Why does my Mercedes make a rattling sound when I start the car?

Rattling Engine. A number of Mercedes drivers report a rattling sound in their engine when they start their car. This happens more often in cold-weather locations. The cause of this common problem is usually the car’s belt tensioner. This part is what keeps the belt tense as it runs all of the engine accessories.

Why does my Mercedes C class run rough off-idle?

21 people found this helpful. Hmmm, so what you’re saying is it idles ruff but passed that part of the test and runs smooth off-idle but fails that part because it’s running too rich ( too much fuel). If you had a vacuum leak at the throttle body you’ll be running lean not rich as you are now.

What are the most common problems with Mercedes cars?

Common Mercedes problems that are reported by drivers are: Rear suspension rattling. Electrical system malfunctions. Rattling in the engine. Engine cooling problems. Ignition switch failures.

Why does my Mercedes not start in cold weather?

This happens more often in cold-weather locations. The cause of this common problem is usually the car’s belt tensioner. This part is what keeps the belt tense as it runs all of the engine accessories.

Why does my Mercedes Benz W203 make a rattling noise?

My 2001 W203 (with 79,000 miles) has a knocking/rattling noise coming from the front suspension. It occurs at any speed. Even moving very slowly, any undulation of the pavement causes a knocking/rattle. I’ve read that it may be the sway bar end links.

Why does my C class car make a rattle noise?

Thanks for your thoughts. check your guide arm bushings, on the c class they are known to fail often. they cause a clunking noise in the front end going over bumps. will also cause noise on any road. My car just started making a rattle/klunk as you describe and I’ve been trying to identify the source.

Why does my car rattle when I Turn on the oil?

The engine “rattles” until the oil pressure comes up to normal. After the engine has been run, the oil pressure comes up within a second the rest of the day. (No rattling) Does the oil pump have to stay primed? Is there a check valve in the oil pump intake? The pump has been checked ok by mechanic for pressure.

What should I do if my car rattles in cold weather?

In the cold weather, a full-synthetic oil will enable the engine to get oil pressure sooner too, as the oil won’t be a puddle of jelly at below freezing temps. Good luck. Chances are no damage is being done, but I think I would change out the oil filter.