RPM, Oil Pressure, Water Temp guages

Big Hammer · Apr 25, 2012

My Mitsubishi Buck has no guages. I want to know what is going on with oil pressure, water temp, and RPM. Seems it should be fairly simple to add the guages... anybody done that? What did you use?

Thanks

Mark

evan price · Apr 26, 2012

My Buck has a tach.
Since a Diesel has no ignition system, to drive the tach you need a cable driven tachometer. The Mitsu engine has a drive for the tach already. You just need the cable and the guage itself.

As far as the other guages go, any automotive type guage will work. I prefer the electric models over the mechanical ones because with mechanical guages if you damage the 1/8" oil pressure tube it leaks, and the temp guages you have to route the big thick thermocouple tube to the dash.
An electric guage you just need to run a thin wire for each guage.

Big Hammer · Apr 26, 2012

So I already have a drive for the cable...? where does it hook up? Can I find a cable and tach locally?

I assumed that automotive guages might work. Thanks

Botetourt · Apr 27, 2012

on the exhaust manifold side of the block, look straight down between the first two exhaust ports.

the cable screws in vertically. I have no idea about getting one, except from one of the vendors frequently mentioned on here, like Valley Power. I deal with them cause their local for me, but it seems like the others are good too. They have used parts, new parts, and some fabricated parts for items no longer available.

Ilikeurtractor · Apr 28, 2012

You can also install the diesel version of "Tinytach". Search for it on the web if you're interested. It's electronic and connects to an injector line so it makes installation pretty easy and it pretty neat technology IMHO. Be aware though, it doesn't work in temperatures less than around 30 deg. F so it is somewhat limited (and they don't mention this on the site or in any of their documentation and seem to ignore requests to acknowlege this limitation and address it). I don't considered it cheap either at about $100 currently.

Botetourt · Apr 30, 2012

Evan, I read in an old post that the Beaver sending unit is 3/8 NPT. Is that true for the Buck, too? Glanced at some Sunpro gauges at Advance just now, they've got a couple of adapters in the package, but I didn't have the sending unit with me to compare. I haven't had an overheating problem, but I have tested my sensor, and it doesn't work. Mitsu wants like $160. I'm going to start mowing with mine, so I might want to keep an eye on the water temp.

oliver28472 · May 1, 2012

The oil pressure port for the sending unit for the idiot light is not npt. It is 1/8" BSP. I bought an adapter at O'Reilly's for about $10.00 to adapt it to 1/8" npt. Some of the other stuff though is npt. The part number for the adapter is an Eddleman 265220 at O'Reilly's.

Botetourt · May 1, 2012

I pulled the water temp sending unit out and matched it up at the hardware store. It is indeed 3/8 NPT. While I had it out, I decided to test it again, this time in the oven instead of a pot of boiling water (duh, realized it's under pressure from the 10 lb radiator cap and boiling point is higher). Not really scientific because air won't transfer heat like water, but it worked after warming up in a 250 degree oven. I'll postpone the gauge unless I have a problem. BTW, the drain plug above the oil filter is 1/4 NPT, that's probably not a bad spot to put a sending unit if you want to keep your idiot light, unless you're going to be draining your cooling system frequently.

Ilikeurtractor · May 1, 2012

You can use cooking/motor oil to test when your switch operates since it won't boil like water. Get a candy thermometer, put some oil in a pan on your stove, hook a multimeter to the switch set for testing continuity, and see what temp the thermometer is at when the meter indicates a closed circuit. I wouldn't test above 300 deg F though to minimize fire hazards (ie if your switch is not closing by 300 deg F replace it - most switches I've seen close by 230 deg. F).

Ideally the temp switch would be in the cylinder head as that is where the highest temps will show up first. Having one somewhere though as a backup would certainly be better than none though.