Coolant Temperature Sensor Misfit

[LindesayOne]

Hello Folks,
For my 1969 280SL, I have just taken delivery of a coolant temperature sensor from Authentic Classics. Unfortunately it does not fit into my block. It has threads measuring 14mm which is 1 mm wider than my existing sensor.
If anyone can weigh in on what’s happening here it would be much appreciated.
It is described as being suitable for 100,111,112, 113 chassis.

[mdsalemi]

John,

First, of course, you'll need to get a return authorized from Authentic Classics.

Then, I'd contact the Classic Center in California and speak with them and see what they say.

It is possible that somewhere along the timeline of production for all the engines in all those chassis, that MB made a change, and that change may not have been well documented. I have purchased several parts over the years that didn't fit, and the reason is that someone in the parts department in Germany made an assessment of fitting without actually seeing the parts or understanding how they may be different.

It's also possible that Authentic may simply have the incorrect part. Sometimes these things happen.

[clunker]

@LindesayOne - interesting issue, FWIW I did look around at what is being offered and noted that Niemoller lists the similar thread count and shallow angle collar to Authentic, but Vintage Euro lists one with a style closer to your original one - see images.

I also found 3 or 4 different part number, which may be C or F version and/or fitment versions depending on W113 model:
113.043 113.044
  A 00 254 296 05
  A 00 254 297 05 or A 00 254 258 05
113.042
  A 00 254 227 05

[BobH]

This does seem strange, there don't appear to be any posts on here where others have experienced this problem
There are a couple of suppliers, maybe more, that supply a threaded adaptor, SL Shop have two, one for F and one for C, can't imagine whey these would be different, perhaps enquire to see if either of these would be a solution for you, and fit your head.  Niemoller also supply one, doesn't specify whether its for C of F, or both, again worth asking

https://parts.theslshop.com/mercedes-benz-sl-w113-threaded-adapter-for-celsius-temperature-gauge/

https://parts.theslshop.com/copy-of-mercedes-benz-sl-w113-threaded-adapter-for-fahrenheit-temperature-gauge-/

https://www.niemoeller.de/en/w113/w113/B044/543/c01341-connection-fitting

Hopefully one of the more experienced on here has had the problem and found a solution

[Pawel66]

There are different part numbers for F and C scales.

But within the F range, there was change at chassis 113043 002980 (maybe that is when the sensor moved from elbow to block, not sure).

I am afraid it is not accurate to say "for W113 cars".

[LindesayOne]

Wow! I continue to be amazed at how selfless people step forward on the forum with useful advice. Thanks guys!
Use of the adapter would seem to be the simplest solution. While visiting the UK in a couple of weeks, I'm planning to drop by the SLShop, so that will be my first line of investigation.

John 

[rwmastel]

Maybe you can make time to stop by here:
https://www.colinferns.com/

[rwmastel]

If your parts supplier is not asking you for VIN and/or engine number, you should cross shop other vendors who do and compare your experiences in getting proper parts.  I have a 230SL parts book and an incredible number of parts changed during 230SL production run.