Pauliescff

2005 c230k. 69000 miles and religiously maintained using Mobil 1 euro synthetic. On occasion, there is this noise on start up that sounds odd. It's not a metallic noise, more like a dull knock that lasts about 1-2 seconds. It occurs sometimes when hot and sometimes when cold. It doesn't occur everytime though. I have read about the timing chain problems with these motors and am trying to narrow it down. There are no warning lights and vehicle runs smoothly. I have read many different theories on what he source of problem is or could be. Timing chain, tensioner, cam adjusters, etc. All the folks that had the timing chain fail, did the noise occur on every startup it was it intermittent?

Norsk_Johnson

Hey man. I have the same car and since you didn't post a video, I am only going to assume we get the same noise upon start-up. Feel free to check out an old post of mine from last March. I have a video you may be able to see some similarities. I also go some advice from some of the Super Moderators (Glyn, RWD) whom passed along their expertise.

Tip: It very well could be the timing chain. Apparently the M271 on the C230K has a single link chain that stretches over time. It's a highly stressed engine and should be a recommended service by MB... Another symptom would be, like you said, the cams.

https://mbworld.org/forums/c-class-w...hain-help.html

I don't feel like such a "Noob" anymore. Haha

Pauliescff

I found the answer. Spoke with a friend who is a service manager at the local dealership.

VVF

Why not post the answer here and potentially help fellow owners out?

Norsk_Johnson

I agree. What was the outcome?

MattsC230

I also have a 05' C230. I have about 69,000 miles as well. I run the same oil. And vehicle runs smoothly. The same noise occurs during cold or warm startup. I suggest maybe a new timing chain and running an OEM oil filter.

Pauliescff

Ok. I think I'll give that a try

Pauliescff

Sorry folks. What he said was that it is possible for the timing chain to be making noise, but not likely. He said the hydraulic chain tensioners are problematic and to replace that. He also said to ensure using Mercedes filters as aftermarket have been known to cause oil pressure problems. Lastly, he said to go up to the next grade of oil. This is coming from the shop foreman at the local Mercedes dealer.

Norsk_Johnson

Good to know. What oil are you using now? I went from Mobil 1 Euro 0W-40 to Pennzoil Pure Plus Euro 5W-40, both being 229.5 approved. In addition, I'm using a Hengst Oil OEM Oil filter.

Oil: https://www.amazon.com/dp/B00JMCCBRW..._SSH.vbMTDZAY1

Filter: https://www.amazon.com/dp/B002WSX6W2..._DRH.vbHGQNSBR

Pauliescff

I haven't done anything yet. Just got the filter and the tensioner. Going to go with 5w-40 as well. With that said, has anyone on here replaced the timing chain tensioner? If so, is there any special procedure to follow? After all is complete, I'll report any changes.

RWDlifer

The tensioner is an easy remove and replace, but you have to remove the alternator. Additionally, there is a one time use plug covering the tensioner, ie you'll have to destroy it to remove it. It will be visible once you have the alternator out.
That being said, a word of caution: with the tensioner removed, the slack in the chain could cause it to skip teeth and throw the timing off. I would recommend setting the engine to TDC and removing the valve cover to reference the timing marks.

Pauliescff

Has anyone experienced this noise due to faulty camshaft adjuster magnets? I disconnected both of them and the noise seems to have gone away. Would this be the magnets or the actual cam adjuster assembly?

VVF

Likely the adjusters. They need oil pressure for correct operation.

RWDlifer

The magnets themselves are not the problem, they were one of the first things I replaced when I got my car. It's the variable timing adjusters on the camshafts that rattle. Some people have had luck having them replaced by MB cost free or deeply discounted. Disconnecting the magnets changes how the adjusters behave, but it's not a fix...plus, you'll end up with a CEL and likely affect the car's performance.
Also, the noise could be belt slap...check the alternator pulley to make sure it's not siezed...
Watch this vid, the alternator on our cars is exactly the same...helped me a lot and I discovered a seized pulley before things got too bad.

Pauliescff

I already had the alternator pulley replaced a while back because it had seized. I'm convinced it's the actual cam adjuster units as the noise didn't occur with the magnets disconnected. After I reconnected them, the noise returned.

Pauliescff

This should be video of a cold start with the noise immediately after starting. Only lasted for less than a second. Sometimes it lasts for up ton2 seconds and it doesn't always do it. Sometimes it does it hot, cold, or not at all. Thoughts?

Pauliescff

http://www.youtube.com/watch?v=EOyGqkwN2Z0&sns=em

Norsk_Johnson

Video is private, can't view it. Enter it as a link as well, so ppl can press and go, if you can.

Pauliescff

Try the one below

Pauliescff

http://youtu.be/EOyGqkwN2Z0

Norsk_Johnson

Yeah, sounds like mine. I will say, I can't hear it quite as well 'cause your camera is in the car. I'd suggest taking one outside, hold the phone outside your window while starting. Or open the hood, leave your phone in the engine bay and start the car while recording - that's what I did.

My guess, it's the cam adjusters just like RWDlifer said. Hell, mine does it even when it's warm, hot, cold too. It does it worse when it's been parked on a decline. And goes away if I rev the engine real good before turning off and parking it. Idk. I think it's just the nature of the M271 brother.

Pauliescff

That video was actual outside the car on the windshield. The noise just wasn't as loud or long this go around. Perhaps when parked on an incline, with the rear lower than the front; the oil drains away from the adjusters? Thanks for your reply..