8v71 oil and temp senders

[j.m.jackson]

What's your suggestions on electronic oil and temp sender locations on a GM 5303 with an 8v71 for accurate temps and pressures? I've got no gauges at all in the cockpit other than air pressure and volts, and don't feel great not knowing what's going on back there.

I did search the board before I asked that question. I know ya'll must have answered it somewhere, but didn't find it...

[TomC]

Wow-that's strange. My AMGeneral transit has an oil pressure gauge and water temp gauge (most important). Also has a high pitch signal and light when air pressure is low, oil pressure is low. Just a signal when water temp is too high, water level is low. I also have mechanical gauges in the engine compartment for oil pressure and water temp for comparison.
Easy to add gauges-typically there are spare ports or places to tie into the engine. My oil pressure gauge is at the end of the line-which means I only see sometimes 15-20psi when hot. Most oil pressure is taken at the oil pump.
To facilitate any additions to the engine, I bought 5-50ft 3wire extension cords of different colors that I cut so that the plug is in the engine compartment so I can simply unplug all if the engine needs removal. Bundled them together and ran them from the engine compartment under the bus up to the driver's compartment. Now I have 15 wires to use. I have added cruise control, and tachometer. Good Luck, TomC

[luvrbus]

90% of the Gm new look fishbowls I have seen didn't have gauges only the lights on the dash lol some had to be started from the rear only 

[j.m.jackson]

Starting is definitely interesting the with big dial over by the window... "off/day/nite/park".

Here's the current sensors / switches for water and oil:

[j.m.jackson]

I'm going to go with the electric VDO gauges for water and oil. They're very reasonably priced.

Also, the large air gauge doesn't work, and the PO replaced it with a smaller one where the oil pressure gauge should go and left the non-op gauge in place. Can anyone confirm that a 3 1/8th VDO gauge would work? I won't get to pull out the old non-op gauge until tonight.

[lostagain]

Why have gauges when hired drivers don't look at them anyway?

JC

[j.m.jackson]

JC,

And there is the basic truth! That's why there are idiot lights, buzzers, and automatic shutdowns installed.

So, the dash contains three 2-5/8th holes for volts/water temp/oil pressure, and a single 3-3/8ths hole for the air pressure gauge on the left. I think i'm just going to make an overlay so I can use the VDO 2-1/8th volt/water/oil gauges, and the 3-1/8th VDO air pressure gauge.

[Iceni John]

I reconfigured my dash so that the all-important coolant temperature gauge is now front and center.   I don't want to have it out of my direct sight, ever!   My dash now has its eleven gauges arranged so those in the center are the most critical, transitioning to the least critical at the extreme right and left.   I also eliminated all the original quarter-sweep gauges except for fuel level and voltage, replacing them with full-sweep Speedhut gauges instead  -  they're accurate,, easy to read, custom-made in USA with my choice of bezel/print/color/etc, and reasonably priced.

One bank of your engine may run slightly warmer than the other, so that's where your coolant temperature sender should be.   On my engine it's the left (passenger-side) bank that has the temperature switches and senders  -  according to my cheapo capillary backup gauges it's usually a few degrees hotter there than the other side.

John

[luvrbus]

The location of the temperature sender is right for a V drive engine both T stats are in that housing with only one sender that reads both heads ,you should install a oil sender on the engine as close to the oil pump on the front of the engine as possible not from that block where the manual gauge is now you will get a more accurate reading fwiw

[j.m.jackson]

Yes, I'm going to have to put a 3 gauge pod on top of the dash, the steering wheel center obscures all three of the stock gauge positions. I can't see the voltage gauge at all unless I lean forward. 

Where is a good location for the oil pressure sending unit? I do have the DD manuals for the 8V71, haven't spent quality time with them yet.  Also, there are three ports for water temp on the thermostat housing. Any idea which one is best?

[Oonrahnjay]

... there are three ports for water temp on the thermostat housing. Any idea which one is best? 

    I have no direct experience with a 8V71 but I'd pick a port before the thermostat, if one is available.  A stuck-closed thermostat can make your engine really hot at the same time your radiator and "top hose" (usually the hottest part of a cooling system) are cool.

[Geoff]

You should have an​ oil pressure gauge on a panel in the engine compartment.  It should be hooked up to a multi-port oil box that has several holes with plugs in them. Just use one of the plugged holes. The upper thermostat housing should have the original sending units and one or more plugs to add another sending unit to the housing.

-- Geoff

[j.m.jackson]

There is an open port to the rear of the bus below the existing temp switch, I think I'll use that. The one to the left in the photo above looks like it's outside the thermostats.

I saw the ports in the block up on the firewall, but i've seen where people have seen low pressure up there. anyone have suggestions on an available port close to the oil pump?

[Geoff]

There is an oil galley that runs across the middle side of the block.  The one at the rear is probably already being used, so if you look at the front side you should find a 1/8 or 1/4" plug that goes to the oil galley.  If you find the rear one, the front one will be in a straight line to the front.  It is very close to the oil pump.  The only problem you might encounter is getting the plug out.  It is usually in there pretty tight as it was installed at the factory, and they always put plugs in too tight.  You may have to heat the area around the plug.  If you can't get that one out, there is another plug at the front of the engine in the same straight line.  Did you look at the engine compartment oil gauge?  Where it hooks up is the easiest place to put a sender.

--Geoff

[j.m.jackson]

Geoff,

Here's three plugs in the rear facing head on the 'back' of the engine. I believe the lower one is water (it has a draincock on the drivers side, the large plug is also for water (water outlet on driver side) and the upper one is oil. Maybe?