2023 E350. Around 38k miles. Noticed yesterday the low coolant warning came on. I figured since it has been -20’ here in NY it’s just acting wonky. I checked the coolant level and double checked the cap. All is good. Today it’s much warmer and it was gone until late in the day when it came back on. No coolant leaking anywhere or smells of any kind. No smoke. Car runs 100% normal. No codes. Any ideas?

 

May not be a problem. I would put in a few onces of mixed fluid and distilled after checking with dealer for correct procedure. Do not top it off, as it may expand in warmer weather. Then, i would forget about it for awhile, and maybe check level again in a few months.

 

The odd thing is with this situation is that the coolant level is good! No signs of leaks. The cap has been replaced. I let it go for a while but then the light came back on. I am at a loss.

 

So today I was low on coolant again. I filled it up. I ordered a OEM cap from FCP. Should be here Monday.

Car drives 100%. No white smoke. No CEL. No rough idle. No leaks under the car or visible under the hood.

 

I doubt an expansion tank cap would be your specific issue (unless you see white crusty dried residue around the expansion tank or around the cap its self). When the car warms up to temp, and you carefully open the cap for the expansion tank after 5-10 minutes after turning off the car, does it hiss/relief pressure from the tank? If so, your cap should be fine. If it doesn't, your cap or your tank might be faulty.

I would check with an OBDII scanner like an Autel to confirm all perimeters are okay (thermostat, coolant level, etc). I would also check your water pump and around the engine/radiators to see if there is a leak somewhere.

 

Thank You for the suggestion. I am going to try that.

 

The initial question to sort out:
True leak OR failed sensor ?

I believe it is: low coolant caused by a slow leak. Meaning coolant is getting low, Not a crazy sensor.

Confirm then we can search for coolant release.

 

Update: so I ended up placing not the cap, but the car itself. So come to find out after I filled it with coolant it went weeks with no issues. Unfortunately, the car‘s life came to an end when somebody hit it in the parking lot at Whole Foods. Insurance had up more than I anticipated So now the 2023 E350 is totaled. Nobody was inside so we are all good. Replacing it with a 2023 E450 sedan I found with just 5,000 miles over in CT. Picking it up next week.

 

that's a happy ending upgrade of sort.
Congrats on your new 450

 

Thank You. Very excited! I have this very odd feeling in my gut that my E350 issue could have lead to an engine failure as we have seen on some of the 4 pot cars. I just have this odd feeling it was a blessing in disguise? I could be wrong or paranoid. Anyways! E450 here I come

 

I wouldn't say it would've lead to an engine failure. If youre losing coolant the worst that could come to would probably be that you're head gasket is toast, requiring you to do replace it. But people have coolant leaks for years and are fine with it.

I am glad you're okay and no one was in the car when the accident happened. Cars can always be replaced, lives can't. So your new car is a blessing in disguise.

I was going to say check your suspension of the new car if you're buying used in CT (since the roads are sh*t) but i don't think anything serious could've happened to the suspension in the first 5,000 miles. Enjoy and be safe!

 

Fortunate turn of events! Engine in E 450 is much better than the 350. I also have a 23 E450. How much did you pay the guy to hit your car? People don't drive that fast at my whole foods.

 

It doesn't take much to total a car these days. A 15mph hit to the engine compartment will do it.

 

So the car was sitting in the parking lot. Lady in a Ford F250 truck with a plow on it came around the corner at about 15-20mph and smashed into the front of the car. I had the car backed in. Entire front was smashed up. When the insurance adjuster came he looked at me and goes I can already tell she is gone. I had a hard time myself even listing the parts that would be needed to replace and fix it. The back ends was hit as well as the car was pushed into a pole light. Took my check and picking up a E450 now.


I just wonder with that coolant leak since these 4 cylinder engines have those issues. It was CPO still anyways but oh well. I cannot wait for that I6.

 

That is exactly what it was. With all of the tech now a days. A simple $500 fix to the eye could turn into thousands! That is what happened with one of my work vans many years back.

 

You are correct it definitely could of been a head gasket.

It is a CPO car but I will definitely be looking the car over with a fine tooth comb. We all know CPO from anyone doesn’t always mean much now a days.

 

ROFL

 

Picked up the 2023 E450. Love this thing!

 

Enjoy your new and improved ride! Just don't park in that spot again!

 

Glad all are ok, and congrats on your new ride
R,
2Merks

 

Your going to love it, I just bought one with similar miles in Manhattan yesterday and drove it home to CLE, it's just an incredible car with lots of horsepower.Mercedes Manhattan is a companyowned store and mine was a leftover that turned into a corporate car for some executive that lived in Manhattan.

 

I just drove mine home from Manhattan to CLE, this E450 is over the top, very fast,rides great, the distronic plus changes lanes by itself if I use the turn signal

 

Nice! Yea the E450 is great! Really love it so far! Like my W212 I turned off all the self driving BS. Not a fan of that. I am glad I found a 2023 as I like buying the last year models.

 

I turned off the lane keep, blind spot, HUD. I love the massaging seats like in my 212 and other MB’s. These ones are best to use. More options of what you want.

 

Yes, I have all the options also, mine was an unsold '23 so my in-service date is Sept.'24! so factory warranty until '28 and a year of certified coverage after that! I did get a folding milk crate in the trunk I cant quite figure out and the run-flats are super stiff over bumps despite the 36 psi pressure, no spare so I hope they improve before I need new ones or I'll buy another wheel and tire for the trunk, apparently a jack and lug wrench also What do you think about the lighting package so far?