View Full Version : Dummy Gauge?
kim300a
03-01-2009, 09:13 PM
I have notice in the MM that the oil pressure guage never moves. It holds 60psi all the time. I know that oil pressure varies with engine rpm. I have to think this is a dummy guage just for looks. Any input on this speculation?
TiTo35
03-01-2009, 09:15 PM
Nonfunctional...thats the better term for it. :D
rayjay
03-01-2009, 09:15 PM
Its really nothing more than a indication that you have pressure. There are real ones available. Do a search, there are multiple threads and how tos.
FordNut
03-01-2009, 09:19 PM
Glorified idiot light. There are hundreds of posts and threads about it. You can search on here and find detailed instructions on how to switch to a functional gauge, there are probably 3-4 different ways to do it.
Blackened300a
03-01-2009, 09:53 PM
It works on a 6psi switch so it just shows 60 psi under all temps and RPM's. The gauge and the switch work together so when replacing with a "real" gauge, the sender and gauge must both be replaced. I tried the easy way out and it dont work.
RF Overlord
03-02-2009, 08:35 AM
There's a how-to in the FAQ here (http://www.mercurymarauder.net/forums/faq.php?faq=how_to#faq_real_oi l_pressure_gauge).
O's Fan Rich
03-02-2009, 08:39 AM
Glorified idiot light. There are hundreds of posts and threads about it. You can search on here and find detailed instructions on how to switch to a functional gauge, there are probably 3-4 different ways to do it.
Hey, Brian.... you can't tell a new member to do a search... You MUST answer the question to the full every time it is asked!
Otherwise you are just like motorcitymarauders.com.......
Dragcity
03-02-2009, 11:53 AM
I say go mechanical. I did and have never had to worry about a sender going bad, or getting false readings.
CKMustangCobra
03-02-2009, 04:53 PM
I say go mechanical. I did and have never had to worry about a sender going bad, or getting false readings.
Oil line in your cab?
Dragcity
03-02-2009, 05:14 PM
It's not a cab, it's a Marauder.
I have no problem with it. Put it in at 38,000 mi and I am at 88,000 miles.
Had one in my drag car for 7 years without a single drip. And that was only a nylon line with brass compression fittings.
What are you worried about, poor workmanship? The fittings and lines they make today are practically failproof, especially at only 150 PSI max pressure. I have a stainless braided, teflon lined hose, used for brake lines.
I worry more about my heater core failing.
GetMeMyStogie
03-02-2009, 06:26 PM
Glorified idiot light.
I think it's worse than an idiot light. The CEL lights up when oil pressure drops below minimum, and it's right up top so you'll see it right away. The fake-o oil 'gauge' drops very slowly (takes a good 60 seconds to fall from 60 psi to zero), and it's not really in the line of sight. So, if your oil pressure starts running low, say, in the 3-8 psi range, no instrument will alert you to that fact. A CEL would, intermittently.
I say go mechanical. I did and have never had to worry about a sender going bad, or getting false readings.
Ditto. Plus, the full-sweep mechanical gauges are much less $$ than full-sweep electrical.
RF Overlord
03-02-2009, 07:19 PM
The CEL lights up when oil pressure drops below minimum, Not in a Marauder. There's no connection from the oil pressure switch to anything but the gauge.
GetMeMyStogie
03-09-2009, 07:45 PM
The CEL lights up when oil pressure drops below minimum
Not in a Marauder. There's no connection from the oil pressure switch to anything but the gauge.
Right. What I meant was that CEL in any other car would light up each time oil pressure drops below minimum, but in our case, the gauge will slowly drop back to zero. That, and it's positioned out of the normal line of sight while driving, unlike a CEL.
So, while you would probably notice an intermittently flashing CEL in any other car, in an MM you would probably never notice low oil pressure until the engine seized.
Hrph. Someone should point that out to Ford - no alert to low oil pressure.
