Home » Mercury Maurader Owners Figured Out That Their Oil Pressure Gauge Is Lying, And They’re Not Happy

Mercury Maurader Owners Figured Out That Their Oil Pressure Gauge Is Lying, And They’re Not Happy

Mermon Mara Gauge Top

I bet you thought I forgot about Mercury Monday, right? Just because it’s been a while since I’ve actually bothered to do one, and you may be one of those weirdos who doesn’t consider Wednesday Monday just because it’s “a different day” and “not Monday” or some other pseudoscientific crap like that. Well, you’re wrong! Because here’s an all-new Mercury Monday, and it’s a special one, because instead of focusing on a whole, entire Mercury, I want to just talk about one strange detail of the third-gen 2003-2004 Mercury Marauder: the oil pressure gauge. It’s strange because the consensus seems to be that this oil gauge is a dirty fake.


Go ahead and take a moment to wipe down your screen after what I assume was a powerful and loud spit-take. But yes, fake. The oil pressure gauge is a fake. Before we dig into what and why, allow me to refresh your memory about the Mercury Marauder, essentially a Crown Vic cop car all murdered-out with a 302 horsepower 4.6-liter V8 and some custom bumper skins and other trim.

The whole goal of the Marauder seems to be trying to look as menacing and as aggressive as possible, complete with some kinda embarrassing-in-hindsight quotes:


I especially like that the sentence they felt was important enough to put in bold type is the one that said “the taillights, turn signals, and back-up lights are smoked as dark as the DOT will allow.” Damn, Mercury! What a badass! Look at you, almost breaking the law, you’re so bad, making your important signaling lamps as dim as the law will allow! Holy shit! I bet a badass like you also drives right at the motherfucking limit of speed, right? If that sign says SPEED LIMIT 65, you know a Marauder driver is right there, not some candy-ass toodling along at 63 or 64!


That, plus “penetrating beams of light ‘let em know trouble’s comin'” and a “Debossed Marauder Name” on the rear fascia to let people know they’re “about to be blown away” (though if they’re seeing that on the rear, haven’t they already been blown away?) and exhaust pipes that emit an “authoritative note that demands respect” all add up to a formula that let Mercury really attract those younger buyers. How young? Well, the average Marauder buyer was a near-infantile 51 years old, barely past the half-century mark, compared to Grand Marquis buyers who were an ancient 69 (noice) years old! These crazy 50-something teens in their Mercury Marauders, with those dim taillights and authoritative exhaust!

Oh yeah! Plus look how much this beast would scare wimpy little Corollas and Saturns!

Oh damn! I bet you’d like to see something where the camera whips around a lot more though, right?

If that’s not enough for you, get this: the Marauder came with a black leather jacket. You know, like the Fonz, that fictional middle-aged guy who lived over the garage of that suburban family’s home on TV decades ago?



Man, were the early 2000s just crammed full of dangerous, cool 50ish men in leather jackets with zipper pulls featuring the Roman messenger god, making all kinds of trouble and giving late ’40s to early ’50s women their last real pregnancy scares? Maybe? I don’t really remember.

I need to focus here, though: see those two white-faced gauges there? That’s what I want to talk about. They must have been pretty important to the whole Marauder experience, because they get two separate callouts in the same Marauder brochure. Here’s the second one:


There they are again, number 14 this time, the Auto Meter™ gauges that will help you, apparently, take back the mean streets by keeping you informed about your oil pressure and alternator output. Here’s how the owner’s manual described the use of that oil pressure gauge:


Okay, so, help me out here. If the pointer drops below 4–60 psi or 6 psi, stop the engine as soon as possible. Sure, that’s basically fine, but why add the “or 6 psi,” because if you need to cut off the engine when the pointer drops below 40-60 psi, then why would you even need to mention turning off the engine at 6 psi which is, if my math is accurate, less than 40 psi already? That’s weird, right? Something feels off.

Well, it seems there is something off, and it’s referenced in a number of enthusiast forums about the Marauder: it’s not really an oil pressure gauge. So what is it? The consensus seems to be this, as stated by a user on the MercuryMarauder.net forum:

“The OEM oil pressure gauge is a fake. As King Fubar said, as long as you have more than ~6 lbs of pressure, the switch (it’s not a sender) closes and you get a “normal” reading on the gauge, which is around 60 lbs, IIRC. “

Essentially, the gauge is a more mechanical and visually interesting idiot light, as the oil pressure sender is not actually sending a stream of oil pressure data, but rather a simple on/off signal if the pressure is above the 6 psi minimum, which just sends the needle to the middle position, about 40-60 psi. But, it really could be anything above 6 psi. This bit of hand-waving does seem to have made some Marauder owners quite cross indeed:

I recommend insisting that these bull-s**t guages
be fixed. As far as I’m concerned my oil guage is broken. It does not tell me the OIL PRESSURE. What kind of oil pressure guage does not display the oil pressure. Complete horse-hockey!

