digital oil pressure gauge?

anyone know if a digital oil pressure gauge is digital readout/mechanical pressure measuring or digital readout/electronic pressure measuring? need something that won't accidentally fill the floorboard up with oil (had that happen with an old FJ40)... be a real pain in the XJ...

thanks!
stace

Check Summit or Jeg's - I know you can get gages like that from Nordskog, Cyberdyne, and I think AutoMeter's getting into Digital.

There's also Dakota Digital, but be ready to sign over your mortgage and first-born to them...

5-90

yep i've found several brands... but none go into detail on how the measure the pressure; mechanical or electronic... went thru several with the napa guy and none mentioned it...

A digital pressure gage is almost invariably electronic, with a remote sensor (no oil thru the dashboard.) This makes sense, as it prevents contamination of the display electronics and possible catastrophic electrical failure in the event the pressure seal is compromised.

Check around - many aftermarket gages use standard GM sensor curves - or even GM sensors - which makes keeping a spare handy easy (and cheap!)

If you don't keep a spare sensor around, you should at least have a 1/8" NPT brass plug handy - in the event the sensor starts to leak. This will allow you to keep oil in the engine until you can get another sensor in (but I just keep a spare sensor around anyhow - saves trouble.)

5-90

it does makes sense but we know how that can go sometimes... excellent advice on the plug, i do have a few hanging around... and if they do use a GM sensor a spare will be in my kit...

thanks 5-90!
stace

Isspro makes very nice (albeit very spendy) 270-degree sweep electronic gauges. You can order them with either mechanical or electrical senders. In the latter case, there are two wires that run from the sender to a little electronic box, and then several more from there to the gauge. The box must also be supplied with a hot and a ground. I have two of them in my CJ, one for engine coolant temperature, and one for tranny temperature. I don't know if they offer them with digital readouts or not, but I wouldn't be surprised.

Here is a link to their site showing a few choices for oil pressure gauges with elecrical senders.

http://isspro.com/products.php?cat=33

For a minute, I thought you were showing "sweep" LED gages - you know, where there is an arc of LEDs around the perimeter of the gage.

Those are sometimes done with a digital readout in the centre, and can be handy - a precise reading when you have the time, or a "quick" reading like you'd get from a needle gage in a pinch. I think Nordskog and Cyberdyne both make gages like that.

Still, I'd not heard of Isspro - where'd you turn them up?

5-90

5-90 said:

For a minute, I thought you were showing "sweep" LED gages - you know, where there is an arc of LEDs around the perimeter of the gage.

Those are sometimes done with a digital readout in the centre, and can be handy - a precise reading when you have the time, or a "quick" reading like you'd get from a needle gage in a pinch. I think Nordskog and Cyberdyne both make gages like that.

Still, I'd not heard of Isspro - where'd you turn them up?

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To be honest, I don't remember. I probably found them on the Internet. It's been several years now. I was (and still am!) looking for cooling solutions for a big-block-powered CJ with an auto tranny, and I wanted ACCURATE temp gauges for the motor and the slushbox. I liked the idea that these used electric senders AND a 270-degree sweep on the gauge face. They have worked well for me, and in my admittedly limited testing on the stove with some boiling water and a few kitchen thermometers, they are more accurate (and far more precise) than the little Autometer I had before.

Did you find anything with digital dispalys on their site (sorry, I didn't have time to search it out)? Since their gauges are electronic rather than simply electrical, I would be surprised if they don't offer a digital gauge for use wiht the same sender and black box.

Best of luck with it!

I do not believe that anyone makes a digital or electronic temp guage that does not use either a temp sender or a ECU sensor. In other words (mechanical oil line to the gauge and then the signal converted at the gauge). It is not practical!!

ISSPRO has been making guages for many years.

What do you mean by a "electric senders"?? Temp senders (brass bulb with thermister) that screws into the block, tranny, axle, etc are mechanical. They have a resistance output that is what drives the guage. On the other hand if your ECU has a temp sensor somewhere in the engine then you can use that output to drive a gauge.

