[NCattorney]

Does anyone have any experience with faulty camshaft adjusters? My wife's C230 Kompressor (2005) has been making a strange rattling sound when started for about 6 months and she recently took it to our local Mercedes dealership. She took it in for the annual service and, upon arriving, found out their was a recall of the camshaft solenoid. The camshaft solenoid was replaced and the dealership determined that the rattling sound was a faulty camshaft adjuster that would take about $3,931 to replace.

Her initial question for the dealership was whether the recalled camshaft solenoid could be responsible for the faulty camshaft adjuster. They told her that they were not related in any way.

This week, we took the car to a local repair shop for them to inspect and give an estimate of the repair costs. They've had the car all week and seem to believe that the Mercedes dealership is wrong about the recalled camshaft solenoid and adjuster being unrelated. Does anyone know where these would be related?

Another strange thing - Immediately after got the car back from the service and inspection the car started sort of shaking and knocking after being started up. It also started making a rattling sound when being driven. This rattling sound is a completely different one that the original. For the past 6 months, the car has done the same thing - make a loud rattling sound for less than 5 seconds when started but that was all (drove normally at all other times). It seems strange that the car took such an extreme turn for the worst immediately after getting it back. This makes me wonder whether the camshaft adjuster is more related to the camshaft solenoid that the dealership initially said.

Can anyone offer any information here? Does anyone know whether the recalled camshaft solenoid would be related to the faulty camshaft adjuster? The repair shop we're getting the quote from still have the car and contacted the Mercedes dealership to get more information about the recall. I'll let you guys know what happens.

Thanks in advance for any help!



Car Specifics:

2005 C230 Kompressor Sport Sedan
W203 C-Class

 

[rudeney]

The adjuster and the solenoid are related, but only because the solenoid is what controls the adjuster. Basically, what you have on the front of each camshaft is a gear that is driven by the timing chain. Without variable valve timing, that gear would simply be forged onto the end of the camshaft and timing would be dictated by that gear's relative position to the crankshaft via teeth on the timing chain.

With the variable valve timing system, the gear is not forged onto the camshaft. Instead, it sits over the end of the camshaft on a bearing so the they can rotate separately. The solenoid bolts onto the gear, and also attaches to the end of the camshaft. So, as the gear is rotated by the timing chain, the solenoid can then control the offset of the camshaft relative to the gear.

The gear itself is called the "adjuster". It can fail either by having its gear teeth wear or break off (very rare) or the bearing between it and the camshaft can fail (probably what has happened). Replacing it requires removing the solenoid and valve cover, releasing tension on the timing chain, and then removing the gear from the camshaft. Special tools and procedures are required to make sure everything is kept in the right position, the timing chain is kept from dropping, etc.

If the bearing is bad, it may have worn the camshaft, so that would need replacing, too. If teeth have broken off of the gear, then they will probably want to remove the timing chain cover and the oil pan to clean out the debris. The camshaft adjuster itself is $850 ($612 at parts.com). The camshaft is $478 ($343 at parts.com).

Here are the parts diagrams from EPC:

M271 Camshaft Parts Diagram
M271 Camshaft Parts List

 

[NCattorney]

The adjuster and the solenoid are related, but only because the solenoid is what controls the adjuster. Basically, what you have on the front of each camshaft is a gear that is driven by the timing chain. Without variable valve timing, that gear would simply be forged onto the end of the camshaft and timing would be dictated by that gear's relative position to the crankshaft via teeth on the timing chain.

With the variable valve timing system, the gear is not forged onto the camshaft. Instead, it sits over the end of the camshaft on a bearing so the they can rotate separately. The solenoid bolts onto the gear, and also attaches to the end of the camshaft. So, as the gear is rotated by the timing chain, the solenoid can then control the offset of the camshaft relative to the gear.

The gear itself is called the "adjuster". It can fail either by having its gear teeth wear or break off (very rare) or the bearing between it and the camshaft can fail (probably what has happened). Replacing it requires removing the solenoid and valve cover, releasing tension on the timing chain, and then removing the gear from the camshaft. Special tools and procedures are required to make sure everything is kept in the right position, the timing chain is kept from dropping, etc.

If the bearing is bad, it may have worn the camshaft, so that would need replacing, too. If teeth have broken off of the gear, then they will probably want to remove the timing chain cover and the oil pan to clean out the debris. The camshaft adjuster itself is $850 ($612 at parts.com). The camshaft is $478 ($343 at parts.com).

Here are the parts diagrams from EPC:

M271 Camshaft Parts Diagram
M271 Camshaft Parts List

Wow! Thanks for the quick response Rudeney! That's a lot of information and I'm going to have to read through it a few more times to process all of it. So, if it is the second situation (bearing between adjuster and the camshaft failed), would that have been caused by the recalled camshaft solenoid? The repair shop seems to think it was and has been looking into it all week.

