oil pressure and oil temp gage aftermarket

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As some of you guys know , from an earlier thread i posted, i had a low oil pressure switch failure.I replaced the switch yet i am not getting any warning most of the time at startup which leads me to beleive its a wiring fault. I want to install a real time oil pressure gauge and oil temp. I know where to out the sender for oil pressure, which basically a replacement of the low oil pressure warning switch. Where do i mount the oil temp sender ? There doesnt seem to be any threaded hole for it on the block. Engine is a 1986 mitsubishi 4g13, same as used in the mid 80s dodge colt.
 
Put in a street tee. Male end goes in block, two female ends for senders. No this is not an audition for porn
 
Thanks mitch. I have considered that but many people have said putting any kind of extension places undue strain on the block threads. I was actually wondering if anyone knows a secret or unknown place on this block that is plugged stock from the factory. Perhaps i could unplug that area and place the oil temp sender.
or is there a dual function sender & gage that you know of.
 
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There may be a number of sources of pressurized oil on your motor; you need to look at a diagram of the oiling system for your specific model.

Or you could buy a sandwitch adapter (goes between block and oil filter) which will have ports you can use (normally used for oil cooler lines).

Keep in mind that the pressure and temperature readings you will get are relative, not absolute. In other words a temp reading, for example, will vary depending on where the sender is located.
 
Thanks for the input guys.i decided to get just an oil pressure gauge and bought an aftermarket unit..supposedly from jasma japan. Anyway the oil pressure sensor thread end is 1/8 npt . I tried screwing the sender into the block and it went it just a little before it seized up. Looking at the oem switch, its probably 1/8 bsp..which is a british standard parallel thread. In order to get this to work, i ask my machinist to make a reducing bush/nipple combo so that i can screw it into the block..now the bad news is because of its similar size its impossible to get the sender end into the path of the oil flow directly like the oem switch. With the new adapter the sender end will be approx 10mm away from the block..so my questiona are:
1. Since the sender end is no longer as near as it should be to the direct oil flow, how will this affect the readings sent to the gauge. will it be on the lower side or higher side of the actual value ?
2. According to my service manual the oil pressure at idle at operating temp is 21psi. If i get a lower reading should i be worried ? I thought the rule of thumb was 10psi per 1000rpm...shouldnt it be 10psi at idle then..
 
Distance won't matter for pressure sender.

Oil pressure will vary depending on temperature, grade and how shagged the motor is. Read the manual for minimum pressure specs and as long as it meets those you are good to go. Don't worry about the 10psi/1000rpm stuff. It's not exactly a performance motor.

As for oil temperature, a cheap and easy way to do it would be to look at replacing the sump plug with a sender. It's Japanese, so it's probably got a metric plug and you might find a VDO sender with the right thread out of the box. I found a VDO water temp sender from a Rotax aircraft motor (M10x1) that fit my transmission drain plug perfectly. No modification required. You might get lucky.

Putting a temperature sender anywhere it's not actually exposed to fresh or flowing oil is a waste of time (like in a tee with your oil pressure sender. No flow, just dead-headed pressure). Years ago, VDO used to make a dispstick with a temperature sender in the tip also. Just another idea.
 
Thanks brad_c. Your information is great. I have done the wiring. Now i have a problem with the fitting to the block. After reading a few websites, i gather that placing a few extension fittings will place great stress on the fittings because of the vibration from the 4 cylinder engine. So one site recomended to use a flexible hydraulic hose and join to a tee..which means i could use the new pressure sender as well as the original switch that is wired to the dashboard. Now my question...this sender is supposed to be negative earth type. There is only one signal cable attached to it. Do i actually need to attach some kind of cable to conduct back to the block to bridge the gap of the non conducting hose ?
 
Yes, it will be negative earth so you will have to ground the sender. A quick and dodgy solution would be wrapping some copper wire around it and securing it with a worm drive hose clamp. When I did mine I replaced the original idiot light switch with a combined VDO sender/switch combo. So no tee or extension required, just needed to replace the connector on the existing switch wire with a crimp-on ring terminal.

There are some nice purpose built extensions on the market that are suitable. They are basically a huge aluminium hex bar that screws into the block, the existing sender screws into the end and there is a 1/8" npt hole in the site to screw a pressure gauge into. You'd have to seriously get some horror resonation to break that.

I had one of those for a couple of months, but the E-bay special pressure sender that came with the gauge could not cope with the oil temperature created while towing and it melted. No leak, but no work either.
 
I finally got the sandwich adapter and installed it. Found a leak at the sandwich adapter. Also the gauge was showing a maximum reading eventhough i havent started the engine..just turn to acc. I checked the grounding of the sender..and i surmised it was the teflon tape i used to seal the thread that was causing ground not to connect. I removed the sensor and screw in without the tape. This time the gauge worked and showed a reading of zero. I crank the engine up and it went to 5.4bar..78psi. As the engine warmed up..it went to 2 bar..29psi..i was happy..until i turned on the ac and the meter dropped to 0! Again i was dissapointed. So i checked the power connector with ignition turned to acc it showed 12v. I turned engine on it was 13.6v . I turned on the aircon..it dropped to 13.4v..which is very little. I dont understand why a drop of only 0.2v can cause the meter to read zero.
tommorow i will be going to a tuner shop to buy their gauge and sender set..i will return this [censored] ebay set. I think its faulty.
 
Before you toss it, check the voltage on the actual sender wire and see what changes when you turn the A/C on. Then do it again from the body of the sender to chassis. You may have a very bad engine earth and when you turn the A/C on you raise the voltage on the engine a couple of hundred millivolts.

Gauges and electricity are not rocket science. Measure and diagnose.
 
Originally Posted By: Brad_C
Before you toss it, check the voltage on the actual sender wire and see what changes when you turn the A/C on. Then do it again from the body of the sender to chassis. You may have a very bad engine earth and when you turn the A/C on you raise the voltage on the engine a couple of hundred millivolts.

Gauges and electricity are not rocket science. Measure and diagnose.

too late, i think the gauge is toast. I turned ignition to acc today, and it does the full sweep as usual, but with the engine still not started its not showing zero, but 2.5 bar.
I am actually pretty lousy at understanding electricity, especially reading diagrams and understanding the concept of earthing. It was my weakest subject in school besides chemistry. It is rocket science to me. I re read the manual last night, and i noticed it says that - is to be connected to the battery, i connected it to earth. I tried disconnecting from earth to - on the battery but the gauge is doing the same thing now at the position before start. I wonder if I connected it to - on the battery I wouldn't have faced these loading problems...
Anyway I will update you guys on whats going on with the pros later today.
 
I've used mechanical oil pressure and water temp gauges in many cars over many years. It will get you around your electrical issues, but you will need to properly route and insulate your lines for any cuts and abrasions-good luck.
 
I went with a professional installer, basically a racing garage. They had a better gauge and sensor in stock, a taiwanese brand NRG. The sender had 2 wires coming off it, and it uses a servomotor to run the gauge. after 3 hours of waiting, its done, and the i decided to get the oil temp done at one go since i will be payting less for labor since they are fixing one gauge. Since both are the same brand, i just had add the + and - to one set of cable from the car, and then link the oil temp meter, voila.
I am very happy with the performance of these. The oil temp gauge is very stable, the oil pressure gauge does glitch very little when the a/c kicks in, but always goes back to the right reading after one second. These are 10x better than the cheap one i bought from ebay.

this pic shows the old one wire sender..just wanted to show the sandwich adapter.

New gauges on the dash. They perform very well.
 
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