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I have a 2008 C300 4Matic. It has nearly 179k miles and I’m looking to keep this running great for many more years to come. I did Mobil 1 OW-40 for my last change, and I’ve used Mobil 1 nearly exclusively for every vehicle I’ve owned. However, I feel the 0W-40 really made my engine much louder, and I’ve seen some people mention that they burn much more oil running that. I live up north, so I used the thinner oil for startups but I have used vehicles that required 15W-40 in the past and never had any real issues with starting, so I’m definitely going to 5W-40 for this next change.
My real question is, should I run the genuine oil, or Liqui Moly Leichtlauf 5W-40? I know MB doesn’t actually make any oil, but again I read some people actually burned less oil with the genuine than the LM oil. I’m looking to change my oil soon so I can change the oil cooler gasket as well. I have power steering fluid ordered, 2 concentrated gallons of Zerez G05 (4 diluted), and just need to decide what oil I want to use and then I’m ready for the job.
Thank you all in advance! Sorry for another oil thread, but I couldn’t find one specifically about these two being compared.
Liquid Moly, period. Plus, at higher milage a heavier weight
The 0W-40 hasn’t burned a drop seemingly in 3k miles, so thankfully oil burning doesn’t seem to be an issue. On another note, any opinions on Ceratec? Debating on if I want to add 2 bottles of that to my next oil change as well.
Zerex G05? Is that what it calls for? I only ask because my 2010 4matic M272 engine uses the G48. Its the blue/green color. When I replaced the oil filter housing gasket/oil cooler gasket I bought two jugs of the G48 50/50 pre-mixed and had some left over.
Zerex G05? Is that what it calls for? I only ask because my 2010 4matic M272 engine uses the G48. Its the blue/green color. When I replaced the oil filter housing gasket/oil cooler gasket I bought two jugs of the G48 50/50 pre-mixed and had some left over.
What’s in my engine right now is a blueish green as well, but when I was searching online it said that 2008 model year in the US used G05 coolant from factory. I haven’t cracked open the current bottles I bought to see what color they are. Should I go exchange for G48? I am a regular at my local advance auto and they’ll definitely let me exchange them without a hassle of getting refunded and having to buy again.
Zerex G05? Is that what it calls for? I only ask because my 2010 4matic M272 engine uses the G48. Its the blue/green color. When I replaced the oil filter housing gasket/oil cooler gasket I bought two jugs of the G48 50/50 pre-mixed and had some left over.
Nevermind, i see it at the bottom.
I see you updated your post since I replied, but I might go exchange for G48 anyway. What’s in there already is definitely that same color, and it seems G05 is a gold color from my quick research. I’ll have to fix that tomorrow, and good to know about how much coolant you used as well. I may return one of my bottles as well.
I looked it up on the Zerex website and plugged in 2008 C300 3.0 and it shows "Does not fit". Mine is a 2010 with the M272 and the blue/green was in there and I used the G48. When I had my car worked on recently at the MB dealer they billed me for Zerex G48 coolant.
I did not drain the entire cooling system when I did the gaskets. I didnt even touch the drain at the bottom of the radiator. I simply removed the thermostat out of the way then removed the oil filter housing from the engine. I just let the coolant flow out. Then with the oil filter housing off I replaced the oil cooler gasket. I wasnt sure where the leak was coming from so I changed both gaskets. I made a thread with all the parts i used, tools and torque specs. It turned out to be pretty simple.
My car had over 150,000 miles so the manual says the coolant needed to be changed anyways. The old coolant looked to be in great condition so I wasnt worried about not completely draining it all out.
I searched around for the thread I made showing the oil filter housing replacement. Now i remember where I got the Zerex G48 from, right from the MB bevo website. I dont think ive even heard of the G05 before today.
The only reason i changed the oil was I wanted to drain it in case any coolant had dripped in while the oil filter housing was off. The oil looked great so I dont think any did. Since i removed the thermostat I replaced the thermostat housing gasket and the o-ring type gasket on the thermostat. The the oil filter housing gasket and the oil cooler gasket.
