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View Full Version : Zero Oil PSI - Need a better warning indicator



DennisG01
02-20-2007, 20:42
Well, i'm sure it was my fault for not tightening it correctly, but one of my oil lines that I used for a remote oil filter relocation popped off from the fitting while I was driving. I used SS braided line and AN fittings from Summit Racing. I think I got lucky, though, as I took another car and back-tracked to find out where the oil originally came out (clearly seen on the road!). Turns out after the oil line popped off, I drove for about 3 - 4 minutes at, or close to, idle speed. Then about 3 minutes at up to 20 MPH (light acceleration). Then the engine started making puffing sounds and I was getting some black smoke out of the tailpipe. I looked at the gauges and the "check gauges" light was on (it sure ain't that bright, though) and my oil PSI wa at 0. I killed the engine and coasted to a stop where I then had it flatbeded to my house. I "THINK" the engine will be alright. Any thoughts?

Second part to this is I would like to add a buzzer (something like a small piezo from Radio Shack, or the like) so that if the oil PSI drops below a set amount it will sound off. The puffing sounds were very faint. Any ideas on an easy way to make this buzzer thing happen?

moody
02-21-2007, 00:57
your truck should have a oil presure switch that shuts down the electric fuel pump when the oil pressure drops off. just a thought

Arlie
02-21-2007, 01:03
This hits a hot button for me. The factory oil cooler lines have a quick disconnect famous for popping off (still makes me mad no recall was done). :mad: My 6.5 was one of the many casualties.

My wife was driving, as near as I could tell, a distance similar to what you describe. There was still some oil making an ominous trail onto my driveway.

The fuel pump is supposed to shut off killing the engine when pressure drops to zero but apparently this nice feature does not work.

I fixed the line, put oil in, fired it up twice for 10 seconds or so and got no oil pressure. I then figured out how to prime the pump using a 1/4 drive extentiion and a drill, and got pressure. The engine ran fine after that...

... for a couple hundred miles, then siezed while my daughter was driving it. :(

I hope yours is fine and I don't intend to scare you, but get some advice from the folks here about how to check for damage.

Arlie

Shikaroka
02-21-2007, 09:16
your truck should have a oil presure switch that shuts down the electric fuel pump when the oil pressure drops off. just a thought

Well, the IP can still pull a little fuel from the tank, so even if the LP quits working the truck can run for a while.
How about running the Fuel Stop Solenoid off of the same OPS?

moody
02-21-2007, 09:16
I was actually thinking you could wire the buzzer to the oil presure sender that shuts off the electic lift pump. these trucks will run without the electric lift pump.
I think they shut down that pump in case of truck is in smash-up and the keys are left on with the fuel line running ruptured. Fuel all over crash sight bad for footing.

Hubert
02-21-2007, 10:45
I am sure this device low oil pressure warning buzzer is on the market already. A lot of heavy equipment has one. Turn key to run and buzzer sounds until engine cranks starts and builds oil pressure.

Having said that I have seen lots of stuff but when I get around to trying to find one its harder than I ever imagined.

jspringator
02-21-2007, 10:46
The guy that installed my upgraded lines put them too close to the exhaust manifold, and they burned in two while crossing the WV mountains. Smoke is one heck of an early warning system! Looked at the guage as I was shutting it off and still had oil pressure.

JohnC
02-21-2007, 12:37
The oil pressure switch is not intended as a safety shutoff in the case of a loss of oil ppressure. It fullfills a requirement that any non-engine driven fuel pump must shut off automatically if the engine stops running.

Wiring a buzzer to the lift pump circuit would work well and also provide a warning should the lift pump circuit fail.

I hope your engine is OK. If you want to check it, I'd drop the oil pan and check the rod bearings. I'll bet they'd be the first to show distress.

I know a guy who drove a turbo charged gas engine 45 minutes over a period of 2 days after the oil light came on (Don't ask: wasn't me!). The bottom end was trashed but we salvaged the cam and turbo. Center main got so hot the block had to be align bored.