Hey, hey, buddy, language! We don’t use salty talk like the horse-H word around here! I know you’re hurt and confused, but children read this site!

Marad 1

In fact, some people were so upset they reached out to the gauge supplier, Auto Meter, to find out the truth about the gauge. One owner shared the response they got from Auto Meter:

Dear Wayne,
Thank you for your question. I understand you are disappointed to find a gauge that appears to be an Auto Meter gauge, yet functions as a typical original equipment (OE) piece.

Auto Meter Products built the Marauder’s gauges to Ford Motor Company’s specifications while borrowing from the look of our Ultra Lite instrument line – that’s why they function like an original equipment (OE) gauge, but look like Auto Meter’s Ultra Lite gauges. The gauge is not ballasted. Rather, as you indicated, it operates more like an “on/off” switch.

Although your idea of a conversion kit for your Marauder’s oil pressure gauge is logical and inventive, we will not be manufacturing a conversion kit for it. As it is built to Ford’s OE specifications, the gauge cannot accommodate such an adaptation.

We are not licensed to manufacture any look alike gauges, even on a “one off” basis, to match the stock Marauder instruments.

If you desire to completely replace your stock oil pressure gauge, I’d first check with your local Ford dealer regarding warranty issues. Additionally, removing OE senders/gauges will send error messages to the car’s CPU, causing flashing “service engine soon,” or other warning lights. This can be problematic and frustrating. Again, please consult your certified Ford dealer to discuss warranty issues before replacing any of your OE senders and/or instrumentation.

The optimum scenario is to complement your OE gauges with functioning Auto Meter product. Again, you are advised to contact your local Ford dealer to determine if you’ve adequate ports, clearance, etc… to tap into your vehicle’s engine. If you would like to receive an Auto Meter catalog, please reply to this email with your full name and mailing address. I’d be happy to send you one!

I hope I’ve answered your questions. Thank you again for your email and your continued support of Auto Meter Products.

Brett Littlefield

So, it appears that Auto Meter themselves admit that it’s just an on/off indicator as opposed to an actual gauge. As for why  an automaker would do this, my assumption would be why automakers do so many weird things: it saves some amount of money. There’s no question a simple on/off oil pressure switch is cheaper than an actual sender. But there’s an aspect to it I hadn’t considered, which our own Huibert Mees, an automotive engineer who once worked for Ford, explained to me:

I think you will find Ford is not the only one using gauges as glorified idiot lights. Most people do not understand that oil pressure varies naturally and would complain that the gauge was all over the place. Ford “fixed” it by making the gauge sit in one place until the pressure exceeded a level either low or high at which point the gauge would move.

[Editor’s Note: I worked on the cooling system of the Jeep Wrangler JL, and can tell you that I sat in on a meeting during which we decided how the gauge would behave based on coolant temperature. Yes, “decided,” because the gauge didn’t just go up when things got hot and drop when things got cool, it behaved in a way that reduced the chance of the customer being concerned — for example, it might stay in the “normal range” during a short spikes at, say, a red light at the top of a steep hill that someone towed a trailer up. Was the temperature higher than normal? Sure. But you wouldn’t know it based on the gauge. -DT]. 

I suppose this makes sense, but it’s really just disappointing in another, perhaps less expected way, and implicates the customers as well as the company. It does seem to be possible to add proper, functioning oil pressure gauges to your Marauder, and most of those forum links give instructions how to do that, since it seems many Marauder owners are just not going to put up with that kind of bullshit.


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The Mercury Bobcat Was A Lesson In The Barest Definition Of Luxury: Mercury Monday (On Friday!)

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82 Responses

  1. I miss the oil pressure gauge in my ’86 IROC that would randomly – and suddenly – drop to 0 psi out of nowhere. Oil pressure didn’t *actually* drop – just flick the cluster and it’d bounce back up to where it was before.

    1. Came here to say this. NA for sure, not sure if the newer ones were like that too or not though. But yeah, Miatas have the same switch powered oil “pressure” gauge

  2. On my GM, the temp gauge, and the digital temp display in the trip computer, are almost certainly reporting accurately. They both tick up if there is a long uphill grade out west, or if sitting dead in traffic on a hot summer day. They also tick down a bit when driving through zero-degree air at highway speeds.
    No wonder I haven’t owned a Ford since 1985.

