NolaGL550

My GL550 is making a small rattling sound at cold startup that lasts about 2 to 5 seconds, then I don't hear it anymore. When having other repairs performed at the local dealership, they said this is common to GLs with the M278 engine, and that the Technical Bulletin LI05.10-P-056435 states replacing the timing chain tensioners on each bank of cylinders will remedy the issue. The TB also dictates they install a "check valve" in each oiling port on the head; right behind the timing chain tensioners. Their estimated cost with labor is $1670. I've tried to get two indy shops to give me an estimate, but neither have replied back after over two weeks. I'm tempted to just let the dealership perform the work, but I don't want to overpay as I'm sure they will mark up parts cost and have an exorbitant labor rate compared to the indy shops. I also have toyed with doing this myself since I found a Mercedes technician training video that walks through the entire process. However, I'm certain this would void my extended warranty if I performed it personally. Anyone have this TB based repair performed on their GL, how much did you pay, and did it remedy the issue? Thanks in advance!

fabbrisd1

If you don't mind me asking - if you have Extended Warranty - why wouldn't this be covered ?

black06c230

Agree if you have a warrant have them foot the bull a snap just pay the deductible. Ours is currently in Shop for the same thing and should be back next week. Only out $200 on deductible.

mtm

I had this done on my 2013 GL450, but it was under warranty, so don't know the cost. Given that it's a well-known issue and that there is a TSB on it, I'd ask the dealer to work with MB USA to cover at least part of the cost.

NolaGL550

I bought an extended warranty though a third party company called Endurance, but they actually are only the broker of the warranty. They actually sell it to another warranty company, in my case Interstate National Dealer Service, Inc., and that's how they get you. My service advisor actually called the number to get my repair authorized, and they immediately declined to cover the service. I'm in the process of dropping this warranty and using another company that was referred by a reputable indy shop owner. We'll see how it all works out, but I'm sure I'll be footing the bill on this repair.

NolaGL550

Is your extended warranty through Mercedes, or did you get one through a third party company?

NolaGL550

I will talk with my service advisor to see if they'll work with me on this repair. Did your service advisor contact MB directly, or did you have to talk with MB before the dealer would perform the repair for free or discounted cost?

mtm

My service advisor handled everything, but that was when the car had 20K miles and was still under warranty. I did show him the TSB so he knew what the problem was.

NolaGL550

That would be the ideal situation, but I'm afraid having a third party warranty changes things. I'm in the process of allowing my indy shop near home do some legwork and attempt to get the warranty company to cover at least the non-return (check) valves. If they can't get it covered, I'm doing it myself. I've read the Service Bulletin and researched the parts, plus watched several MB Tech videos in order to assess the difficulty of the repair. For a total of $175 for the specialty tool, and $33 for the non-return (check) valves, I can perform it myself and save thousands of dollars. Lucky for me, my engine number falls in the range that were given the upgraded secondary timing tensioners, so I just need the non-return (check) valves installed. Here's the link to the appropriate valves for M278 Engine equipped GL with the larger oil ports on the heads: https://www.genuinemercedesparts.com...lve-2780503300

black06c230

Here is the repair order for the guides, $15xx and warranty deductible for me was $200.

NolaGL550

I truly appreciate you posting this. It's very close to the repair estimate I received from my dealership. However, I wonder why they installed three non-return (check) valves? I'll have to research a bit more about this repair on the M278 engines because I was under the impression that certain oiling ports took a larger diameter or smaller diameter check valve. Glad to know your warranty covered everything after the deductible was paid. If I do this repair myself, I'll be in at approximately $23 total since I just need to install the check valves and already have MB sealant for the timing chain access covers. I may just perform this myself. If I do, I'll take a ton of pictures and list the parts I use. Gotta help the next guy down the line. Thanks again for sharing your repair bill!

NolaGL550

I think I figured out the reason your parts list for the repair was larger than mine. I have a 2013 M278 equipped GL, and yours is a 2005 E55 with the M278. They likely use different oiling port sizes on the heads, plus different timing tensioners.

BlownV8

The E55 used the M113k.

ItalianJoe1

There's only two valves per engine, but there are two different parts depending on which size bore is in the head. That estimate looks like they quoted both and just didn't remove them.

We normally grab all 4 and then just install the right ones when we remove the tensioners and know which ones we need, then give the other ones back to the parts dept.

black06c230

No we own a 2013 GL550 with a M278, my sig is of my E55 which as stated has a M113k.