Richy04
03-10-2009, 06:20 AM
If you want, pick up a real gauge and send me both of them and I will swap the faces for you and add the factory pigtail so its plug and play. You will then have a factory looking gauge that works like a real one. I did mine and it looks great. You will just have to install the autometer sender near the oil filter and you are good to go. The stock gauge looks much better than the aftermarket autometer in that it is backlit like your dash.
SC Cheesehead
03-10-2009, 06:23 AM
If you want, pick up a real gauge and send me both of them and I will swap the faces for you and add the factory pigtail so its plug and play. You will then have a factory looking gauge that works like a real one. I did mine and it looks great.
Richy,
I'm a little fuzzy on this, can you explain further; sounds like something I might want to try.
Dragcity
03-10-2009, 07:55 AM
And when oil pressure drops, you don't know if it's the pump or the sender.
Choices:
1) Shut her down, tow it home or to a shop and check to see if the pressure is really bad or the sender failed
2) Hope it is just the sender and drive it home, hope like heck it isn't the pump.
I will never know why folks are so worried about mechanical oil pressure gauges.
I put in Phantom II backlit gauges for mechanical oil pressure and replaced volts to match. I did have to put a resistor in line to dim down the LED's to match my dash lights brightness. Plus, the gauge rings are black vs silver and match the pod better.
Just my preferences, but ya'll shouldn't be so worried about a 1/8" oil line. Ferry Hydraulics here in Buffalo sells everything you need for a leakproof fit. Didn't even have to drill a hole in the firewall. Fittings assemble after you run the braided line. (bonus)
I prefer mecahnical when it comes to oil pressure. Never lies to me....
Good luck on your preferences. I know we are all different, and I've been told many time I am different, or was that 'special', maybe slow. Yeah, it was slow....
03blackmerc
03-10-2009, 08:42 AM
well thats really strange. i got back from about a 2 hr trip with my MM and i noticed the oil pressure dropped to 25PSI at idol. i was using the recomended 5W-20 oil, but the gage was deffinatly moving up or down depending on what RPM the motor was at. i changed the oil to 5W-30 and never had the oil pressure drop again, but i did not think it was a dummy switch. The gage moved in the same way as my Mustang which has the stock gage also from 1987. I dont understand why it would be a dummy gage it looks to me like it operates normally
rayjay
03-10-2009, 09:34 AM
well thats really strange. i got back from about a 2 hr trip with my MM and i noticed the oil pressure dropped to 25PSI at idol. i was using the recomended 5W-20 oil, but the gage was deffinatly moving up or down depending on what RPM the motor was at. i changed the oil to 5W-30 and never had the oil pressure drop again, but i did not think it was a dummy switch. The gage moved in the same way as my Mustang which has the stock gage also from 1987. I dont understand why it would be a dummy gage it looks to me like it operates normally
If its the OEM gage it goes to set place and stays there. Only moves when you turn the car off. Sounds like someone put a real one yours at some point.
Dragcity
03-10-2009, 09:58 AM
25 psi at idle is fine. I would keep with the 5/20 oil. Increasing oil pressure by means of thicker oils is not a generally accepted good practice. We want volume as well as pressure in this application.
Sounds like you have a working gauge there. The OEM 'switch' reads what, 65 psi? Been so long, I forgot...
My engine gets Motorcraft 5/20 blend at every change.
RF Overlord
03-10-2009, 12:42 PM
^^^what Dragcity said^^^
03blackmerc, did you buy the car new? One way to tell if you have the OEM gauge is to look at the sender...if it's small, like a "C" battery, and has a plug-in connector, then it's the OEM switch. If it's a much larger canister with a stud-and-nut connector, then it's the aftermarket (real) one.
magindat
03-10-2009, 12:49 PM
I say go mechanical. I did and have never had to worry about a sender going bad, or getting false readings.