What is strange is in the back of my operators manual it says the coolant system holds 4.8 liters but I must have put around 6 liters back in. And thats me not even draining the radiator.
My real question is, should I run the genuine oil, or Liqui Moly Leichtlauf 5W-40?
Insider info: There is absolutely nothing special about Mercedes genuine engine oil. During the “Mercedes Recommends Mobil 1” era that’s what was in the Mercedes bottles. After that campaign expired, the Mercedes genuine oil was supplied by Petronas, who, wait for it…, used ExxonMobil processes to make their lubricants. I don’t know what’s currently in the genuine bottles, but it’s not going to be anything you can’t get elsewhere. Liqui Moly labeled for 229.5 is fine.
As for 0W-40 running noisy, we had that issue when we had BMWs in the mix. They even used about 1/2 quart between changes. We switched them to Castrol Euro 5W-40. Noise and consumption went away.
I searched around for the thread I made showing the oil filter housing replacement. Now i remember where I got the Zerex G48 from, right from the MB bevo website. I dont think ive even heard of the G05 before today.
The only reason i changed the oil was I wanted to drain it in case any coolant had dripped in while the oil filter housing was off. The oil looked great so I dont think any did. Since i removed the thermostat I replaced the thermostat housing gasket and the o-ring type gasket on the thermostat. The the oil filter housing gasket and the oil cooler gasket.
What is strange is in the back of my operators manual it says the coolant system holds 4.8 liters but I must have put around 6 liters back in. And thats me not even draining the radiator.
That’s strange. A google search of mine showed exactly double that as the capacity. 9.6 liters was shown as the full capacity when I googled it lol. I do plan on draining the radiator as well, so I’ll probably hang on to the extra gallon actually.
I have been toying with the idea of replacing the oil filter housing gasket, oil cooler gasket, and coolant expansion tank all in that same job as well. My dash shows “check coolant level” periodically and completely randomly. I believe the sensor is on its way out and throws the code once in a while. And no, the level isn’t low. I filled the reservoir to the brim and let it bleed out whatever wasn’t necessary as a test to confirm, and it still threw the code a few days later, it was still full.
While we’re on the topic of coolant as well, does anyone know if it’s normal for the coolant hoses (all of them) to feel thinner than other manufacturers do? This is my first Mercedes, and every other car I’ve ever had before had some fairly firm radiator hoses all around. I noticed that all of mine feel rather thin and are easy to squeeze, but they’re all exactly the same feeling. Unsure if I should replace them all or if MB just uses a more flexible material than I’m used to.
Last edited by hmclaughlin67; Jan 6, 2025 at 01:02 AM.
Honestly its all good. LM in their home country isn't the price it is here. Mobil 1 is inexpensive because it's produced here domestically using the European formula that was once only made over there. If you notice more noise with 0w40, on cold start, you can switch to Castrol's 5w40, or I have an Amsoil 5w40 European that would serve you very well.
Originally Posted by hmclaughlin67
That’s strange. A google search of mine showed exactly double that as the capacity. 9.6 liters was shown as the full capacity when I googled it lol. I do plan on draining the radiator as well, so I’ll probably hang on to the extra gallon actually.
I have been toying with the idea of replacing the oil filter housing gasket, oil cooler gasket, and coolant expansion tank all in that same job as well. My dash shows “check coolant level” periodically and completely randomly. I believe the sensor is on its way out and throws the code once in a while. And no, the level isn’t low. I filled the reservoir to the brim and let it bleed out whatever wasn’t necessary as a test to confirm, and it still threw the code a few days later, it was still full.
While we’re on the topic of coolant as well, does anyone know if it’s normal for the coolant hoses (all of them) to feel thinner than other manufacturers do? This is my first Mercedes, and every other car I’ve ever had before had some fairly firm radiator hoses all around. I noticed that all of mine feel rather thin and are easy to squeeze, but they’re all exactly the same feeling. Unsure if I should replace them all or if MB just uses a more flexible material than I’m used to.
