Replacement of Thermostat, Pulley, Belt and Tensioner
 

I've been on a streak of getting things replaced of late and this is my last batch of parts I got replaced this weekend. I had a CEL which I thought was from a purge valve (replaced 2 weeks ago) but it was due to my Thermostat. I noticed over the past month or so, when I would be driving at highway speeds, my temp gauge would lower to about 50 degrees or so. I thought that was odd since why would the car get cooler as I was driving faster and of course a cool breeze from the speed wouldn't make sense either. When I got the purge valve replaced, I was told that my thermostat was bad at that time. This particular Indy that specializes in German Cars has very short Saturday hours 8-12 and only has 2 bays so it's a struggle getting in this particular one but they are probably the best of the Indy's I frequent. I was finally able to get back in this weekend and they ordered the parts for me at the same price I'd get them for and not the dealership marked up pricing.

I noticed a squeaking noise of late and saw that the belt was making the sound as it went on it's loop and it had brown discoloration on a portion of the belt making the sound when it looped. So I called it in and asked if they could have that ready for me as well. Once I arrived and the re-inspected the vehicle a Pulley and Tensioner were advised as well and I was told I have an oil leak that was causing additional wear on the belt (My next fix, I'm guessing). So I got the Thermostat + Coolant, Pulley, Belt, and Tensioner plus labor for $632 after tax and it only took about 1 and a 1/2 hours. Below are the items, I've replaced over the past 2 months. I'm sitting at 144,000 miles roughly and it would've been more but the car was in the shop for about 3 weeks total out of the past couple of months or so. I've driven about 120 miles since Saturday and no CEL has returned yet. I'll update when I look into this oil leak. Oh not to mention I got my Service B at the same time, that I replaced the Purge Valve but they only charge $100 for that. At this point my wife rolls her eyes every time I mention my car LMAO.

Airmatic:
Air Compressor (2X)
Air Filter
2 Rear Bags
Front Right Air Strut (Complete)
Control Valve
Hoses/Lines passenger side

Emissions:
Purge Valve

Engine/Cooling System:
Thermostat
Pulley
Belt
Tensioner

Misc:
Auxiliary Battery
Tire Balance and Alignment
Service B
Driver Side TPMS replacement and reseal of tire (Slow leak)
Replaced Right Side Marker Bulb

Where did u have an oil leak? Was it the seal on oil cooler?
i asked because i saw some oil right under the cooler and also after i put my hand there i could see some oil drops on my gloves.

also replaced my plugs and belt (original was by gates , i got continental elite new one)

and since u mentioned thermostat... did u have any other issues because of that? Anything related to it?

good job on getting all of that done , for a reasonable price as well including parts and labor.. about time with 144k miles.

Used Mercedes are the cheapest cars to drive if you DIY repairs, but can turn very costly when you take them to mechanics.
Sounds like lot of the items have been replaced preemptive, what is understandable as shops like to get all the markups on single job and that also gives better warranty.
Air compressor rebuild kit cost about $15 and it s less than 2 hr DIY (mostly for removal) How much that cost you?

1. I'm actually waiting on a call back from them now. I know he said the leak was from a gasket but I can't remember 100% which one he said. The dealership told me I had a small leak when I got my Service A there quite a few months back but they said it was nothing to rush and fix, so I kinda of let it ride.

2. Nothing of note other then the temp gauge acting odd and the CEL due to bad Thermostat. No noticeable effects on the driving of the car.

Yeah after taking a beating last year (replaced driver side air strut at dealer $1,900) I promised myself I'd get the parts and work with trusted Indy's as much as possible going forward.

Yes, the default on a failing thermostat is to go to full open and then throw the CEL. The CEL may come and go at first and then it goes solid. Mine failed on my 2010 E550 and I replaced all of the same parts as you did.

All parts I noted above I or they ordered OEM except for the Air compressor which I got from Suncore Industries for $269. But I paid next day shipping which cost me an additional $125.82 for a total of $394.82 for the part. Also my Rear Bags I got from BuyAutoParts.com for $102 each with shipping they came to $254. Based on my research and word of mouth these are extremely comparable to Arnott rear bags and they come with a 12 month warranty unlimited miles.

I was thrown off since I was getting an EVAP code on my OBD. I almost discredited the temp gauge as it never went higher then normal but would go lower. I might have jump to quick on replacing the valve but it wasn't to much so I guess it can't hurt plus the code was there for a reason. I was this close to replacing the canister too but that is costly in comparison..

2 rear airbags with shipping for 254? Its a deal of a century right here.
people that actually share their experiences on this forum are priceless. A lot of good info and tips and help.

So far so good with them. Before I replaced some of the airmatic components the car would sit slammed overnight in cold weather. I eventually got a malfuntion alert and it would no longer raise from the slammed position at all after start.

Since the replacements no matter the temp it remains level.

I finally have to replace my last air suspension. Front right finally went out after all others have been replaced over the past 2 years. Looking for good prices without having to send the core out first. I'm coming up with mainly about 900ish just the part which isn't bad. Some places if I send it in 1st will only cost about $500 with shipping included. Just not sure if my go to shop will be able to keep the car up in a bay as they wait for the rebuild. I'll give them a call today to see if they can swing it. Luckily, I have a beater to get me around while the MB is down but I rather get it done this weekend if I can sort through my options. When I got the front left done it was at the dealership and it ran me about $1,900 in total. Either way I'll definitely be saving vs. that.

