Spark Plugs - 2015 GLK 350
Do you mean to replace the brake fluid?
ABS must be activated or fluid will now flush through it. When systems fail on a mb they cost more than many other cars to fix ! New fluids protect what you have.
QUOTE=Mmr1;8998115]If it runs smooth , since it’s a new vehicle to you , and you don’t know if it was maintained, which it probably was not , then Motor oil, Brake fluid, Antifreeze, and the transmission would be my first thing I would do. Brake fluid goes bad from moisture, you will notice better braking with new fluid. The ABS must be activated or fluid will now flush through it. When systems fail on a mb they cost more than many other cars to fix ! New fluids protect what you have.[/QUOTE]




I look up parts diagrams based on my submodel, I have the 204.081 for example. You can find your specific submodel by looking up your vin #, thats why they ask for your vin# so they can look up your specific parts.
I search around for parts diagrams and maintenance procedures, then when I come across them I will save them to my computer and even print it out. I have a binder full of almost all my cars parts diagrams.
Here is where I get my parts diagrams for my W204, it has the X204 also: https://nemigaparts.com/cat_spares/epc/mercedes/1/204/
Heres the spark plug change procedure for mine, its pretty basic. I should just buy the wis but I have had good luck finding everything I need so far online. Can find anything with enough searching.




I look up parts diagrams based on my submodel, I have the 204.081 for example. You can find your specific submodel by looking up your vin #, thats why they ask for your vin# so they can look up your specific parts.
I search around for parts diagrams and maintenance procedures, then when I come across them I will save them to my computer and even print it out. I have a binder full of almost all my cars parts diagrams.
Here is where I get my parts diagrams for my W204, it has the X204 also: https://nemigaparts.com/cat_spares/epc/mercedes/1/204/
Heres the spark plug change procedure for mine, its pretty basic. I should just buy the wis but I have had good luck finding everything I need so far online. Can find anything with enough searching.
I saw that earlier, but I was unsure about it because it did not say GLK 350; now I know that multiple models have the M276, and the work is similar!
Thanks again.




The Best of Mercedes & AMG




Can you give me the link?
The information you provided matches many sources I found online.
Below is the info afound online.Spark plugs are tightened to 23Nm and gap is 0.8mm
Ignition coil bolts are tightened to 9Nm




I was planning to add anti-seize as I do with BMW motorcycles.
Even when we try hard to do the job correctly, we still do it wrong; what can I say, maybe there is a margin of error that the builders add to the technical specifications.
May the specifications range from 20 Nm to 25 Nm? I can't imagine all the torque wrenches being exact or equal.
I'm sure some people here still use their 20-year-old toque wrench that was never calibrated. Some people said I should go 1/4 turn after I hear the click.
And if I add anti-seize, that could be 27Nm; if you take 30%, make it 25nm. I was planning on paying $145 for a Wera torque wrench, but I think I will keep using the bicycle torque wrench I bought for my carbon fiber bike!
He also told me that the spark plugs last 100K and that I did not need to change them right now. He also mentioned that the transmission filter can be reused depending on whether the transmission fluid is clean.
He said that he only uses Mercedes parts and fluids. Many of us have had bad experiences when we go to the mechanic; they try to replace every part they can to make the most money.
The cost of transmission service, brake fluid change, transfer case, and differential service will cost me what the Mercedes dealers charge only for the transmission service.
I was planning to add anti-seize as I do with BMW motorcycles.
Even when we try hard to do the job correctly, we still do it wrong; what can I say, maybe there is a margin of error that the builders add to the technical specifications.
May the specifications range from 20 Nm to 25 Nm? I can't imagine all the torque wrenches being exact or equal.
I'm sure some people here still use their 20-year-old toque wrench that was never calibrated. Some people said I should go 1/4 turn after I hear the click.
And if I add anti-seize, that could be 27Nm; if you take 30%, make it 25nm. I was planning on paying $145 for a Wera torque wrench, but I think I will keep using the bicycle torque wrench I bought for my carbon fiber bike!
I'm certainly not saying you should not use anti-seize on the spark plug threads. Just saying you should compensate for such use if it's not specified by M-B. With the difficulty involved getting to the GLK spark plugs and the amount of time they stay in, because of how long they last, I would be much more interested in using anti-seize on the GLK rather than on motorcycle plugs. With the motorcycle plugs you can get to them much more easily and if you just loosened them, examined them and re-tightened once a year you would probably be fine with no anti-seize.
May the specifications range from 20 Nm to 25 Nm? I can't imagine all the torque wrenches being exact or equal.
I'm sure some people here still use their 20-year-old toque wrench that was never calibrated. Some people said I should go 1/4 turn after I hear the click.
And if I add anti-seize, that could be 27Nm; if you take 30%, make it 25nm. I was planning on paying $145 for a Wera torque wrench, but I think I will keep using the bicycle torque wrench I bought for my carbon fiber bike!
Going an additional 1/4 turn after the click is nonsense. That's an additional 90 degrees which is not insignificant. There are applications and fasteners that are to be tightened to a certain value with a torque wrench and then turned an additional "X" number of degrees. When this is the case the manufacturer of the engine or other machine clearly lets you know in their technical literature.
I would put more faith in a 20 year old, quality torque wrench that has never even been re-calibrated (such as Wera, Hazet, Snap-On, Stahlwille, Facom etc.) than I would in a brand new cheap torque wrench. What John CC wrote about getting a low-end torque wrench tested/calibrated is a perfect example. It must first be a consistent wrench. The torque setting may be off but if it's still in the window of adjustability it can be set accurately. You have to have the repeatability. That's the starting point. Having said that, even good wrenches won't be ideal if they're stored poorly and handled/used poorly or just generally thrown around.
No matter what you are tightening the general rule is you want a torque wrench with a range thats in the middle of the tightening torque. If you need to tighten to 23Nm a torque wrench that adjusts from say 16Nm to 30Nm would be ideal-ish as 23Nm would be mid-scale. The reality is, of course, people don't buy a torque wrench for every different torque setting. You have to compromise, but wisely.
Last edited by MBKLUE; Jul 9, 2024 at 08:28 AM.
While not an indicator of coolant quality, you should also check the specific gravity of the coolant to make sure it's at the correct ratio for your environment.




