Usefulness of oil pressure and temp gauges

[vinu_neuro]

I bought a SPA Technique oil pressure/temp dual gauge a few weeks ago for a great price but am now reconsidering using it. These gauges are absolutely awesome (you should see the connectors and senders). But I also don't like wasting money. I just don't want it to be something that's novel at first but then becomes something unnoticed.

Can anyone with pressure and temp gauges comment on their usefulness? As far as my oil geekiness goes, the pressure gauge seems pretty useful in monitoring viscosity changes, especially since I'm going to initially try M1 0W-40 (and hopefully stick with it) which tends to fluctuate in viscosity over an interval. Anything beyond this though?

Here's their page, they make high-end racing equipment. Got the gauge for half the price listed.

http://www.spatechnique.com/product_pages/page.cfm?cat=2

 

[JHZR2]

Personally, if I knew that my engine was healthy, Id not see the need for a pressure gauge much. A dummy light with a higher trigger pressure? Perhaps.

What I do like is the approach of providing oil temperature. My BMW in fact ONLY has an oil temp gauge, not a coolant temp gauge. There is a dummy light and power reduction due to high coolant temp, but no gauge.

To me this is smart as the fact that water is reading to temp, especially on gauges installed which do not provide a true reading, does not let you know when you truly are capable of accepting full load. Oil temperature is that determinant.

Coolant temp is really only good to give some starting figure of engine temp and to alert you to an overheating situation.

I like the blue and red dummy lights for coolant. I would love to have a cold and hot dummy light (maybe with access to the actual temp in the LCD display) for coolant, and then a real oil temp gauge. My BMW got it nearly right. With a scangauge plugged in, all the info Id want is right there...

 

[Jim 5]

Those spa design gauges are really nice. Not a cheap gauge at all, but you get 2 gauges in 1 pod.

Originally Posted By: JHZR2

What I do like is the approach of providing oil temperature. My BMW in fact ONLY has an oil temp gauge, not a coolant temp gauge. There is a dummy light and power reduction due to high coolant temp, but no gauge.


I just test drove a 2011 BMW 5er with the N55 and noticed this too. What it told me was that in my climate would take about half of my commute beforeI could get into the fun pedal (winter). I had never seen one before with only an oil temp gauge but for those who are really concerned about real world engine wear/damage, it perhaps makes more sense than a coolant temp gauge.

 

[vinu_neuro]

Afaik only N54/55 models get the oil temp gauge right? Last couple times the rentz' X5 has been in they got a 328 and 335. Iirc the 335 was the one with the temp gauge, 328 had the standard mpg meter that makes you feel guilty.

Would there be any way of getting approximate oil temp without the gauge, maybe with an IR gun? I rarely do full load on my car so if I knew roughly how long the oil takes to get up to temp in various conditions I'd be set.

 

[MrBeachcomber]

I've been using both an oil temperature gauge and an oil pressure gauge since the 1980's. Previously I only used the oil temperature gauge in my race vehicles; however, once the Corvette incorporated the oil temperature gauge into their standard display with the 1981 Model, I started using it on the street to monitor the overall health of the oiling system along with the pressure gauge.

Previously, I used the oil pressure gauge to determine when the oil was up to operating temperature as indicated by a 30 PSI drop in oil pressure to the normal idle pressure of 50 PSI before putting any real load on the engine. (I used straight 30W HD Valvoline back then in all my street engines.)

With the oil temperature gauge, I monitor my oil and short shift to keep the engine at or about 2000 RPM until the oil temperature reaches at least 175F. (I use 5W-30 Mobil 1 now.)

When autocrossing I try to maintain the oil temperature at 185-215F for optimum engine performance. On long Interstate trips, I periodically check the oil temperature to make sure I'm in the 175-205F range especially during the long trips down I-95 from Virginia to Florida.

If you tow, the oil temperature gauge is a real boon in determining how much of a load the engine is experiencing. It might even help determine if you need to add an engine oil cooler. (I also use a transmission oil temperature gauge in all my automatic transmission vehicles for the same reason.)