Couple months ago i also replaced my front right.. i got a used one from car-part.com for 300

Wow 300 is amazing. Let me take a look around and see if I can find something like that. Did you have to send in your core afterward to get the price down that low or this was a str8 up buy used at that price?

exactly what it was , a take off 2011 e550 for a good price.

They are saying $550 and $35 with shipping. I think I'm going to jump on that. Thx

Edit: I just went ahead and got it. Total of $601 with taxes and shipping is a steal. Only downside is standard shipping can take 3-5 business days. Didn't want to justify spending 200 plus for air shipping and still having to wait a day or so anyway.

what was the mileage on the car its coming off from??
lol got to agree wait time sucks

I only asked him was it less the 60,000 miles as the main site says and he said yes. But he never confirmed the exact mileage since I didn't even think to ask that level of detail. I don't see it on the receipt either that they e-mailed so let me check into that. Being that I could've got a brand new one for about double I hope it's not like 80k and they lied Lol.

Update: The bag/suspension I received had a slow leak in it as well, so I'm in the process of sending it back tomorrow morning. I had to replace the compressor again as it failed. I assume it's due to being overworked by the slow leak but it was not even a year old. It's still under warranty so I'm going to try and get it replaced free of charge. Either way I found a used one ($150) in town so I swapped it out and the car rises fine but leaning overnight towards the one leaky bag. I might just let it sit for the next couple of weeks until I get the new bag on so not to overwork the compressor. If I get lucky and get the new one replaced under warranty atleast I'll have two in case one burns out again. I'll update everyone as I get things in order.

The Thermostat failing open is normally the default setting. The logic is 1. won't overheat immediately and hopefully give you a chance to get to the dealer or repair shop, 2. Hopefully make a fairly quick and simple diagnosis.

What you were getting and I would bet almost anything that the code came up as a P0128......Coolant temperature sensor not reading minimum Threshold/outside normal range or something like that. What it is telling you is that the coolant temperature is below the minimum range of the sensor.

EXAMPLE: Coolant temp sensor lets say is programmed to read between 120-260 degrees. As the coolant is passing over the sensor if it too cold to register it will give the fault code. I see your initial post as April 2018 which for most areas would be starting to get warmer but still possible. If the engine is running at highway speeds with ram air over the hood that makes the engine even cooler. Simple version is the Engine is running...TOO COLD...… it can be a common problem especially where the low outside temps, ram air and low CTS reading illuminate the CEL. The P0128 is a fairly standard code among all manufacturers so fairly easy to pull codes from whether it be MB, Audi, BMW, Chev, Dodge, Ford etc... They program thermostats to stick open in that scenario to avoid overheating and engine damage. Yes running prolonged periods even cold can do damage but of the two choices running too cold is less risky.

Good call on the thermostat and other items in that area. With the vehicle being almost 150K miles did you consider the Water Pump at the same time? Doesn't sound like much extra work especially as they say....."While your in the neighborhood". Without proof that the water pump was replaced recently be ready for it to go soon. This could be another preventative maintenance to avoid trouble later....Lets say in the middle of summer when it is 5,000 degrees outside...

As for the Airmatic sounds like you already removed and replaced all four but here could be a tip to have the new one last a bit longer. I can't speak for MB but I had a Buick with the rear air suspension. I pulled the air suspension fuse in the fuse panel. Pulled it right when I arrived home to make sure it was level and removed fuse. I am not sure if MB might be smarter than that but it worked on the Rainer.

Man Jahquan3, your E550 has so many things go wrong, I would have kicked it to the next guy quite a while ago. You're making mechanic payments rather than car payments.

Sorry was going to update this post this week. As I finally got the replacement bag a week ago and had it put on this past Thursday. I've had it back several days now and it doesn't sit over night any longer. I think at this point I've replaced almost every components of the Air suspension.

That's part of my issue. I've put so much money into my car that I feel like I might as well keep it forever lol. If I was a little more handy and had a little more time on my hand to DIY it would be a slam dunk to keep it for awhile longer. Luckily I've been paying at a reduce cost vs going to the dealer. I'm actually going to get a couple of more things done in the next month or two. I believe my O2 sensor needs replacing and I have a leaky gasket that is dripping on a belt. It's causing a pretty distinct smell every so often. I can probably get both done for about $500ish. Haven't fully completed my research yet to confirm this.

Thanks for the feedback. I have some more work to get done shortly, so I'll make note of the Water Pump as I have not replaced that yet. I'm not aware of the suspension fuse trick. Not sure if the Mech tried that either.

what gasket is leaking? Oil cooler?

This I'm not 100% sure of. At 1st the dealer mentioned the Centrifuge Plug but said it's no rush. Then The European Indy mentioned a leaky gasket last year and the tech that's been working on my car recently alluded to the same. The most recent tech is really only my go to for the suspension/tire related items. I'm going to have to go back to the European Indy for further clarity. That'll be where I get the O2 sensor work done as well anyway. Advanced German Auto in Metchun NJ is great they will match any price you have on parts (In case anyone is in the area) . Only issue is they only have 2 bays so it's not easy to get in and out in a timely fashion. Now that I have an extra car for myself there's not as much rush as in the past. I'll report back with my findings at that time.

lol my dealer told me the same thing. The leake is from centrifuge but it could wait. They said 500 lol
...replaced it myself 2 weeks later for 15 bucks.
ughh them dealers are heartless sobs
good luck with your leaks man