Hi there

I've read alot about people with rattle noises due to ****ty TC and dont think this is it. Now I hope some of you could help me out with Identifying this sound.

If the engine is cold it takes a moment before the rattleing starts, and as the video shows it disappears when reving alittle (everything above 1200 rpm).

CEL is on, but no error's to be found.

Please help! :O :O


W203 C180K 2003 M271

 

How many miles? Any maintenance history on the car? Such as timing chain replacement?

 

Does not sound good, my moneys on the TC chain. As Samaritrey said... how many miles, has it had reg services all its life?

 

Would hope not, previous owner have been driving with that sound for half a year.
It's at 263k km and all services from 05 - 13 have been followed.
So my question if it is the TC, how bad could it be.
The workshop couldn't find out what the noise was but recommended to changing the Timing chain. But also thought that it could be cam adjuster??

Any ideas?

 

That sounds like more than chain. At your mileage I would replace the chain & use once tensioner anyway. It could be a cam adjuster & it could also be a hydraulic lifter that is toast or worse.

Whatever it is going to require some exploratory dismantling to find the cause.

 

*UPDATE*

The chain looks good and tight, but one coil and spark plug were rather wet.
might have missfired?? anyway, any possible sensor that could cause this?

maybe vacuum pump?

 

What I discovered when I did my chain is that even though it looks tight across the top, there may me slack on the tensioner side due to the engine's direction of rotation. Your chain may still be stretched, you just can't see it...

 

hi guys.
new to this forum so please bear with me. I have the exact same issue as Skelterize. Car rattles like a diesel engine on idle (but ONLY after it gets up to its normal operating temp). The rattle stay below 2000rpm and disappears when revved above that. Timing chain was replaced. Sprockets were replaced. Tensioner and crank case pipes were replaced.
The noise seems to be coming when the camshaft timing clip "unlocks" and moves about 10 degrees.
Dont know if that makes sense.
please help if you know whats happening.

 

Same thing I had, you might be missing a spring on the cam adjuster. It operates under pressure, if missing the symptoms you describe will appear. Check it out and see if its missing :-)

 

Thanx Skelterize
will check this out. seems like the "pin" that locks the camshaft at TDC is not locking anymore. I will need to strip it to check. Another pal of mine had his doing this and found out that the "pin" and spring and circlip where missing. must have been some vibration/misfire that would cause this to jump out.

 

Hi Skelterize,

just out of curiousity - is your car with the video of the engine rattle at the beginning of this thread fixed yet? How long have you been running the car with that rattle?

 

hi guys,
just wanted to let you guys know that i found the issue with the noisy idle issue. Seems like one of my cam adjusters were not locking. seems like the "pin" and spring as well as the circlip retainer had jumped out (picture).This was due to the fact that my cam gear had a crack.

getting a new gear and will resolve. The stuff up is looking for those retainers and clip in the engine

awesome forum guys

 

The sprockets and circlip retainer look good on my engine but stile have the same sound, and also have a CEL for "A" camshaft position actuator circuit, which are replaced.

 

After almost a year of struggle, nightmares, hundreds of MB bulettins read, research on deepweb, hours of phone calls, i FINALLY found a wise man who told me the secret about this ancient and to many people so annoying M271 engine problem. I know my Hell which I passed through, so I needed to sign in to this forum to share my Revelation with people who gave nice amount of money to drive a Merg, just because it's reliability and durability tradition, but woke up one day with a "dissapointment with a shiny tri-star 'aim' on the hood" in a garage. It is a bad feeling. Everyone says you have a nice car, but you are shamed inside yourself. Drive and cry. But, Salvation Day has come. Almost all of us was focused on mechanical nature of the problem, but the Man opened my eyes today. The first cause of this problem is an electronic fault. Bad wire harness from ECU to magnet actuators. In some RARE cases, it may happen that the output on the ECU is burnt as well, in that case get ready to open your wallet wider for another ECU and flashing the map from the old one. As far as I understood, those magnets which regulate timing of the pulleys draws some significant power, so those cables are slightly different than ordinary copper wire (which I realised by myself, because when I try to bend the wire it acts like it is from steel, even has a spring effect. I thought it was burnt copper wire, it seems like that,), it is obviously some kind of alloy or some other **** which has burnt somewhere on its way from the ECU, so exhaust magnet lost power, it wasn't regulating oil flow in the pulley and too much pressure pushed out a locking bit spring. So, you can change adjuster, but just doing this doesn't solve the source of the problem, first time when you go mad (like I use to do often) and push it up to 5.500 rpm, there is very high possibility that everything go to hell again. If you drive on LNG or CNG, chances are even higher. So, my warm advice is to find a good car electronic guy beside a good mechanic, who will check the harness and connect a new wire all the way from the ECU to the exhaust magnet. I highlight that this is a common problem, and it is always exhaust adjuster which dies because it's magnet was out of power supply, never intake one. Don't ask me why, probably it's something with wires in the harness, and those wire for exhaust magnet maybe bends somewhere under sharper angle and burns there... . They are all sealed in those "console" where also wires for the injectors and camshaft sensors are together. So, finally I will get some old good sleep.

I hope this will help someone, eventhough this topic is old. Mergs never get old...

 

Thank you so much, your explanation was so detailed and so similar to my friends w211 e200 kompressor that you gave him new hope in saving his car, thank you so much!!!