I guess it just boils down to what usefulness you expect from the addition of the gauges. If you watch your gauges on a frequent basis, any deviation from the normal reading may help you avoid a catastrophic situation, e.g., running 10 PSI of oil pressure at 2500 RPM or an oil temperature of 250F while cruising the Interstate during the summer, while confirming all is well if the readings remain within the prescribed range. YMMV.

 

[river_rat]

Originally Posted By: MrBeachcomber
Previously, I used the oil pressure gauge to determine when the oil was up to operating temperature as indicated by a 30 PSI drop in oil pressure to the normal idle pressure of 50 PSI before putting any real load on the engine.

Me too.
...And also to see if there was any discernable difference in after filter oil pressure to the engine on my vehicles with the various brands and sizes of oil filters that I use. There wasn't.

Originally Posted By: JHZR2
...A dummy light with a higher trigger pressure? Perhaps...

I have thought about trying to parallel two different trigger pressure OP light senders, and set it to switch the low pressure one out of the circuit automatically when the engine is above idle speed. Never had time to look into it yet.

 

[CourierDriver]

If my engine ain't knocking and radiator heat ain't rising and no steam coming out of the engine,,,I'm good. but,,,if I'm in an airplane,,u bet I want gauges,,,,but I'm never in plane,,lol,,,and Ive never lost an engine due to a faulty idiot lite either,,,I don't know,,do I need a gauge for my male ego?

 

[A_Harman]

Since I'm a by-the-numbers kind of guy, I think you should install the oil pressure and temperature gauges. I believe you will monitor them more than you think you will. There is no such thing as having too much information about how your engine is acting. As you develop a feel for how the gauges react during different driving situations, you will be able to detect potential problems sooner.

 

[MarkM66]

Originally Posted By: CourierDriver
If my engine ain't knocking and radiator heat ain't rising and no steam coming out of the engine,,,I'm good. but,,,if I'm in an airplane,,u bet I want gauges,,,,but I'm never in plane,,lol,,,and Ive never lost an engine due to a faulty idiot lite either,,,I don't know,,do I need a gauge for my male ego?


I feel about the same.

So if oil pressure is a little different due to a different weight oil, what's that prove? Are you going to dump the oil immediately if it's not to what you 'think' is should be?

Unless you're blocking off the grill for fuel mileage reasons and really need to keep an eye on the temp, or some other sort of experimenting. I think if the vehicle is in decent shape, it's current systems will keep the car in check just fine.

 

[GMBoy]

I love gauges, the more the better. Each one serves a purpose as a "window" to what's going on underhood.

 

[calvin1]

A light (or a three position "gauge") can only tell me two things: Good Enough or PANIC!. When it's -10F before the 20MPH wind in the dead of night and my a light comes on I'd REALLY like to know if I can limp home or not. With a gauge I can make that decision - or even change it if things deteriorate - but with a light I don't have any way of knowing.


An added benefit to an oil gauge is it can tell me if my oil is up to temp and it's safe to drop the hammer or not. Of course an oil temp gauge would do that even better but it's like wishing for the moon just to get the pressure included standard.

 

[hooligan24]

I use both oil presssure and temp gauges in my Neon. I installed them because I use the car on Road Course race tracks. For street use, I like to use the oil pressure gauge to determine when to start driving the car after starting it up. I like to wait until idle oil pressure is 50psi or less because when I start to drive, the oil pressure will shoot up into the 90's. The oil temp gauge is mainly for when I hit the course, but it also helps me decide if I need to let the engine idle a little bit to cool the turbo down some before turning off the engine. I have had the gauges long enough that I can predict what they will read without looking at them. Anything outside of my predictions will show me that I have a problem somewhere. Twice now, the oil temp gauge has helped me catch a sticking brake caliper, once on the racetrack and once on a daily commute down the freeway. With the sticking caliper, oil temps went up 30 degrees higher during one session on the track compared to the previous session. I would have never known until a few days later because smoking brakes on the track are a normal thing. When I caught it during the daily commute, oil temps went up 15 degrees compared to normal. I got home and got out my infered temp gun and started shooting brake rotors, one of the rear rotors was almost 300 degrees hotter than the other side. Caliper was dragging and causing extra load on the engine.

