Coolant drain plug (engine)

[normanr]

Hi all
I can't believe I am having so many problems trying to find a drain plug I have messed about with loads of different cars in the past but this is a pain.

W202 Petrol 1999 engine drain plug for the coolant in the Haynes manual it shows it between two core plugs and it is a Hex bolt with a place to put a drain hose I don't have anything like that on mine all I have is a bolt with some sort of sensor on which I took off and had a hell of a job to get back on.

Does anybody know where the plug is and any chance of a piccy, I have had a torch and inspection light on the block but I can't see a drain plug.

 

[grober]

Its on the side of the block under the exhaust manifold and can only be seen from underneath and only from certain angles as its obscured by the steering box-almost impossible to get at.

 

[Dieselman]

ITEM 44. It should be just under the exhaust manifold.

 

[jaymanek]

I would just take hoses off and flush through rather than messing about with all that...

 

[normanr]

Thanks Graeme and DM
I have been looking on the wrong side of the engine as you say Graeme almost impossible to get at.
Nice diagram DM thanks once again for a lightening fast reply.

 

[normanr]

I would just take hoses off and flush through rather than messing about with all that...

I think that is probably the best thing Jay fancy putting a drain plug there?

 

[kth286]

normanr

What you probably took off was the knock sensor which has a special screened cable.

It is a key item to prevent damaging engine knock.

I trust you put is back properly.

 

[normanr]

Yes was very careful on that score,managed to get my arm right up inside to secure it but not to tight.
Thanks for the information

 

[normanr]

Just to carry on the saga Haynes manual says remove the thermostat and replace the housing to flush the engine which as we all know is what you do when you flush an engine,Haynes shows the diagrams but after the diagrams if you read on it says on petrol engines don't remove the thermostat from the housing as it will get damaged.

Haynes manuals are s---e why did they not put the warning at the beginning and where they show the diagrams I don't expect I am the first one to do it, I now have to buy a complete thing which is housing with thermostat costing £20.00+postage.

Just thought I would put this on to warn others.

 

[Dieselman]

In what way is it damaged.?

 

[normanr]

There is two cutaways in the housing that the thermostat sits in but you can't compress it to bet it back,it came out easy enough but there is a spindle goes up through the middle which won't line up allowing you to compress it to put back into the housing.
I will put a couple of pictures on in a minute so you can see.

 

[normanr]

Here we go DM
The places marked in red should mate back together but the spring is too strong to compress and also the spindle catches on the main body so it just won't compress.

 

[normanr]

Continued

 

[normanr]

I boiled it which took a bit of tension off the spring so I was able to get it back into the casting (not easy though).
It is opening and closing so hopefully it will be OK.

 

[Dieselman]

I've only just seen the pics and now understand. You needed to compress it to get it back into the bayonet fitting.

Why did you remove it from the casing.? Don't say..because you could...

 

[normanr]

Because the wording in the Haynes manual was remove the thermostat and replace the housing to flush the engine.

It will not flush with the thermostat cold because it will be closed do you not agree

 

[Dieselman]

Because the wording in the Haynes manual was remove the thermostat and replace the housing to flush the engine.

It will not flush with the thermostat cold because it will be closed do you not agree

Agreed, but as the system wasn't particularly silted up you could have just flushed from the top down.

Anyway, it's done now and a nice result.

 

[normanr]

You didn't say how pretty the wife was. (eat your heart out LOL)

 

[Dieselman]

Didn't want you to think I was fishing...

 

[grober]

The last time I bought a replacement thermostat for that engine from MB it came fitted in a new housing as one integrated unit.