Remove / install temp sensor in thermostat E class220cdi

[ManofKent]

Hi all.
I am changing the thermostat on my 2003 E class 220 cdi. The old stat is off, but it has the coolant sensor in it.
I have removed the metal clip. It is stiff or stuck inside still.
How do you get it out?
The new stat I bought does not have a sensor included so I guess I just have to put the old one back in? Is this OK and if so are there any tips on getting it back without breaking it or leaks.

Many thanks.

John

 

[ManofKent]

Just an update. I soaked it in release oil, left it for about 10 minutes and it sort of popped out with a gentle push from inside the thermostat.
This is my first repair on the car. I am not used to Mercedes yet! But obviously bought a poor substitute for a stat. I had to tap two holes M6 for the brackets.
And I paid more than for a proper one with sensor. Gr. Never mind, lesson learned.
So I will order a new complete stat now, but the non standard repla cement is on so it will be interesting to see how it all goes.
I cant test it yet as the red radiator drain plug snapped inside the housing as I gather they do. It is out ( hot screwdriver tip from this forum- thanks) and a new one should arrive on Monday.
John

 

[OneForTheRoad]

Even mb stats come with no thread in those holes. When you put the bolts back in they cut a thread .

 

[jaymanek]

The mb part does come with a sensor in it.

 

[ManofKent]

Thanks. We shall see if the O ring on the sensor holds. If the sensor works but leaks I could just replace the O ring.

I didn't know the genuine stats aren't threaded. It was easy enough to do though.

John

 

[Salal]

MB sells the thermostat for that engine for about £40-50 and are manufactured by BEHR. It would have a been a good idea to lubricate the seal with silicone grease or Vaseline if you haven’t. But yeah keep an eye on it make sure it doesn’t leak. But If you do need a new seal, just get the right one from MB, there are quite cheap anyways.

The opening temp for that engine should be 92 degrees from what I remember, but some after market ones are different so keep that in mind for future reference, it’s usually stamped on the thermostat valve itself.

 

[ManofKent]

Thanks Salal. The silicone / vaseline tip is a good one and I wish I had thought of it in time! Fortunately the new thermostat was stamped 92 degrees. Phew.
The new drain valve arrived this morning. To insert it I put some vaseline on the O rings just to make sure they didn't split when going in.
I only did it up finger tight and all is good. No leaks from the drain or from the thermostat or sensor as far as I can tell.
I let it idle for about 30 mins and it just about got over the 80 degrees mark (it never went above 50 before) and then drove it through town and down the motorway for a round trip of 15 miles. The temp indicator sits a bit below the 100 marker so that is fine.
It did take longer than forever to warm up when idling - I have read that this is to be expected.
I would say the car was better to drive now, it was a little sluggish before and less so now.

Thanks for your advice and to those who are reading this.

Next job - change Auto transmission oil and filter.

John