My engine is equiped with an oil/coolant heat exchanger, so temps dont fluxuate much. One thing I have noticed though, thinner oils take longer to warm up, and they cool down quicker than thicker oils in my engine. It also showed me that my oil takes a lot longer to get to operating tamps compared to the coolant.....sometimes upwards of 8 miles longer on the cold days of winter. I find the gauges as a pair, very useful. I also have a boost/vacuum gauge. vacuum gauges can be useful to help notice a vacuum leak, and also be used as a fuel saver. More vac=less fuel usage.

EDIT: I forgot to add to my already long post. The Dodge 2.4L has a problem with the stock oil sending unit to go bad and trigger the oil light. I read about it all the time on a car specific site. Most times, the kids driving these cars ignore the light and keep driving(stupid), and some pull off and call a tow truck only to find out later a $30 sensor went bad. In both situations, the oil pressure gauge could either save their motor or save on their wallets. No tow truck, or actually know if they have oil pressure or not.

 

[Quest]

in my case: my engines are pretty much bone stock and does not require any serious oil temp monitoring.

I would insist in having a Voltmeter to monitor charging and battery health instead (which I'm intimately familiar with). Analogue meter works wonders in this case.

I hate being stranded due to alternator charging issues or weak battery, or combination of both.

Q.

 

[mechtech2]

An oil temp gauge is my #1 choice.
But in reality, pressure and temps will be predictable after a few weeks of monitoring.
Until.... things go wrong!

A hard summer pull may show elevated oil temps that would let you know to back off or cool things down. Maybe use a thicker oil.

 

[river_rat]

Originally Posted By: calvin1
...and my a light comes on I'd REALLY like to know if I can limp home or not. With a gauge I can make that decision - or even change it if things deteriorate - but with a light I don't have any way of knowing.

The way I figure it, if the light is on at all, I shut down.

Although some old VW vans it was called normal for the light to flicker on at idle after a hot pull. If it went out when raised above idle speed, it was OK. So there can be some indication...
If that light was still on above idle...then what, 3-4 psi at maximum? Shut her down.

 

[unDummy]

The light is on, shut it down. Hope the lights works. Ever test it?

The idiot light varies with turn on pressure. Every auto maker is different. I've seen factory service manual where light doesn't turn on until
A real oil pressure gauge is nice. Oil temp is a must if you're habits require it to be monitored.

 

[hooligan24]

Quote:
I've seen factory service manual where light doesn't turn on until div>


Yep, the service manual for the turbo'd 2.4L shows that the light should come on at less than 4psi. Also, normal pressure range is 4psi-84psi.

 

[morris]

a oil pressure gauge should be plumbed with steel brake line tubing. if you use somthing else you WILL have trouble, been there done that, you dont want to hear the story. back in the dark ages i was at the drag strip Mr. Gene Snow had his funny car there. i saw he didnt have ANY gauges. i ask why, he said "i ant got time to read."

 

[MarkM66]

Originally Posted By: morris
a oil pressure gauge should be plumbed with steel brake line tubing. if you use somthing else you WILL have trouble, been there done that, you dont want to hear the story. back in the dark ages i was at the drag strip Mr. Gene Snow had his funny car there. i saw he didnt have ANY gauges. i ask why, he said "i ant got time to read."


Electric oil pressure gauges just have a sending unit and a wire to the gauge. No line filled with oil.

 

[SteveSRT8]

almost any modern car made in the last several years will automatically pull spark when the oil pressure becomes too low.

Can anyone tell me the last time they had an oil pressure related failure? They are awfully rare these days.

Gauges are great, but they're not a 'need', they're a 'want'.

I love to cycle through my EVIC in my car. I can get oil pressure, oil temp, coolant temp, etc. But you could drive the car just fine without it.