Hey guys I just got very lucky and got a 2013 C300 for a very good price. It happened to be owned by someone who worked at a dealership for about 8 years and the maintenance was done religiously. The whole thing is immaculate and about as nice as you could have a used car. The second owner was also clean and maintained the condition of this vehicle, so I basically have a creampuff c300 with a 3.5 in it. After finally taking it for a cruise this morning I can finally see how well it is put together and I am amazed. You can really feel the engineering. It's very solid and seems to have the highest level of expectation. I plan on driving it like a grandma everywhere so it stays in good condition.

Questions:

1. It "seems" to be running a bit warm. Not on the gauge but in the actual engine bay. I'm a lube tech so I've been around many vehicles but the Benz seems to be a bit warm. The filter got very hot after a few mile drive. I did just do some research and I saw that the c300 running at 90 is normal which is exactly where it is. My first question was going to be that my "benz temp is a little past the half-way point what do I need to do?", but I guess this is normal. The filter just seemed excessively hot to me.

So I do see some build-up near the upper timing covers. I noticed that when I got it but wasnt sure where it came from. I'm going to get everything out of the way so I can see more but it looks like thats the first thing im going to do with it.
2. I guess I'll replace them with OEM and watch them but does anyone know if there are more resilient pieces to replace the plastic bits within the engine? Some of the pulleys use plastic. I kinda dont like the idea of putting these components that can fail back in the vehicle.
-One thing I will note about this is that it seems somewhat minor. It has 130k miles and there's not really excessive buildup. I guess the dealer owner may have dealt with this and maybe it needs to be readdressed now?

 

What do you mean by "buildup"?

What is a "lube tech"?

 

Jetta, I believe a lube tech is someone either working at a quick change shop (Jiffy Lube, etc), or possibly someone at an indy of some sort who only does oil changes and other smaller jobs of that caliber?

OP, yes these cars (and also BMW if not all German cars) run hotter. More effective for emissions....running hotter & "burning it off" so to speak. You won't see a temp gauge sitting in the middle on these cars, & the temp gauge in the cluster is not indicative of the actual coolant temp. Monitor via OBD with a reliable tool for that.

Can you post pics of this "buildup"? Are you talking about where the timing cover & valve covers meet? M276 timing covers leaking certainly is a thing. It might be more a thing on the 3.0 turbos than your 3.5....it's been a while since I did proper M276 homework.

 

Ok , I do slightly remember trying to grab a Mercedes Benz oil filter and it was very hot, I think the manager even mentioned that the Benz's get hot. Not many really come to the shop understandably so I guess that's why im unfamiliar with the hotter temps.

The woman I bought it from just sold it so cheap it makes me think there's something up with it. The car was kept in 10/10 shape its entire life and she was asking like 2k less than kbb. It has a couple slight gurgles when I first start it but once it gets a little warm that stops. I also did notice I was idling at .5 instead of 1, I don't know if thats also a Mercedes Benz thing or not yet.

Timing cover and valve cover are somewhat minor, I will get pictures later. Thanks guys.

 

I kinda guessed what a lube tech was. Didn't think Lake Speed, Jr. is what he meant.

My 2015 SL400 (M276 3.0l bi-turbo) is much cleaner than my 2014 C350 (M276 3.5l NA). But the SL has less than half the miles (55k) than the C350 (130k).

 

Our moderator and all around W204 knowledge reservoir Glyn M Ruck is a tribologist. But somehow I didn’t equate that with lube tech, although I am kinda fuzzy on the definition. But if a lube tech is the person (they’re not all “guys” anymore) in the pit at Jiffy Lube or Take 5, there is a lot of practical knowledge and experience there.

 

Lake Speed Jr perhaps not, hahaha. Did you have to do any front of engine work on either of your M276's? Forgive my ignorance, but I believe cam adjusters, (more rare?), chain tensioners, and general timing cover leaks are all possibilities on M276's? Perhaps an engine # cutoff as with early M272's and balance shafts regarding the cam adjusters? I'm more familiar with the M272/273 family.

I'd assumed this was the area OP had mentioned. Also, the likelihood of any cam sensors (position or magnet) leaking externally onto the timing covers. I've certainly had a healthy mix of those sensors leaking both externally and electronically.

 

I've enjoyed Glyn's knowledge for years before actually joining this forum. Pretty cool to know of his background.

It's interesting to hear you mention practical knowledge and experience in regards to the people working in the Jiffy Lube pit. I've never been to a "quick lube" place outside of my very 1st or 2nd oil change as a teenager, but you obviously know what the classic sentiment is/was of such places. It would be nice to know that they are not the "bottom of the barrel" they're made out to be. I'm sure there's overqualified techs in those places just as there are underqualified techs in expensive dealerships.