DennisG01
02-21-2007, 13:24
Thanks for the quick responses, guys - much appreciated. "Checking the rod bearings": I'm not sure what to look for if I do it myself (other than something obvious) so it may be worth it for peace of mind to have a shop check it out. There is a local shop that I like.

After reading through your responses about the buzzer being a good idea and that there should already be something on the market, I said to myself "you're an idiot - your boat's engine (Mercruiser/Chevy 305) has a buzzer that goes off when the oil pressure gets to low. Duh!" I'll check into that first to see if it can be adapted. One of my jobs is working at a marina, so parts shouldn't be that expensive.

Warren96
02-22-2007, 14:26
.....that would drive me nuts listening to that every time i had to wait for the glow plugs to go out. Personaly i will be installing a light mounted above the speedometer, to tell me if the oil presure goes away. Hmm... wait a minute.How about two lights above the speedo,one for oil psi and one for lift pump psi!

DennisG01
02-22-2007, 16:49
That's true - I'll definitely have to check into how it works with my boat's engine and if it can be adapted to the 6.5 (I think the pressure sensor is screwed into a port somewhere). If I turn the key on, but don't start the engine, the buzzer sounds for about 2 seconds, but then stops. Must have something to do with only working when the engine is running.

Here's an inexpesive kit (with a light) that I found at Summit Racing. I'm not quite sure how it hooks up, though. There may better things out there, but this was the first one I found.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=REB%2D140%2D1280&N=700+115&autoview=sku

john8662
02-22-2007, 17:01
The switch kit above would work.

There are other options.

You could wire a 12v buzzer to the bulb in the instrument cluster for the "check gauges" light, that would be the simplest.

Just tap one of the bulb leads off the instrument cluster, the other a ground.

So, has the engine been starting again since the incident?

J

Hubert
02-22-2007, 18:05
keep us posted about the marine system. Lots of ways to do it. For example tie into LP go to a NC power to open switch in a circuit battery buzzer ground. On your 98 LP powers at wait to start for a little while so you would not get constant buzz at WTS. Might get a buzz on extended glow??? I wouldn't mind a 2 sec buzz that checks circuit works.

FYI Lawsonproducts dot com has lots of oil pressure switches normally closed or open and at different psi's. Not the cheapest source but lots of generic parts.

On edit get power source for buzzer thats hot with key on run. Oops what I typed would buzz all the time the truck was off.

DennisG01
02-22-2007, 18:28
Good information, guys - thank you. Keep the info/ideas coming - the more the better! That's what I love about this site - good, QUALITY information!
I've pulled/checked/reinstalled all hoses/fittings, but won't actually finish up until Friday night or the weekend. Heck, the truck was due for an oil change, anyways!
Hopefully I can check into the marine system a little more when I'm at work on Saturday.

a5150nut
02-22-2007, 23:53
Check this http://www.fwmurphy.co.uk/pdf/00-02-0031.pdf

It's for a Muphy Switch. Second page has different pressure ratings. Didn't see any pricing. If not this switch you could use a double pole double throw as you would to run th LP from the OPS. Use the NC leg to operate the buzzer and maybe a lead from the GP relay to cancel operation during glow cycle. Or check Onan or Honda to see what they use for a low pressure switch.
I looked in McMaster Carr, WW Grainger and JC Whitney but Goolge found this.

Shikaroka
02-23-2007, 08:21
I think what would work well, and be pretty easy, would be to use a relay.
You could power the realy off of the lift pump circut, which would keep the relay open. When the power to the lift pump dropped, it would close the relay, and send power to a buzzer.
The lift pump gets it's power from a relay at startup and then switches to the OPS when the engine is running.
This way, you may only get a little buzzing if you didn't start the engine quick enough after the glow plugs shut off. So, it would also let you know it's ok to start.
I have been thinking of this for a few days, but I may try this out soon.