Also its never completely empty. Some oil sits in the cooler, and the bottom edges of the pan.
Check coolant level is because the sensor is RIGHT there at the halfway mark so if you slosh it around it can think its empty when its really not. Whats funny is the fill level mark is up to slightly past the sensor anyway. You'll know when the sensor is going out because itll start leaking and itl fail electronically. MB hoses probably just feel different to you. They last a really long time though. I've never had to replace a hose on anything so far. If you need some stuff to replace right now, you probaly have the PCV cover thing on the back that is leaking, the cam caps, and that big 65mm cap on the right side. Inspect your cam magnets and sensors and buy an 8mm wrench so you can tackle them without removing the power steering reservoir on the right side.
The oil cooler gasket/oil housing gasket should be done with like the belt/tensioner/pulleys IMO, so this might be a great opportunity for you to get a lot done.
Honestly its all good. LM in their home country isn't the price it is here. Mobil 1 is inexpensive because it's produced here domestically using the European formula that was once only made over there. If you notice more noise with 0w40, on cold start, you can switch to Castrol's 5w40, or I have an Amsoil 5w40 European that would serve you very well.
Also its never completely empty. Some oil sits in the cooler, and the bottom edges of the pan.
Check coolant level is because the sensor is RIGHT there at the halfway mark so if you slosh it around it can think its empty when its really not. Whats funny is the fill level mark is up to slightly past the sensor anyway. You'll know when the sensor is going out because itll start leaking and itl fail electronically. MB hoses probably just feel different to you. They last a really long time though. I've never had to replace a hose on anything so far. If you need some stuff to replace right now, you probaly have the PCV cover thing on the back that is leaking, the cam caps, and that big 65mm cap on the right side. Inspect your cam magnets and sensors and buy an 8mm wrench so you can tackle them without removing the power steering reservoir on the right side.
The oil cooler gasket/oil housing gasket should be done with like the belt/tensioner/pulleys IMO, so this might be a great opportunity for you to get a lot done.
I’m in the US, so my engine is equipped with a vacuum pump there instead of the 65mm plug. As for the sensor on the expansion tank, I know it can be iffy with the level, but that’s why I filled it right to the very top of the tank too. I filled it all the way to the cap since the cap will bleed off whatever fluid is too much. So there’s no way for it to be sloshing around, but I still got the code after a while. I then checked the tank once then coolant was cold and it was still completely full. I hope that explanation makes sense.
As for everything else you mentioned, I actually already did all of those, including the oil drain pan behind that centrifuge cover on the rear of the engine. The only one you’ve mentioned that I haven’t done is cam magnets. What should I look for symptom wise to know if they’re failing? I’ve been doing a lot of maintenance to the car, hence all the questions I’ve had lol.
Do you have the additional harnesses for the cam adjusters? I think if they were failing you would either see oil leaking from them and/or check engine light.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by hmclaughlin67
The 0W-40 hasn’t burned a drop seemingly in 3k miles, so thankfully oil burning doesn’t seem to be an issue. On another note, any opinions on Ceratec? Debating on if I want to add 2 bottles of that to my next oil change as well.
There will be a lot of opinions, but any oil additive should be avoided if you are using a high-quality oil to begin with. I tried it but immediately changed my oil after watching a video by The Motor Oil Geek concerning additives.
If any of these additives are magic potions, the oil manufacturers are already putting the same ingredients into their oil blends. Some people shake tabasco onto everything they eat too.
I’m in the US, so my engine is equipped with a vacuum pump there instead of the 65mm plug. As for the sensor on the expansion tank, I know it can be iffy with the level, but that’s why I filled it right to the very top of the tank too. I filled it all the way to the cap since the cap will bleed off whatever fluid is too much. So there’s no way for it to be sloshing around, but I still got the code after a while. I then checked the tank once then coolant was cold and it was still completely full. I hope that explanation makes sense.
