My MB E500 4matic 2005 model showed low coolant take to workshop message for 2 weeks and I kept my eyes on temp but nothig quite happened until yesterday the dashboard went red and temp went shooting. I immediately pulled to curb and fortunately was able to leave it parked for cooling time. After sufficient cooling I opened to pour in say a bottle of water into high pressure resrvoir started the car and have been driving with no abnormal increase in temp. I have checked many times to see if water is leaking but I dont see any significant droppage in levels. I have also turned on thermostat to send in really hot air into cabin to see if any water leakage happens when it flows through the heating coils etc. I have to admit even now sometimes I see the cooolant low message coming on but no droppage in water level . I do have to take the car into MB dealer for B service. Should i ask them to check it out or will it un necessarily produce big bill.
If you’re worried about big service bills you shouldnt be driving a Benz.
The coolant level sensor in the reservoir is probably faulty.
Tester
I can’t make out what that means. You took it to a shop and they had it for two weeks?
That sounds like you have a slow leak and eventually did go low on coolant. When you first got the message, did you check the reservoir?
Slow leaks are like that.
You don’t need an MB dealer for anything. Find a local, independent shop with a good reputation and take it there for “B service” (whatever that means), and ask them to pressure test the cooling system.
You won’t pay 33 bucks for the sensor at your shop, probably twice that for the one in @Tester’s link. While $66 isn’t much, you will pay for a diagnosis to make sure what the problem is then pay for parts and finally for removal of the bad parts and installation of the replacements. If you’re lucky it might be 3 hours of labor. I don’t know what labor is where you live but at $200/hr you could spend almost $700. All this is a guess, it you asked about cost and this is a great big WAG at it.
I think some are missing this part:
Service B is the more involved service every 20,000mi or 2yrs, Brake fluid and cabin filter changed along with a list of inspections. We have several great options around here for German/European vehicles. One’s been in operation for 53yrs now. Much closer to us than the dealer 35mi away.
Mercedes and large bills ? That should not be a surprise . You have several posts where you don’t seem to like the repair cost of this vehicle . Might be time to buy a new more main stream vehicle that that does not cause you expensive problems .
Also if you do wait and let this thing overheat your repair cost will really be high.
Do I understand that your car was telling you that the coolant was low for two weeks and you didn’t check the level and add as needed?
If you don’ want big repair bills, don’t drive around with a low coolant light until the engine overheats. That is a good way to ruin an engine. You then put water in instead of coolant, now your colant has to be checked for strength. You don’t need a dealer, but you do need a competent shop because you c;early don’t have a clue.
If you don’t want big repair bills, don’t drive a MB, BMW or a lot of other Euro vehicles being a poser… But ignoring a low coolant light on a vehicle doesn’t help either… lol
In SF there is no independent Mercedes mechanic who does not charge pretty much the same as the dealer. All of them come up with 300/hr charge. I have tried and finally stuck to dealer. Atleast the guy makes sure of original parts, discounts, recall warranties
I see absolutely no reason to go to a shop that specializes in Mercedes-Benz
There’s probably an obvious problem, such as a coolant leak
Any shop with a pressure tester and the correct adapter should be able to quickly figure it out
I’m not comfortable with what you call the “high pressure reservoir”. Are you talking about the radiator cap on top of the radiator or the plastic remote reservoir.
In older vehicles, the plastic remote reservoir was an overflow tank and was not pressurized. A lot of newer vehicles use a pressurized remote reservoir, again plastic, but the radiator either does not have a cap or the cap that is on it is not a pressurized cap, instead the pressure cap is on the remote reservoir.
Do you now for sure which system you have?
It may be possible that you are due for a cooling system service. Check the maintenance schedule in your owners manual to see how often it needs to be done. Your dealer may have a record of when it was last done.
If it is due, or near due, simply have the service done at the dealer. Considering the age of your vehicle, I’d also recommend that you have a new pressure cap installed because that could easily be the source of your issues.
BTW, ignoring this issue will not make it go away. The longer you wait to address it, the more it is going to cost you. A LOT more.
Your best bet is to schedule your car into your preferred repair shop immediately for a diagnoses. There are several possible explanations for the symptoms and you need the shop to determine which ones they are for this case. Yes, it is going to be quite expensive, but almost certainly less than the repair bill you’ll get if the engine ever severely overheats. There are two obvious ways to reduce the repair bills, tool up and learn how to do the proper diagnosis repair yourself; trade this car in for a new car, then the problems will be covered under the new-car warranty.
This is what OP has
@db4690 … just curious, what’s the purpose of that little stub sticking out just to the left of the lid opening? For cooling system bleeding? One-way valve allows air in, but not out?
That’s where the hose hooks up
Ok, I was thinking the hose connected to the lower stub. I’m presuming the one lower down is an electrical connector then?
On both of my older vehicles that bottle isn’t intended to hold the full cooling system pressure, just a place for any overflow from the radiator to go. Newer vehicles seem to often use pressurized bottle. I’ve never understood what would motivate the change to a full-cooling-system pressure overflow bottle (reservoir) ?
hmmmm … thinking the advantage may be it simplifies the design of the radiator (or pressure control) cap?