DennisG01
02-24-2007, 19:56
Well, I rechecked all of the remote oil filter hoses and connections/hose ends apart and made sure they were tight and changed my oil filter while I was at it and put fresh oil in. I hoped for the best and turned the key...click click but no turning over. Turned the key off for a few seconds, tried again...same thing. The third time I held the key on for about 2 seconds and heard another click. Went around to the front of the engine and the passenger side battery cable that goes to the starter was no longer connected. The cable itself was hot and the side post connection had broken between where the mounting bolt attaches to the battery and the clamp that holds the cable in place. Man, never seen that before! I guess I'll be chaning the cables over to top post a little quiker than originally planned.

Anyways, I had it towed to a local garage as this seems like it's getting out of my control to fix it. I'm hoping it's just a freak coincidence and the starter is bad.

As far as the warning buzzer goes, the mechanics at my marina seemed to think the idea of wiring into the "check gauges" light would be the simplest thing, but I'm interestes to see how some of the other ideas mentioned above pan out. We didn't really get into talking about what it would take to adapt the Mercruiser/marine system to a truck as this other way seemed so simple.

I checked my Chilton's book, but it doesn't have that much in the way of wiring schematics. Anyone know what color the wire is for a '98 that goes to the "check gauges" light and where would be the easiest place to tap into it?

Arlie
02-24-2007, 20:51
Seems to me you are onto the simplest solution. Another idea would be to use an existing buzzer/beeper by just running a wire from the check guages light to it's circuit. I know on the 2005 trucks warning lights are activated by grounding (power is constant). If the buzzer functions this way as well it would be an easy thing to provide the buzzer with a connection to the warning light ground.

Arlie

a5150nut
02-25-2007, 11:34
DennisG01,
I've had my dash apart and you can remove it fairly easy. It is just a large prited circut board. Trace the circut from the SES lite back to the plug and you should be able to determin whitch wire is the triger.

Another Dennis

Arlie
02-25-2007, 12:10
I looked at alldata diagrams for 1995. The "check gages" circuit appears to be on the pc board only (no wires to tap into unless you're into pc work).

The relay idea seems the best option since the oil pressure switch is open with pressure below 4 psi.

The seat belt buzzer is suitable as it functions only with the ignition in run/bulb check/start. It operates for 5 seconds when the driver seat belt is unbuckled (switch closes to ground). It's in the audible warning module which plugs into the convenience center under the dash to the left of the steering column. There are pink, gray, orange, yellow, light green, black, and black with white stripe wires connecting.

The black with white stripe connects to the seat belt switch. If you connect this to a relay thats closed to ground unless power is applied by the oil pressure switch you'd have a 5 second audible warning when the oil pressure drops. (free except your time!)

Arlie

Beedee
02-25-2007, 14:50
I have found that most of the time, that by the time warning goes off with 0 pressure the damage has been done. The idea of the murphy switch is a good idea, we use them on some of the big stuff, but I personally like the Murphy SWICHGAGE. It is an oil pressure gauge that has an adjustable switch that you can set to what ever pressure you want. If you were to set to say 20 psi, if you had a oil problem, the alarm would go off before you killed your engine. I have run these for years in the bush, great product.
We also have used the same in a temperature version, wired in through a module that shuts engine down for either problem. , Simple, tough, easy to wire in can't ask for more then that. Put your own alarm system in, light, buzzer, bell, what ever you like and your good to go.
Hope this helps.
http://www.fwmurphy.com/products/pressure_vacuum/20p_25p.htm
Try this link for more information.
Brian

Arlie
02-25-2007, 16:38
The adjustability is very attractive, maybe even indispensable if as you say, the damage is done by the time pressure is very low.

The downside is that installation is much more involved. There's a gage and pressure tubing to connect somewhere.

Arlie

NH2112
02-25-2007, 18:22
One thing to remember with the SwichGages is they work when starting, too, so you'll need an override switch to bypass it till oil pressure comes up.

john8662
02-25-2007, 23:39
I hoped for the best and turned the key...click click but no turning over. Turned the key off for a few seconds, tried again...same thing. The third time I held the key on for about 2 seconds and heard another click.

