Technical Pressure and Temperature Sensor thread sizes

[Bleeding Knuckles]

Greetings,

Before I go and splash out my hard earned, can anyone tell me the specific thread size and pitch of the 126 engine crankcase Oil Pressure Transmitter Fitting???

Also, I need to know the specific thread size and pitch of the Oil Temperature Sensor location on the 'Abarth' branded 4L alloy sump???

I have the correct 'Jaeger' instruments, but some dimwit has fitted the wrong sensors and they are rather expensive (the probable reason for not fitting them) otherwise I'll have to drain the oil!!!
Thanks in advance.

Ian.

 

[RogerNZ]

Hi Ian, in my experience the 4l Abarth sump does not come pre-drilled for a temp sender, you have to do it yourself to match your sender so the thread you have now is anyone's guess. If you can post a pic of the sender you have in there now we might be able to figure it out.

I have a pressure sender somewhere so will check the thread and get back to you.

By the way, are you sure you have the wrong sender units? I thought the same re temp sender with my Jeager temp guage but it turned out to just be a bad earth.

Have you checked head or sump temp with a laser thermometer to confirm guage is not reading true?

Cheers
Roger

 

[stevehg]

When I was looking for pressure sensors the other day, axel has the standard pressure switch listed as M12 1.5.

cheers, Steve

 

[Bleeding Knuckles]

Steve, Rodger,

Thanks for the replies, sorry for the delay in getting back. The story so far - I pulled out the crankcase pressure switch and have found that it is M12 x 1.5 pitch the next problem was finding the correct sensor for my fitted gauge. Talked with Axel G and found that there were possibly two that would do, but, my gauge has an integral low pressure light too!! Only one cable to the sender made me think 'that's not right' so sat and thought about it. Noticed a spare connector running from the loom and just though to myself 'I wonder what that one does' (mild panic after considering I may blow a fuse or two) so, gritting my teeth for the flash and bang put the spare wire to earth!!!!! Lo and behold, the gauge needle swept over to full deflection - relief or what???? BUT, the only available two pole sensor is M14 x 1.5 pitch - bugger!!! It also seems that the only available sensor for the sump pan is M16 x 1.5 pitch??? You've got to love the European way with these - like walking up a hill thinking you've got to the top only to find a crest. I will drain the oil and check at a later stage once I have sourced an adaptor - oh and the new sensor needs to be out of the way of the thermostat flap too - Joy!!
Regards
Ian.

 

[stevehg]

If you don't have enough room, you can use a set up like to remote mount your sender...
http://pages.ebay.com/link/?nav=item.view&alt=web&id=281306980154

If you get the right hose adapters it will solve your M14 to M12 issue too.

 

[Bleeding Knuckles]

Thanks Steve - appreciated. I'll look into the room available and my wiring loom, it may make sense and I could mount the sender unit well away from the Thermo flap. Glad that the example shown has a braided hose as my stainless exhaust gives off a lot of heat! I'll post my solution.

Ian.

 

[Bleeding Knuckles]

OK, now that I have identified the make (vdo) and size of the pressure sensor how do I get the best pressure range? What is the best low pressure setting for the warning light?? If the gauge itself reads 0 to 80 bar do I need a high pressure sensor too?? Axel G recommend 0 to 5 bar !! Is this correct as the gauge will barely read?? Thanks in advance.

Ian.

 

[IanEmery]

Ian, are you sure about the preasure range of your gauge, 0-80 BAR!, as in 1160 PSI? I suspect you have a range wrong, that the gauge reads 0-80 PSI and that 0-5 BAR is correct.

Ian

 

[the hobbler]

Ian;
According to the book of words, the 'low oil-pressure' warning light is designed to come on when the oil-pressure drops to between 8.5 and 14psi (1 to 0.6 bar). All I can find anywhere, is that on the 126 (and I cannot see the 500 being very different) the normal running oil-pressure is between 35-43psi (2.4-3.0 bar). I would therefore suggest that if your sensor/gauge is set up to register between 0.5 and 5.0 bar (7.5-74psi) you won't be far out.

 

[Bleeding Knuckles]

Gents, if you look at item number 23334 in the Axel Gerstl site you will note that it states 0-80 kg/cm2 . I note hobblers and Ian's comments and wonder if the scale should read 0-8 kg/cm2 ????????