Also, does the $3,931 quoted price from the dealership seem high? Based on the price of the parts you listed, it seems extremely high. I'm sure, however, the cost of labor and material would be very high as you said the process requires special tools and procedures. Just curious.

Once again, thank you so much for responding so quickly!

 

[rudeney]

So, if it is the second situation (bearing between adjuster and the camshaft failed), would that have been caused by the recalled camshaft solenoid? The repair shop seems to think it was and has been looking into it all week.

I don't see how they could be related unless the mechanic who installed the new solenoid did something incredibly stupid or truly malicious. The solenoid simply attaches the the gear and the camshaft. It's sort of like saying that changing a flat tire caused your transmission to fail.

Also, does the $3,931 quoted price from the dealership seem high? Based on the price of the parts you listed, it seems extremely high. I'm sure, however, the cost of labor and material would be very high as you said the process requires special tools and procedures. Just curious.

Yes, it seems very high. This is all top engine work. Your dealer probably charges $120+/- per hour, so even if they charged you $1000 for parts, that's still over 20 hours of work, and that just doesn't sound right at all.

Once again, thank you so much for responding so quickly!

You're welcome!

 

[NCattorney]

Another quick question - Does it seem strange that the non-dealer service shop we took the car to has had the car for the past week investigating this matter? Sounds like something a professional should be able to determine much quicker. Also, they're charging us almost $100 for the inspection and estimate. Charging for an estimate seemed strange to me but I have virtually no experience in this type of situation. Was initially wondering if they were stalling all week because they had not gotten around to it.


Thanks again for all the help!

 

[rudeney]

Yes, it is customary for shops to charge for diagnostics. They are performing work, using their labor and resources, so they charge. Some shops have a flat rate to diagnose the problem and then apply that to the cost of the repair. Others just charge by the hour. It shouldn't take a week to do this, so yeah, they are probably backed up.

As for your issue, if all the dealer did was replace the solenoid, and now you have new noises, I doubt that is a problem with the camshaft adjuster. The reason is, if it were bad to begin with it would have been making that noise all along. My guess is your original noise was just "valve tap" and it's common on older MBZ engines - you get a little noise at cold startup, then it goes away. Maybe the dealer installed a defective solenoid, or maybe they didn't install it correctly, or they broke something else.

 

[NCattorney]

Quick follow up - This whole thing has taken a strange turn and I'd appreciate your input. After an additional $300 for some band that needed to be replaced, the shop had finished everything and was running tests to make sure everything was ok. The day before we were supposed to pick the car up, they notified us that they needed longer because it was misfiring and they needed to investigate the codes.

Well, the next day we were informed that it was going to be much longer because a valve had bent or something. The problem with the camshaft adjuster was preventing oil was being properly dispersed throughout the engine and when they started running the engine after fixing it a valve bent because the oil hadn't been properly distributed yet. We were told that this problem was a large one and that the car was not drivable at all.

Now, they have had the car for two additional weeks and we have no idea when it is going to be finished. We don't know how much it's going to cost or whether we are going to have to cover the additional costs. Actually, we don't even know the name of the valve that bent or what the process is to replace it. My wife's calling in the morning to find out what the deal is but for the past two weeks we've been in the dark with vague answers.

The shop was very apologetic about everything and offered to personally arrange for a rental car to be delivered to my wife for the duration.

Here are my questions:

• Does this bent valve situation sound like something that is common?
• Any idea how long it takes to fix something like this? Does this seem like an exceptionally long time?
• Any idea how much something like this should cost?
• Does this whole situation sound like some sort of a bait and switch?

Any thoughts?

 

[rudeney]

Valves don't bend because of a lack of oil unless the head is totally dry, and in that case, you'd have worse problems than a single bent valve. Problems with the camshaft adjuster would not cause oiling problems. What can cause a valve to bend is colliding with the piston, and this can only happen if timing is off by enough so that the valve was open while the piston was was moving upward. This could be caused by problems with the camshaft adjuster - either it failing or being improperly installed (i.e. engine timing wasn't set correctly).

 

[NCattorney]

Valves don't bend because of a lack of oil unless the head is totally dry, and in that case, you'd have worse problems than a single bent valve. Problems with the camshaft adjuster would not cause oiling problems. What can cause a valve to bend is colliding with the piston, and this can only happen if timing is off by enough so that the valve was open while the piston was was moving upward. This could be caused by problems with the camshaft adjuster - either it failing or being improperly installed (i.e. engine timing wasn't set correctly).

Thanks for getting back to me again! I suspect that it was an improper installation. We brought in a drivable car, the camshaft adjuster was replaced and they were running "tests to make sure everything was working properly" and then suddenly our car is not drivable at all and additional work is required that is going to take at least three times longer than the original work. That seems like a pretty good indication that they did something very wrong.

