Topping up coolant

[A250 Bennyboy]

Hi all
My drive back from work today I got this telling me to top up the coolant level
Forgive me for sounding daft but do I just top it up with tap water or do I have to use deionized water?

Only just got it back after having the sensor and thermostat replaced on the coolant system, now I thinking maybe a hose has come loose or I have a leak? Not having much luck lately, hope I've not bought a duck egg!!
Cheers
Ben

 

[A250 Bennyboy]

I've just had a read through the online owners manual and it say to top up with coolant that has been approved by MB so looks like another trip to the dealers.
Cheers
Ben

 

[Broomel]

May have been an air pocket in the system after the thermostat change which has now cleared resulting in the low level.
Take it back to who changed the thermostat to resolve.

 

[A250 Bennyboy]

Thanks for the reply I'll pop into the dealers in half hour.
Cheers
Ben

 

[A250 Bennyboy]

Had my coolant topped up and again today on my drive to work its flashed up a warning about coolant level, must have a leak in the system? Only steam was raising from under my bonnet Grrrrr.
Not a happy chappie Alex the guy at MB is going to see my wrath.

The service I've had so far leaves a lot to be desired, last time they had my car for 3 days they couldn't even provide me with a loan car, looks like they have coursed a leak in the coolant system. When I phoned them on Saturday find out what coolant I needed to top my system up they told me go halfords as the service department finished at 1pm.
I asked if she was having a laugh, but she was quite serious, when I asked her if there was anybody around who could look up the info I was after she put me through to the brake down department lol

 

[MancMike]

If steam is escaping, then pressure is escaping, meaning the coolant can boil, meaning more steam, and so on.

It could just be the coolant cap not tightened properly. See if you can see where the steam is coming from.

 

[A250 Bennyboy]

When I parked up this morning I had the bonnet up see if could find where the steam was coming from but hard to tell really?
The cap was tight on but looks like it's seeped out or something as I have dried coolant residue on the reservoir tank tank, how corrosive is this fluid to things like mounts and pipes and paint work?
Cheers
Ben

 

[MancMike]

It's not corrosive at all. That'd be stupid. It's the opposite of corrosive. It has anti-corrosive additives. Otherwise it'd dissolve the rubber pipes from the inside out, along with gaskets, etc.

I think you're thinking of brake fluid, that's bad news for paint work.

 

[Flackadder]

Get the MB rescue type peeps to come and sort it, or recover it.......really is that easy.

 

[A250 Bennyboy]

Didn't think it was corrosive but had to ask, I may just phone the brake down assist and get them to sort it out, at least if they can't fix it by the road side I'll get a loan car as they bring one with them just incase.
Topped it up myself as I can't get in to see them now till tomorrow, if it throws up the warning on the drive to work in the morning? Then I'll call them out to my car and they can collect it, I'm going end up warping the head or worse if I'm not careful.
Thanks for the help and replys much appreciated

 

[A250 Bennyboy]

PS if anyone needs to know the grade of coolant you need for an A Class A250 it's 325.5 for the neat coolant mix at equal parts or the ready mix coolant is spec sheet 326.1 this is the one I bought as it makes it easier.
Took me an age to find this out.
Cheers
Ben

 

[A250 Bennyboy]

OK so since I've had this problem with the coolant system, I have topped it with approx 1300ml of coolant and had it back into MB only for them to also top it up. Approx 8ooml
It's definitely got a leak in the system but MB are in denial
So when it needs topping up again then they might realise I was right.
Not trying to tell them how to do their job but come on.
And when I say they topped it up I mean right passed the sensor and nearly brimmed it? Surly this can't be right ??
I can see me composing another complaint to MB Grrrrr
Cheers
Ben

 

[B-BOY]

I had a similar problem with my C250 petrol, when I first bought it engine light came on followed by top up coolant. Taken it to my dealer the response was sorry no leak but they topped it up for me (total and utter lie).

Same problem came up with in a week top up coolant, this time I had taken it to another dealer who found a leak in the radiator. They put it down to manufacturing fault and replaced it under warranty, no problems since the work had been carried out.

Have you tried a different dealer?

 

[A250 Bennyboy]

No I haven't tried another dealers, I'm using the same dealer I bought the car from, I recently had a problem with the sensor giving faulty signals (or that's what they told me)
So they replaced the sensor and the thermostat whilst they was at it as both could be faulty, all under warranty.
Can only imagine they have left a hose clip loose or something, they steam looks like it's coming from the back of the engine but hard to tell the exact place.
It's not thrown the warning up yet, but they did near enough brim it, only been using it for work 16 mile round trip, but got do a few miles over the weekend.
Fingers crossed they are right but not holding my breath
Cheers
Ben

 

[toffee-pie]

OK so since I've had this problem with the coolant system, I have topped it with approx 1300ml of coolant and had it back into MB only for them to also top it up. Approx 8ooml
It's definitely got a leak in the system but MB are in denial
So when it needs topping up again then they might realise I was right.
Not trying to tell them how to do their job but come on.
And when I say they topped it up I mean right passed the sensor and nearly brimmed it? Surly this can't be right ??
I can see me composing another complaint to MB Grrrrr
Cheers
Ben

seriously, go to a different mechanic.

That MB place seems clueless.

A coolant leak should be pretty obvious, if they are flaffing around with you its not good. I would just tell them take a hike and get it to someone who cares.

The fact you bought the car from them is irrelevant, I would not trust that place to do an oil change.

 

[streethawk]

Had it where I've had a pin ***** in rad which didn't show signs of leaking and the only way I noticed was on a cold morning I could see a small steam jet coming from rad.

 

[zipdip]

Well you say the steam seems to be coming from the back of the engine,this could be a core plug,I despair at MB main dealers,any back street mechanic can find a water leak,they just take the top off the top up tank screw on a device and then use a bike air pump to pressurize the system,then look for the stream or mist of water coming from where the leak is,maybe that is the best course to take,get a mobile mechanic to come round he will find the leak then if the rad or core plug take it to MB and tell them where it is and demand a car while they do the repair.

 

[A250 Bennyboy]

The other nearest MB dealers is Stockport I think? I've just had to top it once again so definitely got a leak in the system, I'll pop into the Stockport branch tomorrow after work.
Thanks for the advice much appreciated
Cheers
Ber