AKimball92

True Classic
Does anyone know the resistance and limits to the OE oil pressure gauge? I am looking to add one to my 78' on top of the existing low pressure light. With that I would like to get a VDO or Kus sender with the M14x1.5 threads. These have both the sender and light attachments to eliminate the doubler/splitter to use both.

Link to the Kus example: https://www.svb24.com/en/kus-oil-pressure-sensor.html
Model no. 21570

Link to the VDO example: http://www.partdeal.com/vdo-80-psi-...contact-point-and-m14x1-5-thread-360-028.html

https://www.vdo-gauges.com/sensors/...si-warning-contact-7-1-psi-m14x1-5-30-28.html

Also one can use a SS flex line with a M14x1.5 adaptor and use any common dual sensor and isolate it from the vibrations and heat. Honestly even with the brake line and adaptor its still cheaper than a OE sensor + sender + splitter.

My block and engine below. Just to confirm, that's the oil pressure sensor above the separator correct? Will this location provide a good signal for a gauge?
IMG_3801.JPG
IMG_0011.JPG
 
Last edited:
Andrew, I spent quite some time researching this.
The stock gauge will not work with any other senders. It reacts inversely to resistance than the aftermarket gauges.
I.e. If your pressure rises, dour gauge will go down.
Pretty much only the stock sender will work with the stock gauge. And they will read way low.
If you want an accurate reading, you might want to consider an aftermarket gauger/sender combo.

Or just stick with the idiot light.
 
I'm with Ulix. If you change to the aftermarket sender (which I highly recommend), then you should also change the gauge for a matching unit. The stock gauges are not at all accurate nor reliable in my experience (and it sounds like I'm not alone on this). So using a VDO (or similar) gauge with matching sender will give you information you can actually use and rely on. The two-way senders like you noted are great; much better in my opinion than having a split fitting and two senders. I've converted to that type on all of my engines (with matching gauges). Maybe you can come up with a nice way to replace the stock gauge with a aftermarket one, in the original location on the dash. Or add the gauge elsewhere. Depending if you are adding other gauges as well (e.g. temp, O2, etc), then making a nice display panel with them together looks great.
 
When I switched to a 1500 without the oil pressure sender tap, I got one of those port doublers and used it with my 1300 sender at the idiot light port. Seems to act pretty much the same as it did with the 1300. I cannot vouch for the accuracy of the gauge but it does provide slightly more feedback than the idiot light alone.
 
I have no problem with the doublers and have had them on all my 1500 Xs. I use a mechanical gauge.
 
My dash only has the idiot light so I needed to fab up a way to show both this new gauge and the wide band sensor. I am still working out where to put it as these done fit nicely in the center console on the earlier dash. Either I cut up the speaker panel, which mine is cracked in the corner anyways with a spare in the cabinet, add a center section on the ledge, or somewhere near the center arm rest area. I really don't want to cut my dash. I had planned to use the speaker panel to hide a radio in it to eliminate theft. But that is so far away from the driver.

I also do not want to buy the AEM pressure gauge as that is $150+ unless everyone convinces me otherwise.

I will do some searching and probably get the VDO sender.

Has anyone had any issues with vibration or are we making up problems where their aren't any?
 
Not sure what you refer to as vibration problems, my spiders always had the nylon line and the Xs copper lines for the mechanical gauge with no issues whatsoever. Look for some gauge pods, not the ones that go on the A pillars but similar pods you can attach to the top of the dash with maybe sticky sided Velcro or double sided tape.
 
remove the voltmeter and fit the OE gauge, but that would mean an oe sender... you can get pretty cheap (lada so made in russia) units if you look.

Yep the OE Veglia transducers are not cheap, but they do last... and the OE ones do read pretty well... Older style OE transducers were actually adjustable, if you peer up the pressure hole, there's a small grub screw you can wind in and out to adjust, you would set / check them with a mechanical master gauge.

If you want accuracy, then you cant beat mechanical gauges, for both oil and water... I wouldn't build a race / competition car with anything but mechanical gauges for accuracy... cost of the gauges compared to cost of engines is tiny.

you MAY run into clearance issue to the breather cyclone with something as large as the dual VDO unit

BTW engine looks neat!

SteveC
 
Andrew, if your 1300 dash center has not yet been cut for a radio, don't cut it!!
If you do, I think the Gods of Fiat originality will strike down upon you and cause sudden loss of oil pressure at 7000rpm.
 
