mogulman

I noticed that the engine makes a ticking/clicking noise on start, when it is cold on my 2013 GLK350 4Matic. It has done this since I got it earlier this year. I did have a dealer service the car since then and they didn't mention anything.

I thought it sounded a little weird, but chalked it up to the car being a Mercedes and I never owned one before. A friend of mine thought it sounded a little strange also. Like valve problems.

It seems to only happen on cold start and then goes away after 10 seconds or so. I can try and make a recording, but wondering if this is unusual?

Maybe it's the oil pressure building or something?

MKenM

If this happens every day you need to bring to the dealer the night before and no have them start it until you arrive. It sounds like a valve/rocker issue. Assuming you have a V-6 try and determine which side of the engine you hear it from. I am also assuming it is the same side each time.

If in fact it is the same side make sure a tech not the tech writer hears it when you start the car. Let us know how you know make out.

mogulman

Here is a link to how it sounds. Seems like some people are saying this is normal for Direct Injection. Some seem to be saying it is related to a TSB...

Here is the link to the TSB:
https://mbworld.org/forums/gl-class-...-start-up.html


Here is the sound of my engine. Kind of hard to hear recorded though.
https://www.dropbox.com/s/t6zivkennz...ing_3.m4a?dl=0

mogulman

I called the dealer. The service advisor told me that it is most likely the Chain tensioners. That it won't hurt anything, but they can look at it.

I'm at 44k Miles right now. So I wanted them to fix it. Leaving it with them in a week while I'm out of town.

Mmr1

I have the same issue, I took it in and they said its normal, but before I took it in their head mechanic said it wasn't normal to hear that type of noise. I think it's an issue they don't want to fix. I also notice my vehicle takes an hour for the oil to go back to full, that's not normal . Maybe it's a new issue coming to light they hope doesn't manifest into a big issue. I have 2013 glk 38000. I think maybe the oil pump drains out

bop11

What do you mean " goes back to full"?

Mmr1

After driving it shows 3/4 a quart low on oil after 10 minutes, it takes an hour to go back to the level it would be at in the morning. It's real level.

Diabolis

The 2013 and later MY GLK350 engines use direct injection and almost sound like diesels. The link you posted (Dropbox) requires a username and password so I can't hear the sound, but it is unlikely that you would have any valvetrain wear issues on a 2013. Are you sure it's not just the injectors?

mogulman

I've been reading some more about it on here. I think I'm going to wait until my next appt to have them look at it. The service rep didn't think it was urgent.

fabbrisd1

For 13's - on select 350 V6 models - there is a TSB regarding diagnosing and replacing malfunctioning chain tensioner.. under warranty

Diabolis

fabbrisd1 is right (thank you!) - in 2012 MB swiched to the M276 motor in the GLK350 from the pre-2012 M272, and some of the early production M276 engines are affected and require updated seconday chain tensioners and oil backflow preventer check valves. The TSB # is LI05.10-P-056435 in STAR XENTRY / DAS . Call your dealership with your VIN and find out if your car has an engine that falls in the affected range. If yes, the fix is documented in the TSB.

fabbrisd1 - thanks again.

Mmr1

Wow oil backflow preventer valve, and I took it in to MB they had it a week and I told them oil level raised up over an hour time period. That sucks that means the motor starts starved of oil!

Mmr1

I've read 50% of engine wear is on startup, if the oil drains back down out of the pump that figure of 50% wear goes way up. I hear excess chatter for about 5 seconds on cold startup, that's how long it would take to re pressurize and push the oil back to the top. I knew something was weird, it should not take nearly an hour for the oil to continue to go up on the dipstick. Even the manual says to only wait 5 minutes. So my actual level is running lower than full because it's nearly at Add after 5 minutes. This is a good way to shorten motor life.

bop11

A typical spin on oil filter on a typical engine holds about a quart of oil. The MB filter looks like it might hold a little less so it appears that your 3/4 of a quart is being used to fill the oil filter. The filter holder has a stem that holds 2, O-rings for sealing the connection to the oil pan. The stem fits into the tube that connects the filter to the pan and holds the non-return valve. The last oil change probably did not change these O-rings and so one is leaking the oil from the filter back down into the oil pan. Either that or the valve in the stem is leaking.
It looks like you start with no oil in the filter. Since the filter should be full when the dip stick reads full, you are running with 3/4 quart low. Worse, since in most engines, the oil filter is after the oil pump but before distribution, if this is the case, you are running without oil in the engine until the filter fills. Does your car show oil pressure on any display?

Mmr1

No pressure gauge, 38000 miles I just got it two months ago. And after sitting 45 minutes I hear chatter for 5 seconds. Thanks for your reply. I'm taking it back soon but already twice they won't address the issue. Thanks again.

Mmr1

Bop11, before I take it back and get told it's ok , can I just take off the filter after sitting an hour, without draining the motor to see if it's empty? Where is the antidrainback valve, is there one in the oil filter or cap? What about the TSB Diablolis mentioned

bop11

When you remove the filter,the whole housing comes out and lets the oil in the filter drain into the oil pan. If you pull it after sitting all night and it looks dry, no dripping, that might tell you it has drained. This is one reason you are suppose to change the filter before draining the oil. If you drain the pan and then pull the filter, you will get another 3/4 to 1 qt of oil coming out.
A dealer or garage with an OBD scanner (pep boys etc.) can plug in and read the oil pressure. Let it sit for an hour or until the dip stick says full, then start it. The oil pressure should come up to at least 40 psi within a few seconds. If it takes a minute or more with the engine only cooled down for an hour, the filter has drained down and the filter housing should be replaced or at least the anti drain down valve.

Mmr1

Thanks I'll try it

Mmr1

Is it simple to remove the filter since you said the whole housing comes out, I was going to try this myself, I never did it on a Mercedes , I've changed oil many times on other cars, is there anything I should be careful of.

Mmr1

I want to try this in a few hours, just take off the filter to check if it has oil in it, and reuse the old filter, is this ok to do? And reuse old gasket so? Thanks

froggy47

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fabbrisd1

Frankly - let the dealer diagnose the tenioner/back-flow - you will need to leave it with them for a overnite sit for proper "cold start" audible diagnosis.

Mmr1

I did, they say it's normal for it to take 45 min to an hour for oil to go back up. I figure I have to prove it at this point. This is aggravating.

fabbrisd1

In your situation - with a copy of your most recent service in hand - with VIN# - date of service - call Mercedes Customer Care (800) 367-6372 and factually explain to them your unresolved problem with that dealer - which starts a 2nd channel from MB to the dealer service management to get this resolved right away. Best to call MB Customer Care in the morning - shortest wait time.

Keep the beat !

bop11

If you remove the housing, you will probably want to replace the o-rings that sometimes come with a new filter. I think there are 3. One at the very bottom, one in the middle and a large one at the top. The filter pulls off as shown below