Coolant Temp Sensor Replacement With Aftermarket One?

[Gilbertj66]

Good Afternoon Fellow Friends.

I have a topic that I believe could be very helpful if we can get a thread going. Maybe this has already been discussed and if so. Please replay back with the link so i can educate my self.

Is it possible to install a separate aftermarket temp gauge and engine temperature sensor? I've looked into this process of replacing the original one and if I'm not mistaken I would have to remove my steering column along with the dash.

I'm worried that I may break more trim and interior parts due to its age than i will be repairing  .

If someone has already done this could you please provide me with the kit you used. If not, could someone give me what the thread pitch or fitting size is on the coolant temp probe that goes inserted on the engine side. With that info i should be able to find something that works.

Attached are photos of my current sensor location and thread

Thank you in advance

[GM]

Are you sure this is not working?
Are you sure that the gas has not leaked out of the capillary tube connected to the temp gauge in the dash?

[Gilbertj66]

I have done the test to warm the the tip of the sensor and no change on the the gauge in the vehicle. At this point i could safely say from the tip of the sensor to the gauge something is not working. However I'm trying to avoid removing the dash as I'm afraid i will break pieces.

Would you by chance know the type of fitting used on the sensor side? Please see attached photo.

Going aftermarket on this is my goal. Even if it is temporary. Vehicle runs but i cannot drive without knowing what the engine temp is.

Best regards,
Gil

[GM]

Sounds like you've lost the gas in the capillary tube - the gauge works by thermal expansion of the gas in the tube, not electrical.
Check the tech manual for the process to remove the gauge.
It's not difficult, you just have to be slow and careful about doing it, being gentle to not kink the tube during removal and installation.
Then you can send the sensor/tube/gauge out for repair (Hartmut at Palo Alto Speedometer); he can guide you on the process and is very helpful.

If you don't want to DIY, sorry I can't help.

[Gilbertj66]

I understand how the system works. I need a different solution than to replace the factory system. I'm doing this myself. I just need to know the tread and fitting size in my photo. so i can run a completely separate gauge.

 if you cannot give me that information than you cannot help me.

Thank you

[rwmastel]

Gilbert,

Welcome to the Group!  Allow me to help you out with regards to getting things done on this site.

- Everyone here is an enthusiast and contributes voluntarily out of the kindness of their heart.
- The forums are broken down into many different sub-forums, or boards, so people's specific questions and needs can be more easily identified and resolved.
- Most people here try to keep their cars original as designed by M-B.
- When you wrote "At this point i could safely say from the tip of the sensor to the gauge something is not working." it could be interpreted that you didn't understand the factory system as the expanding gas in the tube is the only thing between the sensor and gauge.  GM was just trying to give you some help with that.
- Not everybody wants to keep their car original per MB design.
- This is why we have the "Research & Development" board, described as "Discuss Research and Development, including modifications that are not original or correct for the W113 series cars."
- Since you didn't post in R&D board, people probably assume you want it fixed per M-B design, even though you did ask "Is it possible to install a separate aftermarket temp gauge and engine temperature sensor?"

So, please don't get upset with the wonderful members here when you are brand new and are just getting used to how we operate.

I asked the moderator to move this thread over to R&D.

Did you use the search function?  Our forum has been on-line for 20 years, so perhaps someone else has asked about this, or already resolved it.

[dirkbalter]

I just need to know the tread and fitting size in my photo. so i can run a completely separate gauge.

Have you tried measuring the thread? Its likely a metric fine thread. I have an extra one and can get some dim tonight if you like.

[Gilbertj66]

I 'am unclear on why you feel like I'm upset with anyone rwmastel. That is not the case. I simply replied to his question.

I'm not sure how i could not be any more direct in my original question.

I understand he is providing help. However it is not the help i requested.

After I answered GM the first time I figured it was clear on what my intentions are. 

Nonetheless i welcome any feedback on how to properly use the site, since it is your understanding that i may not know how to do so.

Best regards,
Gil

[Gilbertj66]

That would be very helpful! I'm used to using AN sizing. I did measure it with my AN sizing wrench. It is close to 4AN. But i know its an NPT. Maybe a 1/8 NPT ? It would be great if someone could just confirm.