As for everything else you mentioned, I actually already did all of those, including the oil drain pan behind that centrifuge cover on the rear of the engine. The only one you’ve mentioned that I haven’t done is cam magnets. What should I look for symptom wise to know if they’re failing? I’ve been doing a lot of maintenance to the car, hence all the questions I’ve had lol.
youll know, there will be oil everywhere on your front timing cover.. it's not a subtle leak its pretty rapid since the o-rings are tiny.
Its the lil plastic connectors on the front of the camshaft area... basically the magnets that monitor camshaft deviation and you get the position sensors above them. They have these o-rings that leak, its like the only thing that sucks on Mercedes cars, but from what I understand you can drive a car for YEARS this way without even knowing it. Uhh the fix is pretty easy you just replace either the o-ring or the whole assembly. O-rings are like $4 for the Elring part.
youll know, there will be oil everywhere on your front timing cover.. it's not a subtle leak its pretty rapid since the o-rings are tiny.
Its the lil plastic connectors on the front of the camshaft area... basically the magnets that monitor camshaft deviation and you get the position sensors above them. They have these o-rings that leak, its like the only thing that sucks on Mercedes cars, but from what I understand you can drive a car for YEARS this way without even knowing it. Uhh the fix is pretty easy you just replace either the o-ring or the whole assembly. O-rings are like $4 for the Elring part.
Yeah it sounds like your sensor is going out, I'd replace the tank, cap, and sensor in that case.
My understanding is that the sensor is built in to the tank, is that correct? I ordered a new cap and am holding off on the reservoir for now while I research more. If I need to order the sensor too then I will but I want to confirm that they’re on piece.
Looks built-in to me. Im not seeing a separate part # for the level sensor, just shows the tank then the connector for the sensor.
My Audi had the same issue with my coolant tank. Was saying level was low but it fine. Sensor was built into the tank. The sensor gets gunked up or corroded.
I wonder how the sensor works, is it a float type sensor? Someone should cut the reservoir open if they replace it to see what it looks like in there.
If the sensor is going off may check the connector for any corrosion. I was searching around to see what the sensor looks like and came across some photos of other Mercedes in general where the plug was corroded and needed to be cleaned off.. Looked like most of those were leaking so had to replace the reservoir anyways.
I work on multiple makes, Porsche's is a sealing sensor for some reason so it develops leaks and goes out.. same logic would apply here though yeah. Honestly there are pretty inexpensive fixes, the URO tank has worked in a pinch for me
I wonder how the sensor works, is it a float type sensor? Someone should cut the reservoir open if they replace it to see what it looks like in there.
If the sensor is going off may check the connector for any corrosion. I was searching around to see what the sensor looks like and came across some photos of other Mercedes in general where the plug was corroded and needed to be cleaned off.. Looked like most of those were leaking so had to replace the reservoir anyways.
I ordered a new reservoir last night. When I replace mine, I will cut it open and try my best to show you all how it works. I’ve been wondering myself, and I think that a float sensor makes the most sense. I ordered from 3 different websites for the best prices on everything I needed, so once it all arrives I will be tackling the project.
We're talking about the coolant level sensor here? (The opening thread was about oil.) My coolant level sensor is a simple 2-electrode arrangement that uses the coolant's electric conductivity -- no moving parts. But it's possible that electrodes could develop corrosion and malfunction (although I would think coolant corrosion inhibitors would prevent this).
We're talking about the coolant level sensor here? (The opening thread was about oil.) My coolant level sensor is a simple 2-electrode arrangement that uses the coolant's electric conductivity -- no moving parts. But it's possible that electrodes could develop corrosion and malfunction (although I would think coolant corrosion inhibitors would prevent this).
We got a little off track, lol. My original question was answered quickly and then found out I bought the wrong coolant so here we are. And that’s interesting, mine is (I believe) beginning to fail. I wonder where it has failed in that case.
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