Oil Pressure Sender

Now here is a mod I am ALL IN on. Would love to retrofit an aftermarket gauge in a discrete spot that reads oil pressure in real time.
 
Jefco said:
When you first put the key in the 'run' position, you have zero oil pressure, and the light should come on. This is a test you can do every time you start the car.
Click to expand...
I was wondering if that was the case. I will see what mine does. If it doesn't light up perhaps i have an LED light backwards. That will be my first check anyways.
 
What oil pressure range does the X1/9 run with using the stock pump? What are the voltages the stock gauge limits to?
 
Ulix said:
3.5 to 5 bar according to the Fiat spec sheet.
Click to expand...
3.5 to 5 BAR ~ 50 to 73 PSI. That must be a maximum pressure at higher RPM's with thick oil. In reality an old engine with typical wear, hot oil, idle RPM could be as low as 15-20 PSI and still be "normal". But that "normal" certainly isn't ideal. Personally I'd like to see a minimum of around 40+ PSI at all times. And don't forget "pressure" and "flow" are two different things; pressure will increase if flow is restricted, and vice versa.
 
I have an engine as shown above without the oil pressure sender port. Today I received a dual sender unit from China (cheap, only 6 Euros) and my plan is to connect it to the "idiot port" to feed both the warning light and the oil pressure gauge. The Chinese sending unit has a 1/8" NPT connection and does not fit without an adapter. Does anyone know the size and thread type on the engine? -I need to know to buy the correct adapter to fit the new dual sender unit.
I am aware that the reading of the gauge will probably not be very accurate, but that is not very important. -I would be happy if the needle on the gauge at least shows something.
 
Bjorn Nilson said:
Does anyone know the size and thread type on the engine?
Click to expand...
I think it depends on the year and specific engine you have. I know the senders came in different thread sizes, but not sure which senders that applies to and for what years, etc.
I've adapted the sender hole thread size on a few of my engines. In some cases I retapped the hole, in others I got an adapter. Some threads are not common (including a lot of Fiat stuff), so finding proper sized adapters can be difficult.

I don't see why the gauge would not be accurate. Can't imagine it to be as bad as all of my stock gauges are.
 
Bjorn Nilson said:
I have an engine as shown above without the oil pressure sender port. Today I received a dual sender unit from China (cheap, only 6 Euros) and my plan is to connect it to the "idiot port" to feed both the warning light and the oil pressure gauge. The Chinese sending unit has a 1/8" NPT connection and does not fit without an adapter. Does anyone know the size and thread type on the engine? -I need to know to buy the correct adapter to fit the new dual sender unit.
I am aware that the reading of the gauge will probably not be very accurate, but that is not very important. -I would be happy if the needle on the gauge at least shows something.
Click to expand...
I was able to find a M14x1.5 to 1/8 NPT connector. From what I read, make sure to not get the brass connector as they cant handle the torque and vibrations and tend to shear off.

My VDO sensor i bought, currently somewhere in a UPS truck is VDO 360-009D with a 1/8 NPT thread. At least it should be 1/8NPT. From what i read and understand, it should also provide a signal for the stock idiot light.
 
Dr.Jeff said:
I don't see why the gauge would not be accurate. Can't imagine it to be as bad as all of my stock gauges are.
Click to expand...

Jeff, he is plannung to use the stock gauge with the VDO sensor.
This will make the gauge at least read backwards. Possibly it will peg the gauge in wither direction and just be a second idot light.
 
Here are the specs for the VDO sensors.
Text is in german, but easy to follow.
Each block is for a different sensor, differentiated by their max pressure rating. 2 bar, 3 bar, 5 bar...
Just pick the rating for the sensor you ordered.

Widerstandskennlinie 2 Bar Druckgeber:


0 bar - 10 Ohm
1 bar - 100 Ohm
2 bar - 184 Ohm


Widerstandskennlinie 3 Bar Druckgeber:

0 bar - 10 Ohm
1 bar - 69 Ohm
2 bar - 129 Ohm
3 bar - 184 Ohm


Widerstandskennlinie 5 Bar Druckgeber:

0 bar - 10 Ohm
1 bar - 48 Ohm
2 bar - 82 Ohm
3 bar - 116 Ohm
5 bar - 184 Ohm


Widerstandskennlinie 10 Bar Druckgeber:

0 bar - 10 Ohm
2 bar - 52 Ohm
6 bar - 124 Ohm
10 bar - 184 Ohm


Widerstandskennlinie 16 Bar Druckgeber:

0 bar - 10 Ohm
4 bar - 62 Ohm
8 bar - 108 Ohm
12 bar - 148 Ohm
16 bar - 184 Ohm


Widerstandskennlinie 25 Bar Druckgeber:

0 bar - 10 Ohm
5 bar - 53 Ohm
10 bar - 92 Ohm
15 bar - 125 Ohm
25 bar - 184 Ohm
 
Ulix said:
Jeff, he is plannung to use the stock gauge with the VDO sensor.
Click to expand...
I misunderstood. I thought we were talking about a VDO sender and gauge.