My wife exchanged emails with them yesterday and, once again, was not given any details. They said the cylinder was sent to a machine shop and should some back in a few days. Then, after they get it back, they will be able to give us a timeline. Still no details as to what is being done or whether there are additional costs for us. I'm really dreading them coming back after all of this and saying we have to pay an additional thousand dollars or more.

This is exactly why I hate having to deal with anything car related. I know virtually nothing about them and it seems like every time I get anything done I get ripped off. I'm thinking some education is in order.

Thanks again for your insight (and allowing me to vent).

 

[AllWorkNoPlay]

ive had the same problem. its a bolt in from of the camshaft that holds the gears to the cam. thru the center of the bolt there is a valve type deal. almost like a solenoid that allows oil to pass thru it. when that is removed the cam gear also gets removed. if improperly installed and isnt timed properly you can bend or break some valves. do a compression test to confirm any problems and go from there.

 

[AllWorkNoPlay]

i bet the mechanic did the mistake of not timing your car and is trying to redo your valves thats why they sent the head out to the mashine shop.

 

[AllWorkNoPlay]

and dont worry about not knowing information about cars now just continue learning as much as you can about them and thats how you get your experience and knowledge. im in school now for it and its pretty costly. you could of saved a lot of money and done it yourself with some help.

 

[NCattorney]

Thanks for all of the comments! Wish I had good news to report but within 24 hours of finally getting the car back, it is making a loud rattling noise. Anybody have any any clues off the top of their head as to what could be rattling? Sounds like maybe they didn't screw something on very well. I hope it's something that simple. Not excited about taking the car back to this shop but I've over payed so much already, I can't afford to pay someone else to fix the shop's mistakes.

Thanks again for everyone's help!

 

[rudeney]

It could be anything - where is the noise coming from? Does it sounds metallic, plastic, etc.? Does it increase with engine speed or based on gear, A/C use, etc?

 

[AllWorkNoPlay]

is it something specific like everytime you put it in drive and it idles then it makes the rattling noise? and it doesnt when its in the park mode?? hmmm on what side of the car does it rattle? top or bottom? increase the loads on your car by turning on you a/c to see if you can make the noise and turn everything on?

 

[NCattorney]

It could be anything - where is the noise coming from? Does it sounds metallic, plastic, etc.? Does it increase with engine speed or based on gear, A/C use, etc?

The noise is coming from the area around where they would have replaced the camshaft adjuster (according to someone open the hood and help me detect where the noise was coming from). It sounds like a rattling sound. Metallic I think. Also, it isn't effected by accelerating or slowing down.

Sound like anything off the top of your head?

 

[rudeney]

So it's coming from the top front of the engine? And the sounds does not change with engine speed? Hmm, that does not sound like anything related the the cam adjusters. Maybe something just didn't get bolted down tight and it's truly just a rattle that can be easily fixed. At least I hope so! Let us know what it ends up being.

 

[NCattorney]

So it's coming from the top front of the engine? And the sounds does not change with engine speed? Hmm, that does not sound like anything related the the cam adjusters. Maybe something just didn't get bolted down tight and it's truly just a rattle that can be easily fixed. At least I hope so! Let us know what it ends up being.

After another nightmare of an experience and my having to call them out for lying to me, I think I'm picking up the car around lunch time tomorrow. Short version - the rattling was caused by loose bolts below the exhaust.

Supposedly, they found a small oil leak when they had the car lifted and are going to take care of it in the morning. I say "supposedly" because they have been blatantly dishonest throughout this process.

Is leaving bolts loose as much of a sign of incompetence as it seems to me?

 

[rudeney]

Well, leaving a bolt loose is an "honest" mistake, but given all the other issues you've been through, well, I'd say they are pretty incompetent. Also, ask if the oil leak is on the valve covers, and if so, ask if they used genuine MBZ gaskets or aftermarket. If they used aftermarket, that's the reason for the leak - most aftermarket gaskets (especially Victor Reinz brand) are slightly too small and don't fill the slot in the cover and allow oil to leak. They need to use genuine MBZ gaskets (they are about $10 more expensive) or it will continue to leak.

 

[NCattorney]

Well, leaving a bolt loose is an "honest" mistake, but given all the other issues you've been through, well, I'd say they are pretty incompetent. Also, ask if the oil leak is on the valve covers, and if so, ask if they used genuine MBZ gaskets or aftermarket. If they used aftermarket, that's the reason for the leak - most aftermarket gaskets (especially Victor Reinz brand) are slightly too small and don't fill the slot in the cover and allow oil to leak. They need to use genuine MBZ gaskets (they are about $10 more expensive) or it will continue to leak.

They said the oil leak is on part of the brake vacuum pump. They said it was unrelated to any of the work they did and gave a quote to fix it ($400). I told them a quote was not necessary because I would not ever be bringing my car back there.