W163 Heater Problem

ferrispedro

Senior Member
Joined
Sep 12, 2009
Messages
96
Reaction score
0
Location
Donaghadee, County Down
Your Mercedes
ML270 CDI
I have a problem with my ML270 heater. It seems to work well then when I go round a roundabout I lose my heat and have to build it up again. Feels to me like a big air lock somewhere in the system so how do I go about bleeding it. Diagrams and location of heater hoses would be appreciated.
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
367
Age
89
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
Could be a flap problem, not much to the water part

m.mycat
 

Steve@Avantgarde

Forum Supporter
Authorised Forum Supporter
Joined
Dec 8, 2009
Messages
7,314
Reaction score
1,955
Location
Bristol/Somerset
Website
www.avantgarde-automotive.co.uk
Your Mercedes
E300 Coupe AMG Line PP/NE, SLR McLaren Roadster, SL55 & C32AMG
I would check the coolant level to start with!!

There does seem to be a air lock issue, if it was a flap problem then you would hear the flap motors clicking away behind the dash.
 

panason1c

Senior Member
Joined
Apr 19, 2004
Messages
1,927
Reaction score
7
Age
70
Location
Somerset, UK
Your Mercedes
Mercedes ML270CDI, VW Polo 1.9tdi, BMW K1200RS
Normally, the ml cooling system bleeds itself without any 'outside help'. Might be an idea to check the auxiliary electric water pump is working.
 
Last edited:

panason1c

Senior Member
Joined
Apr 19, 2004
Messages
1,927
Reaction score
7
Age
70
Location
Somerset, UK
Your Mercedes
Mercedes ML270CDI, VW Polo 1.9tdi, BMW K1200RS
Thanks,where would I find that?

As you look at the engine, follow the coolant pipe from the left of the plastic coolant header tank, it connects to the aux electric pump (which is to the right of the battery).

This pump should run at the same time the engine is running and then continue running for a further 5 minutes (approx) after the 'hot' engine is turned off.
 

panason1c

Senior Member
Joined
Apr 19, 2004
Messages
1,927
Reaction score
7
Age
70
Location
Somerset, UK
Your Mercedes
Mercedes ML270CDI, VW Polo 1.9tdi, BMW K1200RS
How will I know if it is running,vibration or some other indicator? Thanks again. Peter.

You should be able to hear it if you put your ear to it, or, if you squeeze the (soft) hose that comes from the top of it you should feel resistance as you stem the flow from the pump.........its common for them to burn out the brushes, i took mine apart and fitted new brushes (got them from a local electrical shop and filed them to fit) a fiddly job but saves a lot of money on buying a new one.
 

panason1c

Senior Member
Joined
Apr 19, 2004
Messages
1,927
Reaction score
7
Age
70
Location
Somerset, UK
Your Mercedes
Mercedes ML270CDI, VW Polo 1.9tdi, BMW K1200RS
Aux pump is #104....
 

Attachments

  • pump.jpg
    pump.jpg
    19.8 KB · Views: 87
OP
F

ferrispedro

Senior Member
Joined
Sep 12, 2009
Messages
96
Reaction score
0
Location
Donaghadee, County Down
Your Mercedes
ML270 CDI
  • Thread Starter
  • Thread starter
  • #11
That is brilliant, thanks. I was reading somewhere that someone found a VW Passat pump that was similar and a fraction of the cost of a MB one. Are the brushes easily removed? Also your diagrams, are they from the Russian site?
 
OP
F

ferrispedro

Senior Member
Joined
Sep 12, 2009
Messages
96
Reaction score
0
Location
Donaghadee, County Down
Your Mercedes
ML270 CDI
  • Thread Starter
  • Thread starter
  • #12
You should be able to hear it if you put your ear to it, or, if you squeeze the (soft) hose that comes from the top of it you should feel resistance as you stem the flow from the pump.........its common for them to burn out the brushes, i took mine apart and fitted new brushes (got them from a local electrical shop and filed them to fit) a fiddly job but saves a lot of money on buying a new one.

Had a listen using the screwdriver stethoscope and heard nothing.Also tried pinching the top tube but no reaction so I am guessing the pump brushes have had it. A couple of years ago you recommended Solent Tools for the brushes,how did you know which ones to ask for. Peter.
 

panason1c

Senior Member
Joined
Apr 19, 2004
Messages
1,927
Reaction score
7
Age
70
Location
Somerset, UK
Your Mercedes
Mercedes ML270CDI, VW Polo 1.9tdi, BMW K1200RS
Had a listen using the screwdriver stethoscope and heard nothing.Also tried pinching the top tube but no reaction so I am guessing the pump brushes have had it. A couple of years ago you recommended Solent Tools for the brushes,how did you know which ones to ask for. Peter.

I cant remember the size of the brushes but you will need new brushes 'with tails' that you will need to solder to the motor contacts...... i removed the brushes from the motor and then gave the measurement details to solent over the phone and they sent new ones to me (on receipt, i cut the length to suit), the cost was about £10 i think.

Over the 9 yrs i've owned my ml i've renewed the brushes twice now, Previously, i'd bought similar brushes from a local electrical store and filed them to fit...........the choice is yours......
 
Last edited:
OP
F

ferrispedro

Senior Member
Joined
Sep 12, 2009
Messages
96
Reaction score
0
Location
Donaghadee, County Down
Your Mercedes
ML270 CDI
  • Thread Starter
  • Thread starter
  • #14
I cant remember the size of the brushes but you will need new brushes 'with tails' that you will need to solder to the motor contacts...... i removed the brushes from the motor and then gave the measurement details to solent over the phone and they sent new ones to me (on receipt, i cut the length to suit), the cost was about £10 i think.

Over the 9 yrs i've owned my ml i've renewed the brushes twice now, Previously, i'd bought similar brushes from a local electrical store and filed them to fit...........the choice is yours......

If I put a bit of copper pipe between the hoses could I use the car whilst I remove the pump to work on it?
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
367
Age
89
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
Yes and no problem at all :D:D
 


AMF Automotive - We are an independent Mercedes-Benz and AMG specialist located in Paddock Wood, Kent, with full Mercedes Diagnostic equipment. We offer a full portfolio of tuning options for AMGs and can cater for all your Mercedes needs.
Tel: 0203 384 4644www.amfmercedes.com/
Top Bottom