What's nice about using a VDO gauge with a VDO sender is all you need to do is match the bar spec. For example all of their 3 bar pressure senders work with all of their 3 bar gauges...regardless of what style, age, application, design, etc, etc.. VDO has been good about keeping the same basic parameters for how their products are designed. In my case I have several old VDO gauges from various vehicles that I will use, to keep a "period correct" look for the dash. It also makes it easy to reuse your gauges from one project to the next without having to buy all new gear again. Even if the engine has different sender fitting sizes you can just get another VDO sender that fits the hole and it will work on your VDO gauge.
 
Dr.Jeff said:
I misunderstood. I thought we were talking about a VDO sender and gauge.

What's nice about using a VDO gauge with a VDO sender is all you need to do is match the bar spec. For example all of their 3 bar pressure senders work with all of their 3 bar gauges...regardless of what style, age, application, design, etc, etc.. VDO has been good about keeping the same basic parameters for how their products are designed. In my case I have several old VDO gauges from various vehicles that I will use, to keep a "period correct" look for the dash. It also makes it easy to reuse your gauges from one project to the next without having to buy all new gear again. Even if the engine has different sender fitting sizes you can just get another VDO sender that fits the hole and it will work on your VDO gauge.
Click to expand...
I purchased the 5 bar sender and gauge for my vehicle. I plan to put the gauge next to the wide band gauge where the ash tray goes on the center console. I was never able to find a media player that fit there with decent reviews. I guess it will get hidden behind the Bertone dash Speaker.
 
Ulix said:
Jeff, he is plannung to use the stock gauge with the VDO sensor.
This will make the gauge at least read backwards. Possibly it will peg the gauge in wither direction and just be a second idot light.
Click to expand...
That's what I am aiming for. As per specification, the Chinese sender will show 0-10 bar. At 0 bar (unmounted) it has lots of resistance and at least in theory that will drop in steps down to 0 Ohm when fully pressurized (10 bar). So I don't think it will read backwards. The standard idiot sender measures 14mm in diameter but I am not sure about the threads. I will at least try with a M14/1.5 to 1/8NPT adapter to find out if it works.
 
Bjorn Nilson said:
I will at least try with a M14/1.5 to 1/8NPT adapter to find out if it works.
Click to expand...
I'm not positive but I seem to recall it is not a 1.5 thread pitch. Pretty much everything on these cars are a fine or very fine thread, so it might be 1.25. I measured it back when I was converting all of my senders to aftermarket but now I do not remember what it was, sorry. I know it took some searching to find a adapter to fit it (also converting to 1/8" NPT). Most were for the more common pitch (1.5).

Also, be aware that some senders are 1/8 "BSP" which is NOT "NPT". BSP (British standard) is the most common pipe thread worldwide (the USA is the only place that uses NPT) and is a straight wall rather than tapered like NPT. There is a tapered British (worldwide) standard pipe thread also, but it has a different thread pitch. Therefore either type of BSP will not seal in a NPT hole and vice versa. Unfortunately many sources will simply say "1/8" and not specify if BSP or NPT. Or even worse, some give the wrong type (e.g. say NPT when it is really BSP) - I presume just to sell more parts. I've purchased fittings from large USA companies that were sold as NPT but were actually BSP. So if things don't feel right as you begin to hand thread them together, stop and measure it. One simple way to tell if a male fitting is BSP or NPT is to hold two small straight edges along the opposite sides of it. If they are parallel then it is a non-tapered thread (BSP). If they are angled toward each other then it is tapered (NPT).
 
AKimball92 said:
Everywhere I have read said its M14x1.5
Click to expand...
That's good news because it is a more common thread. Like I said, I did not recall for sure. It might have been another fitting that I had difficulty adapting. I know a lot of threads on these engines are not standard or common.

Also keep in mind there are different sender/sensor sizes used on different years. I think it might be the temperature sender(?) that had different sizes though? I'd have to check my notes to see what it was that came in a couple sizes (diameters). But it is worth noting they may not all be the same so don't automatically assume things without checking what is on your particular engine. Hopefully someone has better details to add.
 
You must log in or register to reply here.
Back
Top