Either method is just as accurate as the other. I suspect in reality you will find very little difference in accuracy in any of the aftermarket gauges as long as the sender and gauge are not damaged.

Michael

2xtreme said:

I do not believe that anyone makes a digital or electronic temp guage that does not use either a temp sender or a ECU sensor. In other words (mechanical oil line to the gauge and then the signal converted at the gauge). It is not practical!!

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Agreed. I was referring to the fact that with oil pressure gauges, you can obviously choose between mechanical and elecrical senders.

2xtreme said:

ISSPRO has been making guages for many years.

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Yup. But I just discovered them a few years ago.

2xtreme said:

What do you mean by a "electric senders"?? Temp senders (brass bulb with thermister) that screws into the block, tranny, axle, etc are mechanical. They have a resistance output that is what drives the guage. On the other hand if your ECU has a temp sensor somewhere in the engine then you can use that output to drive a gauge.

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I was referring to the fact that Isspro offers the choice of electrical or mechanical sending units for use with the same style of oil pressure gauge, even though my personal experience with Isspro had been with temp gauges only.

I had originally planned to replace all of my gauges with the same type, and I wanted them ALL to be the same (270-degree & electical senders for the pressure gauges). I had been unable to find another gauge manufacturer that offered a full 270-degree-sweep analog oil pressure gauge for use with an electrical sender. The choices were to settle for a 90-degree-sweep with an elecrical sender, or a 270-degree-sweep with a mechanical sender.

None of which is really germane to the question in the orignal post... My (very poorly expressed) point was to illustrate that Isspro's gagues are different from most in that the sender does not directly connect to the gauge itself. Instead, it connects to an electronic controller that is in turn used to drive the gauge. The fact that the gauge is controlled electronically led me to surmise that they might offer a digital gauge for use with the same controller/sender combination.

Whew! Sorry if my rambling was (or still is!) unclear.

2xtreme said:

Either method is just as accurate as the other. I suspect in reality you will find very little difference in accuracy in any of the aftermarket gauges as long as the sender and gauge are not damaged.

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Probably true.

However, in my crude testing a few years ago, the AutoMeter tranny temp gauge I bought consistnetly read 5-10 degrees higher than the Isspro and the two cooking thermometers I was using to measure water temperature in a pot on the stove. It seemed to get worse as the temperature climbed. But there was never more than a few degrees difference between the Isspro and both of the cooking thermometers once the water temperature rose above about 80 degrees, if I remember correctly.

Obviously, these are just my observations with those two particular gauges.... Not a very scientific test, and not much of a sample from which to draw sweeping conclusions. Nonetheless, I used the Isspro and left the AutoMeter on my workbench.

i was checking out all the ISspro gauges... they aren't all as expensive as the link given... nice option of mechanical or electronic... could be the way i go... still gonna shop around a bit more

rokclimbertx said:

i was checking out all the ISspro gauges... they aren't all as expensive as the link given... nice option of mechanical or electronic... could be the way i go... still gonna shop around a bit more

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I like the design, and they have the feel of quality products. They are sealed for marine use, which was a bonus for use in my CJ.

The only quibble I have is that one of the two gauges I purchased twitches now and then. By that I mean that the needle will intermittently drop about 10 degrees and then jump right back up again. This happens quickly enough that it is obviously a sensor/controller/gauge problem, not an accurate reading. Isspro happily replaced the gauge (including the sensor and the controller) for me, but the replacement does exactly the same thing. If it's an installation problem, I have yet to figure it out. These days, I don't drive the CJ much anymore (I bought an XJ a few weeks back, hence my recent arrival here), so I don't worry much about it.

My other Isspro gauge works perfectly, and if I were in the market I would probably by Isspro again.

raneil said:

I was referring to the fact that Isspro offers the choice of electrical or mechanical sending units for use with the same style of oil pressure gauge, even though my personal experience with Isspro had been with temp gauges only.