    1. Interestingly, I’m fairly certain my dad’s 2001 Volvo V70 also has a legit coolant temp gauge. After a long hard pull up a mountain road, it will definitely lean more toward the hotter side, though in California it rarely reads on the cooler side unless on cold start.

  3. My ’95 F150 as well as the two 2nd gen Ford Probes I had all had fake oil pressure gauges. The F150 at least has a real temperature gauge, on the Probes this was fake too.

  4. Crazy bout a Mercur-lie! I still see some of these Marauders tooling around, but nearly everyone is now donked out with 26″ rims on a lift with paper-thin tires and a skittles wrap over the piano black outside. Rather depressing.

  5. Of course everybody thinks that Renaultktober festivities start on the 4th, but the 3rd very much the same so long as you remember to close off some windows.

    Personally I’m looking forward to Renaultktober 25

  6. I am somewhat surprised that nobody sued over this.

    and DT, I am disappoint that you didn’t (metaphorically) fall on your sword fighting to the death (of your career) to ensure accurate temperature gauge readings be presented to the driver.

  7. I think you’ll find that almost every OEM oil pressure and coolant gauge is “massaged” in some way in order to preserve the peace of mind of the average clueless driver, who would likely be alarmed if those gauges registered the full fluctuations that occur in normal driving. In the case of my late ’80s Nissan, the signal to both the temp and oil pressure gauges pass through a resistor that severely dampens the motion of the gauges, so that only prolonged swings in readings will actually move the needles.

  8. Dude… A Maurader’s been one of my fantasy cars since the first time when I (in my mid 20’s) saw one out of the window of the retired CV Interceptor that I drove at the time.

  9. Pretty much how all modern vehicles handle their temp gauges. In fact, my mazda just has a blue light that goes off once its warmed up, not even a proper gauge.

    The NA MX-5 has a similar lying oil pressure gauge.

  10. David – ex GM_ASEP guy here. The civilian 94-96 Caprices/Impala SS models that had an analog oil pressure gauge also worked this way, they read good or bad and nothing in between. The 94-96 9C1 police cars got a functional oil pressure gauge.

  11. I feel like I heard about that a long time ago with engine temperature gauges, going from “low” to “operating” to “way too high”, rather than passing along an actual reading; but thinking about it after reading this, I (or someone further up the grapevine) had probably heard about the oil pressure gauge instead and just conflated the two.

  12. There was one guy who had a Marauder back in my home town and he’s exactly what you described in the article. Wearing that black leather jacket over shorts and black sneakers with white socks, you know, your typical 50s-ish American male.

    I always pictured the Marauder owners getting in street fights with the 7th gen Impala SS owners.

    1. You know those Marauder guys and Impala guys threw down. Tense stand-offs at the diner, racing for pink slips in the LA River. Think they made a movie about those guys…

  13. “The optimum scenario is to complement your OE gauges with functioning Auto Meter product…. ”

    Wouldn’t the optimum solution be to slide in a set of real matching Auto Meter gauges in place of these two; leaving the stock gauges wired up and hidden behind the dash so you didn’t trip out the engine management computers? The replacement gauges might not be a perfect match for the stock units but as long as they are similar and match each other most people wouldn’t notice.

  14. As others have mentioned I’m not sure why you are posting this now. Marauder owners knew it a long time ago and it was nothing new as Ford started doing that more than a decade before the Marauder came to market. It was done because there were too many people who claimed there was a problem with their truck because the oil pressure was lower at a hot idle than it was at a cold idle or driving at speed. Personally I’ve got one who’s glorified idiot light still works as designed and one where the movement was replaced with an actual Autometer gauge and sender.

    Either way it is better than the Chyrslers and their fake temp gauges which they have been using since the 80’s that read “normal” from 180~230 degrees and then jump almost directly to pegged.

    1. Forgot to mention that the Autometer guy doesn’t know what he is talking about. There are no codes or check engine light when you replace the factory gauge with a modified Autometer gauge. The only thing connected to the oil pressure switch is the gauge, the computer has no clue what is going on with the oil pressure.

  15. This isn’t unique to the Marauder, as pretty much every FoMoCo of this era has this same pressure “gauge” that is really an idiot light. Fun when the sending switch fails, and the needle jumps back and forth between zero and midscale, fluttering like a bird’s wing.

    1. Well most of the Fords from this era do have real pressure gauges, using the same movement as used for the fuel and temp gauges. They just fake it into being a glorified idiot light by inserting a resistor in the circuit between the gauge and the oil pressure switch. So it is interesting that Autometer made a dummy gauge instead of putting a resistor in that is the value needed to display the desired reading.

  16. Torch, you can have Mercury Monday whatever day you want. I’ll only be cross if Oldsmobile October isn’t promptly delivered sometime next May.

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