Skip the auto shop - Our mechanics make house calls

Q: Car rattles after starting

asked by on

My car starts with a rattling sound, but then it goes away after driven a bit.

A: Hi. It's difficult for me to say withou...

Hi. It's difficult for me to say without hearing the noise firsthand, but there are a couple things that come to mind. The first is the hydraulic valve lash adjusters. The lash adjusters use oil pressure to keep the lash between the rocker arm and valve at a constant rate. When the engine is cold, it sometimes takes oil awhile to reach the adjusters. As a result, you have a rattling or tapping noise when the engine is cold. This is a common problem with the vehicle you have. The second thing that comes to mind is an exhaust leak at the manifold. This is more noticeable when the engine is cold and often goes away as the engine warms up. This is because the exhaust manifold metal expands. My best advice is to have a trained mechanic, such as one from YourMechanic, listen to your vehicle's noise.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Mileage light

The instrument cluster assembly and the radio do not have a anything in common except the instrument illumination. Do your dash lights work at night? If they do, then the radio will have nothing to do with it. The...

Q: My car failed the smog test and two codes came up: P0422 and P0432 Both Catalyst 2 Efficiency Below Threshold Bank 1 and Bank 2.

Hello there, thank you for asking about your 2003 Mercedes-Benz ML350. The catalytic converters have to be replaced. You have 4 options for parts and labor: 1. Have a certified technician from YourMechanic come to your home or office...

Q: Truck overheated, now won't start

From what you've described, the engine overheated causing engine damage. When you first started to overheat, you should have stopped the engine and had the vehicle towed at that point. You may of cracked the cylinder heads if you ran...

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...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...