Oil Pressure Sender

Now I have the Chinese dual oil pressure sender in place. I can verify that the "idiot port" is M14/1.5. Jeff, you are right. The Veglia oil pressure gauge is reading backwards but is showing pretty accurate. This is at least better than nothing and I will get used to it, just like I did with the tachometer ;-)
 
Bjorn Nilson said:
I will get used to it, just like I did with the tachometer
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Ha, I never thought of it but having ALL of the gauges sweeping backward would be fun. :)

After thinking about it, I believe it is the various coolant temp sensors that come in different fitting sizes. Sorry for any confusion.
 
I couldn't even figure out how to see the item's listing. I guess it requires registration and download a app? But I have no intentions of doing either so it really doesn't matter.

However the same type and price range of senders can be found at AliExpress.com. It is sort of the Chinese version of Amazon. Site is secure, no registration, and has proven very reliable to me. In the rare event of a error, their customer service is superior to eBay, etc. And shipping from China can be faster than from across town in many cases.
 
Dr.Jeff said:
I couldn't even figure out how to see the item's listing. I guess it requires registration and download a app? But I have no intentions of doing either so it really doesn't matter.

However the same type and price range of senders can be found at AliExpress.com. It is sort of the Chinese version of Amazon. Site is secure, no registration, and has proven very reliable to me. In the rare event of a error, their customer service is superior to eBay, etc. And shipping from China can be faster than from across town in many cases.
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Wish is just another Ali Express. Swedish Post Authority have a contract with Wish that make the purchase quick and easy. Purchasing from Ali Express is a complex process here, with added costs for customs fees etc. Most likely, there are no differences between products from Wish and Ali.
 
lookforjoe said:
How in Earth did you get the correct bar rating? The site link doesn't provide any specifications and the reviews are generic blather, probably not even for that item :D
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I think it is mentioned somewhere in the workshop manual that normal oil pressure at 3500 rpm is 4 bar and that is what the gauge is showing. As the gauge is showing backwards it shows 6 bar at idle speed (2 bar in reality).
 
Bjorn Nilson said:
Wish is just another Ali Express. Swedish Post Authority have a contract with Wish that make the purchase quick and easy. Purchasing from Ali Express is a complex process here, with added costs for customs fees etc. Most likely, there are no differences between products from Wish and Ali.
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Interesting. I guess things will vary from country to country. I've been fortunate and never had any problems buying from China. Also haven't had to pay for customs, taxes, etc. But our current president is working on changing all of that. :(
 
In answer to your question about the stock senders, they start at about 350 ohms at zero psi and go linearly DOWN to zero ohms as the pressure increases. This is opposite most other senders. I have bench tested 2 aftermarket "stock" senders that work with the original gauge on my '76 X/19. They always read low on the stock gauge in the dash. The sender looks linear (ie 175 ohms at 55 psi, 350 ohms at 110 psi) but the gauge is NOT linear and reads about 30 psi at 175 ohms. I put a transistor inline with the sender to increase the electrical signal to the gauge and it improved the readings BUT i did all my calculations on a bench and I think as the sender heats up, it increases its resistance. My gauge went from a cold reading about 30 psi with just the sender to 55 psi (at 2500 rpm) with the transistor driving the sender. When it is hot, the pressure goes down to about 40 psi. The mechanical gauge reads about 10 psi higher. This was the best I could do while having the gauge read zero before the engine starts.
 
Peter's account may very well explain why the stock dash gauges on many of these (well, all of mine) cars are not at all accurate. I'm sure the senders have been replaced a few times over the years with aftermarket units. Add to that wires that are old, connectors that are bad, and possibly even gauges themselves that are less than accurate. I'm not sure if there is a reliable way to get consistent accurate readings from the stock set up?
 
Well, what is the real requirement that we have of the oil pressure gauge?
In most case it is just that it shows us that "something is different to how it normally is", i.e. oil pressure is lower than normal as an alarm signal.
Do we need an accurate reading in psi?
 
Ulix said:
Do we need an accurate reading in psi?
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Only if you are OCD like me. :D

Good point though.

Although I've found the gauges on mine are SO far off that I really do not feel at all confident about anything they say. I sort of wonder, if the accuracy is that bad, then is the reliability (repeatability) also bad? In other words, did the pressure actually drop or is the gauge just acting up? Plus if the engine is not 'fresh', then the pressure will go up and down with differing circumstances (especially in a extremely hot climate), and it can read dangerously low at times...but is it really that low? How much creedence should I put into it, and how strongly should I react? Hard to say when I am not confident in the readings.
 
Ulix said:
Well, what is the real requirement that we have of the oil pressure gauge?
In most case it is just that it shows us that "something is different to how it normally is", i.e. oil pressure is lower than normal as an alarm signal.
Do we need an accurate reading in psi?
Click to expand...

I am with you from back on page 1 :)
Oil Pressure Sender
 
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