Q: Rattling noise upon startup, slightly when idling, and constant during acceleration.

asked by on

I'm concerned it may be a timing chain tensioner because I've read that they do wear on a lot of these cars. I'm just not sure of the characteristics of a failed/damaged one. I do also have a check engine light for the bank 2 O2 sensor stating that it's running below threshold so I'm hoping that my catalytic converter has failed and components are rattling about inside. I do feel a slight loss of power as if it's exhaust related but I guess my question is, when the timing chain tensioner needs replacement, how often or when should I here rattling.

My car has 170000 miles.
My car has an automatic transmission.

The rattling may be coming from either one. The only way to tell is to listen to see if the noise is coming from the timing chain or front of the motor. The catalyst noise would be mostly from around the exhaust area of the catalyst. If you have a bad tensioner or guides the noise will be there constantly but will be lighter or heavier as engine increases or decreases. A catalyst rattle may come and go and not really be as consistent.

I’d suggest you get some help from a qualified mechanic who can diagnose the source of the rattling noise and your Check Engine Light in person. Once the issue has been pinpointed the necessary repairs can be made.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Rattling noise upon startup, slightly when idling, and constant during acceleration.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: witch solenoid causes the drive & revers to go out in the transmission

If the transmission is not engaging in drive or reverse, that is probably a valve body fault, for example with the manual valve in the valve body. Of course, double check the adjustment of the shift linkage so that you...

Q: When the car is about to just fully stop it makes a squeaking noise to what seems to be in the rear breaks

Hello. This is likely the result of the brake pads wearing down to the "wear mark" which a certain thickness on the brake pads designed to alert when it is times to consider replacing the brake pads. This is not...

Q: when trying to start my 03 Lincoln LS (v8) all i get is a singal click.and thoughts?

Hi there: It's very common for multiple battery-related components to all wear out around the same time, including battery cables and the battery temperature sensor attached to the bottom of the battery box. In some cases, when the battery temperature...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...