Before you had it towed you could of removed the serpentine belt, then removed the crank pulley (4 bolts). Then attached a large socket to the crank balancer bolt and tried to turn over the engine by hand. If you could turn over the engine then you'd know it was electrical in nature, if not, then internal damage is likely.

Keep us posted.

J

Hubert
02-26-2007, 07:43
So do the murphy switches give you a few seconds of reaction time? Personally I don't like the idea of the engine shutting down immediately upon an oil pressure switch signal. Seems to me rush hour traffic bumper to bumper 75mph + in the middle lane is a bad time to loose power w/o warning.

I think you have a few seconds to react under minimal power and get to right and shut down then coast into emergency lane etc. Might not be a lot of time but something is better than nothing running along side and in front of tractor trailers.

The engine tolerates zero oil pressure at every oil change for ~ 5 +/- seconds right?

The cost of new bearings and some internal work is cheaper than buying a new truck or causing a wreck. It could be a bad oil pressure switch failure too.

Beedee
02-26-2007, 16:50
If you just used the swichgage for an alarm system with a buzzer or light. I'm not sure how to wire it into the system for a shutdown, but if you did want to have it shut down the engine then yes you would need an overide switch when starting. I was just thinking of having it as a seperate oil pressure gauge with an alarm rigged to it that would alert the driver when the oil pressure fell below a preset point, that way a person would have enough warning to get off the road before the pressure dropped all the way.
I would probably put the system on my own truck, but am thinking about selling it in the spring

DennisG01
02-27-2007, 13:59
OK, I don't have an update on the truck, yet. It'll still be a day or so until the shop can get to it.

But, I'm about 90% sure I'm going to use this: http://store.summitracing.com/partdetail.asp?autofilter=1&part=REB%2D140%2D1280&N=700+115&autoview=sku for the warning system - it's $17. After reading through all of your posts, I agree the buzzer would get annoying and trying to hook up to the "check gauges" light might be more complicated.

This system comes with a light that comes on under 15 psi (although if one wanted to, I'm sure a buzzer could be substituted, or used in addition) which I'll try to mount in my A-pillar gauge pod. This now seems to be the simplest system that'll do what I want. I talked to REBCO (the manufacturer) and they said the tee fitting is 1/8" NPT and is designed to fit the oil pressure sensor of Chevy small blocks. They weren't sure if it would fit the 6.5. Anybody know? I also have to admit that although I've heard the OPS talked about many times on this forum, I don't know where it is. When I get home, I'll see if my Chilton's book has it listed. My other thought is to use the extra "out" port on my remote filter mount, which I'll have to step down from 1/2" to 1/8".

moondoggie
03-01-2007, 12:23
Good Day!

Great topic. I always wanted a red light to come on when the "check gauges" light comes on in the dash. I wanted it bright enough so it can't go unnoticed. I wanted it to be bright enough that folks in adjoining counties could see it. I wanted it bright enough that the current it draws would stall the engine due to the alternator's being at max output. :eek:

Blessings!

a5150nut
03-01-2007, 19:52
Good Day!

Great topic. I always wanted a red light to come on when the "check gauges" light comes on in the dash. I wanted it bright enough so it can't go unnoticed. I wanted it to be bright enough that folks in adjoining counties could see it. I wanted it bright enough that the current it draws would stall the engine due to the alternator's being at max output. :eek:

Blessings!

Sounds more like the one in the rear view mirror !!!!!!!!!!!!! :(

HammerWerf
03-05-2007, 15:24
Dennis,

Another idea is a guage that combine not only the parameter, but also a warning/alert and an automatic shutdown.

DatCon has thaes features in their Smart Instruments series 2002 line.

http://www.datcon.com/products/4smart.htm

I've not used these. I am using a read only Water temperature guage on my 83CC. Works well and seems to be quite accurate for what I use it for.

HammerWerf