Driving in my neighborhood, the auto tranny naturally wants to stay in the most fuel efficient gear, but going slow (~25 mph) up a gradual hill causes the engine to make a slight rattling noise? It instantly goes away when I accelerate or drop it down to 4 manually. I wouldn't think this is causing any harm. I am curious what may be causing the noise to happen. Any ideas or explanations on what is happening?
Engine rattle noise at low speed??
- Thread starter OilGuy
- Start date
SGT_OKINAWA
Member
- :
- 2010 Mazda CX-7
1. Truly hard to diagnose over the internet.
2. Are you sure it's NOT engine KNOCK? (I.e. cheap GAS?)
3. You're going to have to describe a lot more and...
Provide make, model, miles, engine size, what you've done to the care as far as modifications, any problems any other places and is it an accident car?
Good luck!
Peace!(rei)
2. Are you sure it's NOT engine KNOCK? (I.e. cheap GAS?)
3. You're going to have to describe a lot more and...
Provide make, model, miles, engine size, what you've done to the care as far as modifications, any problems any other places and is it an accident car?
Good luck!
Peace!(rei)
No mods, I don't use bargain gas, it's just a bit annoying in my 08 Sport. I just drop it down a gear manually or accelerate a tad to get it to shift down. Didn't know if others had run into this much or not - guess not
Probably just tuning the tranny for max fuel economy at all times - even if it makes a rumble at low speeds.
Probably just tuning the tranny for max fuel economy at all times - even if it makes a rumble at low speeds.MazdaSailz
Member
So Weird. My Mazda3 does the same thing at around 40MPH and the RPM is Between
1-2K RPMS. Makes a rattling noise like a belt whining or something scrapping.
1-2K RPMS. Makes a rattling noise like a belt whining or something scrapping.
heywatchit
Member
Wow. This is exactly what I experience in my 2006 Maxda5 automatic. It ends to happen under 2 circumstances.
1, When I come to a stop, typically when the engine is cold (first 15 minutes).
2. when the engine is under very light load regardless of speed. I often hear it when cruise control is maintaining speed on a flat or declining surface at 50-60 MPH.
Sounds like a knocking engine. I hate it.
Scott
1, When I come to a stop, typically when the engine is cold (first 15 minutes).
2. when the engine is under very light load regardless of speed. I often hear it when cruise control is maintaining speed on a flat or declining surface at 50-60 MPH.
Sounds like a knocking engine. I hate it.
Scott
anthonym10
Member
- :
- 2006 Mazda 5 Grand Touring
This is exactly what my 2006 Mazda5 is doing. I can't figure out what it is. It sounds like it is coming from the belt side of the engine. I have been able to duplicate it manually by putting in park or neutral and revving the engine. Otherwise it seems to happen persistently with cruise control on (while driving on the highway) and sometimes at stops.
Has anyone isolated this noise? I read in another thread that a knocking was attributed to the AC clutch. Not sure if it was the same behavior as we're describing though.
More pressure from the right foot! Seriously tho, the OP's description sounds like engine knock..so it might be leaning out a little..you didn't mention any codes so no issues there. Even if you don't use bargain gas doesn't really mean much. Try a different station..if the brand you use now uses oxygenated gas or it's a blend, see if you can find a station that uses unblended gasolinie. Down here, the Valero chain of gas stations don't sell blended gas, so that's what I use in my cars.
Are the Fuel filter, fuel injectors and plugs okay?
To the other poster that has the same noise when coming to a stop? I'd say that's something completely different. I'd say that's the universal exhaust/cat converter shield rattle..
Are the Fuel filter, fuel injectors and plugs okay?
To the other poster that has the same noise when coming to a stop? I'd say that's something completely different. I'd say that's the universal exhaust/cat converter shield rattle..
On my 2006, I had a knocking noise from the engine on the passenger side. The noise would come and go and it seem to be independent of the engine speed. I checked the idler and alternator to see if they were the source. The mechanic also though it was a bad bearing on the alternator, but when he had the car up with the engine running he discovered it was a bad AC clutch which also explain why the AC was not working properly. The AC would stop blowing cold air when coming to stop light after some highway driving.