water sloshing behind dash and losing coolant on c220cdi

[Charlie79]

Hi,

I have a 2006 c220 cdi estate which had a strange problem since I bought it. When I start the car, I hear sloshing noises behind the dash for a short while, it seems to disappear when the engine is warm. I am having to top the coolant up 2-3 times a week with at least 3-4 pints at a time.

I took it to my mechanic and he told me it was the expansion tank, and he replaced it along with hoses and fittings for good measure. The problem didn't go away.

The other day I took my car to have a front tyres changed; I saw a leak that seams to be coming around the expansion tank, and the mechanic at the tyre place told me it could be my water pump.

I read different posts that suggest, water pump, heater matrix, I cant be sure. I am very confused. has anybody had a similar experience? any advice is appreciated.

Cheers

 

[martyz]

If it was the heater matrix there will be water in the car,if it's external could be the water pump,radiator,thermostat housing,or any associated hoses,it should be easy to find,or it could be over heating and boiling back to the expansion tank.

 

[Charlie79]

If it was the heater matrix there will be water in the car,if it's external could be the water pump,radiator,thermostat housing,or any associated hoses,it should be easy to find,or it could be over heating and boiling back to the expansion tank.

No water in the car. The car warms up quite quickly the temp gauge is consistent on 80c. I will check the hoses and rad, where is the thermostat housing?

 

[rorf]

Find yourself a competent mechainic

 

[Charlie79]

Find yourself a competent mechainic

Thanks for the helpful reply. I want to know more before I find another so I don't get my pants pulled down...

 

[Dieselman]

The sloshing sounds like air gurgling through the heater matrix, due to the level being low.

If you can see water somewhere, have a feel around, it shouldn't be hard to spot the source of the leak.

 

[rorf]

Well I would do something pronto as your problems can only get worse and soon you will be sitting with a cooked engine

As Dieselman suggested, have a good look around in the engine compartment with the engine running to see where the water is coming from. Be very careful of rotating parts and using a bright strong torch can only assist in identifying the problem area.

Find yourself an independent Mercedes or German car specialist workshop to do the repair work.

No such thing as a cheap Mercedes

 

[LexCorp]

Are you sure the sound when you start the engine is not the fuel pump priming in the fuel tank under the rear seats? Mine does the same.

 

[Charlie79]

Well I would do something pronto as your problems can only get worse and soon you will be sitting with a cooked engine As Dieselman suggested, have a good look around in the engine compartment with the engine running to see where the water is coming from. Be very careful of rotating parts and using a bright strong torch can only assist in identifying the problem area. Find yourself an independent Mercedes or German car specialist workshop to do the repair work. No such thing as a cheap Mercedes

Thanks for the reply. I finally found out why I was loosing coolant. It was (drumroll) £7 rad cap. Old one had an old seal and wasn't sealing well enough, water was boiling in the expansion tank and leaking out. Replaced it two days ago, and problem is over. Pressurised system is keeping the coolant from boiling. Well chuffed.

 

[Charlie79]

Really found the cause

It was confirmed that it was a very small leak from the headgasket, replacing would cost £900. Sold at the auctions. Thanks for the replies.

 

[E240estate]

Exactly the same scenario I had with my Vito. Bought tad cap, well chuffed, pressurised the system and the existing small hg leak became a very big one a short while later. Replaced hg myself for a couple hundred, but I appreciate that option is not for everyone. Still in the process of getting it running right again.

 

[E240estate]

Rad cap, of course!