My (very poorly expressed) point was to illustrate that Isspro's gagues are different from most in that the sender does not directly connect to the gauge itself. Instead, it connects to an electronic controller that is in turn used to drive the gauge. The fact that the gauge is controlled electronically led me to surmise that they might offer a digital gauge for use with the same controller/sender combination.

However, in my crude testing a few years ago, the AutoMeter tranny temp gauge I bought consistnetly read 5-10 degrees higher than the Isspro and the two cooking thermometers I was using to measure water temperature in a pot on the stove. It seemed to get worse as the temperature climbed. But there was never more than a few degrees difference between the Isspro and both of the cooking thermometers once the water temperature rose above about 80 degrees, if I remember correctly.

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Not trying to beat this to death (sorry if it looks like I am). I am still not sure what you guys mean by a electric temp sender? Temp senders, and pressure senders are all mechanical. They take the temp or pressure and output a resistance that can be translated to the gauge as a temperature or pressure (they have electrical connectors on them but they are considered mechanical). The gauges are electrical (because the air and oil do not come into the back of the gauge. A mechanical gauge would have the oil, fuel, vacume or air line directly in the back of the gauge.

If you do see a box between a gauge and the sender it is probably a signal amplifier.

A digital gauge would be electrical and would have LED's instead of a pointer.

most gauge manufacturers that I am aware of make 270 deg gauges. However, it might be hard to get them due to distribution networks.

So, for the original post:
you want a digital or mechanical gauge (depending on what you want it to look like) and you want a sender with a curve that matches the gauge you are useing. As long as you do not get a mechanical gauge you do not have to worry about air, oil or anything else coming through the firewall.

Hth,
Michael

T'ain't necessarily so.

A mechanical sender will have a mechanical - or a fluid - connection from the sense port all the way to the gage - like the old copper or Nylon tubes on mechanical pressure gages.

An electrical sender will still have a sender (with some mechanical effect,) but the pressure sender is usually a diaphragm connected to a variable resistance (which alters a reference voltage) or a thermistor (a temperature-sensitive resistance, which alters a reference voltage.) Once you get about two inches away from the sense port, you're dealing with an electrical signal.

The OEMR oil pressure gage and temperature gage are both electric - they use sensors to create/modify an electrical signal/reference voltage to drive a gage.

Electrical gages may also be driven directly by the sensor signal.

5-90

5-90 said:

T'ain't necessarily so.

A mechanical sender will have a mechanical - or a fluid - connection from the sense port all the way to the gage - like the old copper or Nylon tubes on mechanical pressure gages.

An electrical sender will still have a sender (with some mechanical effect,) but the pressure sender is usually a diaphragm connected to a variable resistance (which alters a reference voltage) or a thermistor (a temperature-sensitive resistance, which alters a reference voltage.) Once you get about two inches away from the sense port, you're dealing with an electrical signal.

The OEMR oil pressure gage and temperature gage are both electric - they use sensors to create/modify an electrical signal/reference voltage to drive a gage.

Electrical gages may also be driven directly by the sensor signal.

5-90

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I think that we are both describing the same parts, but have a difference of opinion of their names.

The mechanical sender as you call it I have never heard called a sender before. Just a pick-up.

The electric sender as you call it I have allways known as a "sender" and they are mechanical and send a resistance (voltage should not change) to the gauge.

I think we should agree to disagree on the names

I hope that the original poster, understands what they are looking for in a oil temp guage that will not leak in their jeep!!

Michael

I can handle that - just a professional difference.

In most parts catalogues behind the counter, the part that screws in and takes the reading - electrical or mechanical - is called a "sender," then you specifiy whether it's electrical or mechanical (sometimes, you can get a new mechanical temperature sensor separately from the gage) and the electrical senders are divided again into "gage or light?"

I've just spent too much time in parts catalogues... :laugh3:

At least we're on the same page now, and everything's :sunshine:

5-90