Andrew, if your 1300 dash center has not yet been cut for a radio, don't cut it!!
If you do, I think the Gods of Fiat originality will strike down upon you and cause sudden loss of oil pressure at 7000rpm.

Wow that is one vindictive God.

In regards to the gauge, honestly I think the accuracy of a street driven car's gauge is rather moot. A gauge gives you an indication of what is happening, when you are driving you are not checking to see if it is 22 or 25 lbs, you are looking to see if it is in the right range for the engine speed. It is about relativity of what is happening and not exactness unless you are bored sitting at a light and need something to obsess over.

If I was running a race car I would want a really accurate idiot light to go with a good gauge to look at after I had pulled over... You don’t have time to look at a gauge, actually read it and correctly interpret it at speed. A recent incident with water pump on an 850 Sport Coupe where despite a gauge and a poorly placed idiot light the driver failed to parse out the problem in time to save the engine from overheating. No it wasn’t me.
 
I used a VDO (Volvo- supplied) sender with the Fiat gauge. They come in different Bar ratings. The gauge is as accurate as one may expect from a factory gauge, just inverted. To resolve that, I reproduced the gauge face reversed.

X19-0006d.jpg



X19-0281.jpg
 
I might go about getting the dash volt meter swapped. Mine always reads 16V and red anyways. I haven’t been able to diagnose that one yet.

Speaking of which how do you test to make sure the idiot light is working properly?
 
you MAY run into clearance issue to the breather cyclone with something as large as the dual VDO unit

BTW engine looks neat!

SteveC

You may be right on the clearance issues coming from up there. Also what’s the difference in signal between this high location and down by the oil filter?

Thanks, hopefully the cleanliness and paint last.
 
Last edited:
You may be right on the clearance issues coming from up there. Also what’s the difference in signal between this high location and downy the oil filter?
Thanks, hopefully the cleanliness and paint last.

If you can make an adaptor, the upper location does work with the 'bell' housing sender. I offset it that way to clear the FI piping. No difference in pressure reading, the lower port is of course closer to the source, but that doesn't mean much of anything.

X19-OPgauge-Sender.jpg


My ('87) 1500 block had the lower port filled with a 'slug'. Others have said their blocks don't have it

X19-0528.jpg
 
Instead of making the adapter why not use something like this, https://www.pegasusautoracing.com/document.asp?DocID=TECH00129 and further isolate it while placing it almost anywhere you want (on the front side of the engine that is). I don't thing gravity plays a major part in this so it could be brought upwards for easy access, or downwards either way. I believe also any SS brake tube would do. If it can stand up to hot brake fluid, it should be able to stand up to hot oil. This site sells a M14x1.5 adapter as well.

I will sit in the car and figure out what I want to do for my gauges. I could fab up a cup holder mount out of wood or SS which I have plenty and put both the wideband and oil pressure there. It would also hold my choke lever instead of it just poking through the carpet at the hand brake. That's if I cannot get them to fit where the ash tray goes, easy cutting and relatively easy to replace should I want to.
 
The wideband gauge is something you need to monitor pretty closely, for instance to see how the AFR changes over the rev range.
To be able to look at for a couple of seconds, it really needs to be right in front of you.
Down by the choke lever probably won‘t cut it.
 
For that matter, ANY gauge worth mounting should be in easy eyesight to at least check without distracting from your driving.
 
Back to what Steve said above...the European gauges with an oil pressure gauge, did they use a sender like the twin cams (‘74-back & 85.5 maybe for US market?) or something else ? (Apparently a something else that Lada picked up)
 
Apparently a something else that Lada picked up
I'm not sure the answer to your question. But these are the only oil pressure items I found on the Lada parts site:

https://ladapower.com/catalog/niva-1600/electric/lada-niva-oil-pressure-warning-lamp-sensor-detail
https://ladapower.com/catalog/niva-...il-pressure-sensor-to-gauge-cursor-oem-detail
https://ladapower.com/catalog/niva-...oil-pressure-sensor-t-branch-connector-detail
https://ladapower.com/catalog/niva-...2121-2101-2103-2106-oil-pressure-gauge-detail

Looks like there are two separate senders; one for the warning light, and another one for the gauge. And a "splitter" fitting to mount both in a single hole.
 
Back
Top