ll check (or at least I would) is the serpentine belt tensioner.

Another idea, if you hear the rattling sound when stopped in “D”, but not stopped & idling in “N” or “P”, that makes me think there might be a transmission problem. The first step is to make sure the transmission fluid it at the correct level. Was any transmission related work done by your shop a few days/weeks before you started to hear this sound?

The OP (according to past topics and post), just needs to find a reputable shop to take all his/her vehicles to, they don’t seem to do any of their own repairs anyway…


I expect the OP already knows they’ll have to secure shop services. This is what they are asking from the posters here:

i went to autozone and had them plug into my car and this is what they gave me. does this correlate to the symptoms i described? the reason i am on this forum and not going directly to mechanic is because this junk of a car has already cost me in repairs and if you note that i am driving around this car i am short on funds. can someone tell me whats up?

i also want to add that when i hear that noise im complaining about when im stopped at a stop light if i switch the automatic transmission to neutral the rattling noise goes away

The P0841 diagnostic code might indicate the transmission fluid level is incorrect.

if that is the case and its been right all this time then what is the issue is there a leak?

Possible. Do you have a way to get the level checked? That’s the first step. Is the car equipped w/ a transmission fluid dipstick?

Neither code would make a noise.

And diagnosing an indescript noise over the internet is nearly impossible. You need eyes, ears and hands on to find.

Just drive it and ignore the noise. Turn up the stereo. That is what you do with a beater.

i just checked transmission fluid levels. the dip stick has notches and then a twist above the notches. the fluid level is around where the twist is way above the notches. if its overfilled it hasnt given me issues previously.

my problem with this car is that i bought it when used car priced were skyrocketing. it cost me $13,000 and i still owe just over $9000. a 2010 mazda cost me this much.

Are you checking the level with the engine running and at full operating temp on level ground??

its on the drive way. when i checked it was minutes after i drove the car to autozone. the engine was off when i checked. i figure if that was considered cold then more than likely the level would be higher when its warm. i just want this car to last me till i pay it off after this experience though i never want to buy another mazda they seem to have too many issues. the only thing great about this car is that it turns really well. the handling of this car is pretty fun especially when exiting freeway on a tight circular turn.

None of which have any bearing on the problem you face.

You don’t work on your own car so any diagnosis we give is of limited value since a shop would (and should) do their own and you can’t sell the car to get away from it.

You also condem an entire brand because a 14 year old car with ??? miles in it needs maintenance as well as repair. Go figure!

You are between a rock and a hard place… sorry about that… The way I see it, you either need to take it to a shop and pay for repairs or ignore it.

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Didn’t answer my question, I have 2 driveways, one is perfectly flat and the other is like a ski slope, very steep, so I ask you again, was the vehicle on a FLAT surface when you checked the ATF (or any fluid) fluid level???

Engine must be running and at operating temp and on a flat surface (like a house garage)…


To check your transmission fluid levels at home, simply follow these steps:

1. Turn the car on. The engine should be warmed up to check the level.
2. Find the transmission fluid dipstick. On front-wheel drive cars, it’s usually located to the right of the oil dipstick. Check your owner’s manual if you’re having trouble finding it.
3. Remove the dipstick and touch the fluid, moving it around between your thumb and forefinger. The fluid should be nearly clear, with a pink hue. If it looks dirty or gives off a burnt smell, take it to a service center for replacement.
4. Use a rag to wipe off the dipstick. Then insert it back into the vehicle. Pull it out again and check the level. If it’s under the “Full” marking, you’ll need to add more.
5. Use a funnel to bring the fluid level up to the right spot. Be sure not to overfill it.



Seems to me that you have 3 choices then…

A) Do as mentioned and drive it to it blows up… (not a long term plan)

B) Find away to increase your income, ie, part time job, extra hours at work (talk to your boss), mow yards, wash windows, clean gutters, just find something that someone needs done that you can do for some extra money…

C) Lower your out going expenses, ie, drink water only, no soft drinks, star bucks McDonalds, pack your lunch, peanut butter and jelly or bologna sandwich are very cheap etc etc, no cable or satellite TV, Netflix etc etc etc…

A good friend of mine was talking about being broke and then would Uber McDonalds, I jumped his a$$ about being stupid, he stopped and started packing his lunch and saved a lot of money at the end of the month…

That being said, we don’t need to know your finances or eating habits, so don’t share, what you do with your money and how you eat is your business not ours…lol

Sorry you are having issues and best of luck to ya…


I did that my entire working career at good paying engineering jobs. Frugal living allowed my wife to stay home and take care of the children. We also live in the best school district in the metro area, leading to excellent educations and now good jobs for our daughters. Finally, a safe and well funded retirement.