 

[the hobbler]

Hi Ian;
I think that Axel Gerstle must have his nuts in a knot!! By my calculations, 80KG/cm2 converts to 1139psi--and if your engine ever produces that sort of oil pressure!! However, look onto the 'Leo Van de Laan' website, in the 'dashboard' section he has a 52mm 'Abarth' oil-pressure gauge that reads to just 8KG/cm2, which converts to about 113psi The part number is DS7350 and costs E72 (about £53 at todays exchange rate). Right now is a good time to buy bits from abroad as the Euro is very weak.

 

[stevehg]

I noticed this last week when looking for senders for my guage. Axel are not wrong, as the guage is labelled up to 80 kg/cm2. If you zoom in you can see here...

Not being used to kg/cm2, I did the same and looked it up in BAR & PSI and came to the conclusion that it must be labelled wrong.

cheers, Steve

 

[AndrewHarvey]

My Veglia Borletti oil pressure gauge reads 0-80 & 0-110 its a dual scale.
There is no unit of measure shown on the face- any idea the correlation that means 80 & 110 are the same?

 

[Bleeding Knuckles]

Gents, appreciate the comments. The car came with the gauge fitted so the supplier is unknown Axel G happen to have the same instrument, but I agree that the gauge is either used on a different application, or simply labled wrong. Oh and Steve I have gone for the remote pressure sensor t piece as I could'nt find a short one that would clear the thermostat flap, just need yet another adaptor to sort the m14 x 1.5 to m12 x 1.5 fittings deep joy..Thanks all.

Ian.

 

[RogerNZ]

Hi guys. I can confirm that the Fiat 126 manual states that the lubrication pressure at 100 degrees C (212 degrees F) should be 35.5 - 43 Psi, or 2.5 - 3 kg/sq.cm. That's 2.44 - 2.96 Bar according to an online calculator I just Googled up.


I am in the process of fitting an oil pressure gauge to my car. I have already fitted the sender:


http://webshop.fiat500126.com/katalog/artikelinfo/2116/oil-pressure-sensor-2-piece


Now I just need to fit the gauge into the dash. I bought an 'Abarth' gauge from Axel's but it doesn't appear on their website anymore that I can see. I have included a pic below. You'll see it measures in Bar from 0-8, so should be ample for the expected pressure range. I note that the Jaeger and VDO gauges listed by Axel's read in kg/sq.cm with a scale from 0-80. Since 1 Bar equals pretty much equals 1 kg/sq.cm that scale seems way too big!?

 

[Bambino]

I have noticed this with old european Alfa gauges as well. The pressure gauges are calibrated in kg/sq.cm but read 0 to 80. I have it on good authority that there is supposed to be a decimal point in there so that it reads 0 to 8.0. Some of the very old ones had a lowercase zero following the numerals instead of a decimal between them.

I've attached a photo of the instruments out of my 1957 Alfa - same deal.

Chris

 

[RogerNZ]

Wow those gauges look good Chris. Pure art.

 

[Bambino]

Wow those gauges look good Chris. Pure art.

Thanks - many hours of patient restoration. Hopefully one day I'll have a car to wrap around them ...

Chris

 

[Bleeding Knuckles]

Greetings All,

Well, drained the oil after a quick buzz around the neighbourhood and removed a short temperature sensor from VDO. Lo and Behold it was a M16 x 1.5 fitting - result! changed the sensor as the resistance when hot was way off and fluctuating . Did find that the engine contained 3.8 Lt of oil with the contents up at the top level mark, but, have found that I was getting oil weeping from the dipstick, so I have reduced the level to half way (3.5 Lt) Now waiting for another adaptor for the remote oil pressure sensor with two functions - one for the low pressure light and one for the pressure indication, this system has been tested so should work when assembled. I'll just have to ignore the 80 Bar indication and think 8 Bar instead!!

Ian.

 

[Bleeding Knuckles]

The adaptor duly arrived and it has all fitted together correctly. One thing I have noticed is that the gauge indication when observed at switch on is maximum, but when the engine is started the warning light goes off quickly and the needle sweeps back to read a steady 3 Bar?? Is this normal with VDO sensors and Jaeger gauges??? The braided piping needed bleeding and I have not found the need to repeat this again. The wiring is much shorter and the whole system is mounted away from the flap valve and exhaust - another job done!!!

Ian.