[BobH]

Hello, thread size is shown on here

https://w113.eu/geschlossen/Reparaturen/Wasserthermometer%20reparieren%20Mercedes%20Pagode%20W113.htm

[dirkbalter]

There you go. M14 x 1.5

[rwmastel]

if you cannot give me that information than you cannot help me.

I 'am unclear on why you feel like I'm upset with anyone rwmastel. That is not the case. I simply replied to his question.

I thought the above comment might have been you getting a little frustrated with not getting your question answered, and I just wanted to interject and make sure everyone remained civil.  We've got a very polite, courteous, helpful, friendly forum here, so I just wanted to make sure nothing escalated.  Sometimes what gets written in plain text loses it's subtle meaning, or people take the meaning differently.  I'm glad you got your thread info and good luck with your new solution.

[Gilbertj66]

BobH Thank you for that document. I was able to use google translate and it was very helpful. I will be spending some time now researching different kits to see if we can make something work.

Best regards,
Gil

[Gilbertj66]

Got it thank you for offering to help.

[Gilbertj66]

That is the lovely part about forums. Perception is in the eye of the spectator. Me personally unless its addressed to me i do not interject in others affairs unless i can provide value to the topic at hand. 

If someone violates community guidelines or is disrespectful in anyway then i would interject, and even then i feel it is the job of the moderator to interject. Nonetheless i thank you for your concern towards others and making sure no threads get out of hand.

Best Regards,
Gil

[lpeterssen]

Dear Gilbert

These link corresponds to a Mercedes Truck Temp gauge driven by an standard electrical signal coming from any vdo probe coming from later Mercedes

https://www.ebay.com/itm/394504631909?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=piB4-15ZT_O&sssrc=2349624&ssuid=xQJlZWrBRO-&var=&widget_ver=artemis&media=COPY

As you can see has the same form factor as original” w113 temp gauge”.  Just some trimming and will fit in the instrument cluster.

To convert it to work on 12v just replace the inline resistance that is on the back of it for one in exactly 50% of its original capacity.

As this temp gauge cost around 90$, and new repro gas driven temp gauges for pagoda can be found for 250$, I think that you may stay with the original.

Here the link for an original repro one

https://www.ebay.com/itm/254721276011?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=jC3_YjflRwC&sssrc=2349624&ssuid=xQJlZWrBRO-&var=&widget_ver=artemis&media=COPY

The option with the truck 24v temp gauge, makes sense when you live in countries like mine where everything is too expensive, and you may find NOS gauges for almost nothing.

Best regards
Eng. Leonardo Peterssen

[getsmart]

I love Leonardos' solution (and I think what Gilbert was asking for), I had thought about doing something like this to mine when I accidentally put a "hole" in my capillary tube and when I say "hole" I mean I accidentally cut it!!!!  :'(

A local guy here repairs them for $200 aud which is about ~$130 usd so in the end I did that, afterall one of my mantras for my restoration is to keep costs down. But I do like this elegant solution 

[franjo_66]

I love Leonardos' solution (and I think what Gilbert was asking for), I had thought about doing something like this to mine when I accidentally put a "hole" in my capillary tube and when I say "hole" I mean I accidentally cut it!!!!  :'(

Would you be able to share details of who in Melbourne repaired yours?
I am in Sydney but would be easy enough to post it down south
Thanks

[getsmart]

howardinstruments.com.au

[Gilbertj66]

Hello All!!

Just wanted to update this a bit. The Kit that i used can be found on Amazon. Part number Dorman 7-123. I used this to put a temporary temp gauge while I worked on the car doing brakes and other things. This kit does not require much modification that would prevent you from using the stock system in the future again. You just have to drill the most inner orifice ( not the threaded orifice) out to make the new tube fit.

Any questions feel free to ask. I simply mounted the gauge inside and works like a charm. Its in F' also!

[franjo_66]

howardinstruments.com.au

Thanks for that !

[Gilbertj66]

My pleasure! now on to the steering system!