I'm not sure about the M276 but I have read certain engines need to have the spark plugs properly indexed, oriented in a specific position.
I thought I had read, long ago, the M276 plugs need to be indexed but I haven't seen any mention of it here. Maybe I was thinking of a different engine.
Last edited by MBKLUE; Jul 9, 2024 at 10:53 AM.
I should be able to replace the coolant myself...Can I use any band of coolant on the GLK350, or just factory?
You can't go wrong with coolant from the M-B but you'll pay a premium. Good thing it doesn't have to be changed often. There seem to be a lot of different formulas out there but I'm sure there must be brands that have an equivalent version. I'm sure M-B do not make their own coolant :-)
I believe you must not make your selection based on the color, alone, of the coolant matching the color used for your vehicle from the factory.
Don't know which other(s) are suitable but no doubt some other folks on here do.
Last edited by MBKLUE; Jul 12, 2024 at 02:54 AM.
Last edited by Mmr1; Jul 12, 2024 at 07:15 AM.




- Zerex G48 MB 325.0
- Zerex G40 MB 325.5/ MB 325.6/ MB 326.0
I use the 50/50 pre-mixed which says it uses demineralized water. I replaced the coolant last year when I was replacing the oil filter housing gaskets. It was easy. The old coolant looked in really good condition so i didnt bother flushing, just drained and re-filled. Pour the coolant in the reservoir until full, start the car then keep adding coolant until its topped off. I did have to top it off in the following day or two, guessing all the air was being purged.
Local Napa autoparts had it on sale at the time. I bought two jugs and ended up having a quart or two left over.
Mercedes-Benz has only used two different types of coolants in their cars, SUVs, and vans. A blue or pink-violet color coolant. Up to the manufacture date of April 2014 most Mercedes-Benz engines used the blue MB 325.0 and MB 326.0 specification coolant. After April of 2014, Mercedes started using the pink-violet MB 325.5 MB 325.6 coolant specification.
- Zerex G48 MB 325.0
- Zerex G40 MB 325.5/ MB 325.6/ MB 326.0
I use the 50/50 pre-mixed which says it uses demineralized water. I replaced the coolant last year when I was replacing the oil filter housing gaskets. It was easy. The old coolant looked in really good condition so i didnt bother flushing, just drained and re-filled. Pour the coolant in the reservoir until full, start the car then keep adding coolant until its topped off. I did have to top it off in the following day or two, guessing all the air was being purged.
Local Napa autoparts had it on sale at the time. I bought two jugs and ended up having a quart or two left over.