NolaGL550

Ah, that makes sense. I ordered the check valves via the part number stated on the Service Bulletin for the repair under M278 engines in my engine number segment. I hope they are correct since disassembly will have my vehicle down for a day as I replace the timing tensioners and install the check valves. So, on an M278 equipped GL, how much of the intake/turbo piping do you have to remove to access the front timing covers on the heads? I did a preliminary look yesterday and it appears that there is quite a bit of disassembly required to gain access. After that, it seems pretty straightforward. Also, how do you align the timing chain marks with the engine in the vehicle before removing the tensioners? If you have a link to the full Mercedes guided repair, can you share it? Thanks for the response, by the way!

NolaGL550

I was just confused by the sig. Thanks for sharing the repair estimate for your GL550. It definitely helped me decide with parts to order to ensure correctness along with the Service Bulletin related to the issue. I ordered everything on October 11th, but have to wait until the special tool to install the check valves comes to the States from Germany. Should be a few more days before it arrives to complete the order. Once I get everything, I'll post the full install plus some pictures on the forum. If it goes relatively easily, I may market myself as someone in the area willing to be a "shadetree mechanic" for this repair on local owner's GLs.

ItalianJoe1

The air pipes have to come off but they are simple, although they will be stuck in there pretty good usually.

The timing mark is set by the crank pulley, it's a 27mm socket, you turn it to a certain point for each side, I wanna say +40/-40, but i'd have to look it up. One position keeps the tension off of one specific side, then you turn it and do the other side.

I can't really link the workshop docs, i've tried. I'm sure its out there somewhere though, it's not difficult.

NolaGL550

Thanks for the info, Joe. I was hoping it was a straightforward process. Aligning the crank to take off the tension was my major concern, but it does sound relatively easy.

ItalianJoe1

Yeah the tensioner/check valve repair is nice even in warranty, it pays pretty decent and isn't that bad to do. On the N/A 276 it's very easy as you only have to remove the oil filter and the upper half of the intake manifold, just a couple bolts and you've got the covers exposed.

They use aluminum bolts to hold the covers on, the spec is to replace them every time but in reality you can re-use them, the torque is VERY light, so follow it and use a pattern when going back in, as the bolts snap easily. They are not hard to remove but if you've got the covers all sealed up and on, then have to take them off to remove a bolt that breaks, you gotta clean the sealant and start over.

Ensure the cover mating surfaces are spotless and use the specified sealant and amount, it's a 2mm bead which is very small but it squeezes out too much if you go heavier.

NolaGL550

Almost finished with the right cylinder bank. However, I am not able to find the exact torque specs for the timing chain tensioner bolts. The video tutorial I found on YouTube says the chain cover bolts are 5Nm, and they came of with very little effort on the ratchet. Same for the timing chain tensioner bolts. They came off rather easily, so I'm thinking they are between 5Nm and 10Nm. Anyone have the exact torque requirements?

exhaustgases

This one was a fun read. And the promise of lots of pictures etc. then all the sudden it ends??

NolaGL550

Actually, I was able to successfully replace the timing tensioners and install the check valves per the TSB last November, and have put another 18k miles on the GL since then with no issues or leaks. I have been thinking about posting the tutorial recently, so I may just do that today since I'm still waiting on my NTG 4.5 map V18 update to finish installing in the garage.

The whole process for the rattling timing chain issue was not too difficult. Just a lot of turbo/intercooler piping removal as well as working in tight spaces to remove the torx head bolts off the timing chain covers, then getting the MB sealant and bolts back in was a bear. Getting ahold of the special tool to install the check valves might be the difficult part. Mine was special ordered from Germany by my dealership connection. I'll write up the tutorial soon. Thanks for the interest in the thread.

(p.s. in response to your pre-edit post: I am a bit of a DIY guy, but with a full StarDAS SCN and coding capable programmer/diag machine, access to WIS/ASRA and EPC, tons of MB specific tools, and a mini-shop in my garage. I'm also a previous BMW/Ford/KIA tech and was a Corvette restoration apprentice as my first job out of H.S. So, I'm a slightly above-average DIYer you could say.)

ItalianJoe1

The check valves can be installed with a bolt and nut if you're careful. If you have the proper size thread that will screw into them, then a nut that threads down so you don't bend the pin, and LIGHTLY tap them in with a hammer. We have a special bolt that's bent slightly and works very well to give added clearance lol. It's all in the care you take installing them, as you say, it's not a difficult job, but somewhat time consuming and tedious.

amgboy916

i have m157 but its based off m278 wondering if you can tell me what needs to be removed to check the timing? want to see if it is on mark or off. may have to replace chain and tensioners and add check valve on my car