Or oil or fumes in your passenger compartment...
magindat
03-10-2009, 12:53 PM
idol
Main Entry:idol http://www.merriam-webster.com/images/audio.gif (javascript:popWin('/cgi-bin/audio.pl?idol0001.wav=idol'))P ronunciation: \ˈī-dəl\ Function:noun Etymology:Middle English, from Anglo-French idle, from Late Latin idolum, from Greek eidōlon image, idol; akin to Greek eidos form — more at idyll (http://www.merriam-webster.com/dictionary/idyll)Date:13th century 1: a representation or symbol of an object of worship ; broadly : a false god
Main Entry: 2idle Function:verb Inflected Form(s):idled; idling http://www.merriam-webster.com/images/audio.gif (javascript:popWin('/cgi-bin/audio.pl?idle0006.wav=idling') ) \ˈīd-liŋ, ˈī-dəl-iŋ\ Date:1592 intransitive verb 2: to run at low power and often disconnected usually so that power is not used for useful work <the engine is idling>
FordNut
03-10-2009, 01:27 PM
I've replaced numerous sending units on my real gauge. I wish I had gone mechanical.
Marylandrauder
03-10-2009, 02:11 PM
If you want, pick up a real gauge and send me both of them and I will swap the faces for you and add the factory pigtail so its plug and play. You will then have a factory looking gauge that works like a real one. I did mine and it looks great. You will just have to install the autometer sender near the oil filter and you are good to go. The stock gauge looks much better than the aftermarket autometer in that it is backlit like your dash.
Are you talking about a mechanical or electrical oil pressure gauge.
Dragcity
03-10-2009, 04:32 PM
Main Entry:idol http://www.merriam-webster.com/images/audio.gif (http://javascript<b></b>:popWin('/cgi-bin/audio.pl?idol0001.wav=idol'))P ronunciation: \ˈī-dəl\ Function:noun Etymology:Middle English, from Anglo-French idle, from Late Latin idolum, from Greek eidōlon image, idol; akin to Greek eidos form — more at idyll (http://www.merriam-webster.com/dictionary/idyll)Date:13th century 1: a representation or symbol of an object of worship ; broadly : a false god
Main Entry: 2idle Function:verb Inflected Form(s):idled; idling http://www.merriam-webster.com/images/audio.gif (http://javascript<b></b>:popWin('/cgi-bin/audio.pl?idle0006.wav=idling') ) \ˈīd-liŋ, ˈī-dəl-iŋ\ Date:1592 intransitive verb 2: to run at low power and often disconnected usually so that power is not used for useful work <the engine is idling>
Oooh, Ooooh. I got it right.
Do I get a gold star teach???
GetMeMyStogie
03-10-2009, 04:56 PM
Or oil or fumes in your passenger compartment...
Only if you don't know how to work a compression fitting ;)
GetMeMyStogie
03-10-2009, 05:02 PM
Yeah! :high5:
Dragcity
03-10-2009, 06:47 PM
Man, I'm telling you, the fittings I got from Ferry Hydraulics were neat as heck. A three piece contraption that is good to 3000 psi. Guy said the hose would burst before the fitting came off. Said the racers use the same thing on their brake lines.
Really, there is ZERO chance of any leaks, if you are careful in assembly. Once together, the system is rock solid. Same stuff as used in brake lines, can't afford leaks there either, and they do a lot more work in that application.
I know I won't talk anyone into this, and that is O.K. Just please don't think I am some kind of a hack and done a barn job on my Marauder. I drive it everyday as my primary transportation. I take my Family on trips in it.
Good luck in whatever you choose.
Richy04
03-13-2009, 05:42 AM
Are you talking about a mechanical or electrical oil pressure gauge.
The autometer electrical type gauge.
If you choose to go mechanical and the face size is the same, I can most likely change that over too..
GetMeMyStogie
05-20-2009, 07:29 PM
I just finished installing a pair of ultra-lite II's: mechanical oil pressure; and electric full-sweep oil temp. I would have preferred mechanical oil temp too, but autometer doesn't make one in an ultra-lite II. Still, one mechanical gauge is better than none. As stated above, it never lies to you. And, seriously, leaks? Come on! I used one before and I like it.
I added a hole for a third gauge, and put the stock voltmeter there. After seeing them lit up at night, side by side, I think I no longer favour the original look (though the oil can and the battery symbols are so.....international)
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