Bob Boyer

Okay, so I'm checking out the posts regarding adding a second (working) oil pressure gauge so the actual oil pressure can be tracked whilst driving. What I'm curious about and didn't see mentioned in any threads was whether anyone has merely replaced the sending switch with an actual oil pressure sending unit that sends a signal to the original gauge in the stock cluster. We used this trick with great regularity over in the Miata world and though the needle would read on the low side, it did swing with the pressure so you either got used to it (my strategy) or you were really **** and repositioned the needle so it showed full pressure when the needle was straight up.

Either way, we had working oil pressure gauges. Is this strategy possible (I noticed a reference to throwing codes if the stock switch wasn't plugged into the computer...) on the V8 Mustangs?

Many thanks.

danzcool

The problem is the programming in the gauge cluster. I believe the oil pressure unit sends an actual pressure and it is available over the can-bus, one fairly easy option is to use the aeroforce interceptor scan gauge that allows you to read all the info available to the ecu. This includes things such as coolant temp (actually head temp), cat temps, fuel pressure, oil pressure, and a whole lot of other things.

Bob Boyer

I see. Scan gauge is probably my direction in this case. Didn't realize the cluster itself read into the computer - that's the difference 5 years makes.

danzcool

I don't see oil pressure listed in the scangauges list of parameters available, so you may need to look at some other option for oil pressure:
http://www.aeroforcetech.com/products_interceptor.html

It's possible the oil pressure sensor is a dumb on or off. I know that the coolant temp acts in the way I described, the temperature is known, but the cluster presents it as one of 3 or 4 states cold, (maybe warm), normal, and hot, and when the threshold is passed from say cold to normal it is programmed to give a slow sweep between the cold and normal.

moosestang

The aeroforce gauge doesn't have an oil pressure option, but you can use it to display oil pressure with an after market sending unit.

I wanted to do an oil pressure gauge, but T'ing into the stock placement is such a PITA and I don't feel comfortable with the sandwich adapters for the oil filter..

Bob Boyer

Yeah, the sending unit on the Miata was kind of in a painful location as well. I may give this a go, however, and let everyone know if it works. VDO makes several sending units for different pressure ranges; I'm thinking if I can find out the proper pressure range for my car, I can just screw in a real sending unit instead of what I think is a switch, based on the behavior or the meter.

They used to be about $30, can't have gone up much. Or I could be really surprised.

BTW, Moosestang, I kinda like the road in your Buell pix. It looks kinda familiar.

moosestang

I'm sure you're familiar with it. My folks live in Franklin, NC, so I visit it as often as my wife will stand.

I doubt the ecm will be able to interpret the signal from an aftermarket sending unit, but you can try or just unplug it and live with the engine light on. Maybe you can plug it in and just let it hang there. It will read atmospheric pressure and not set a code! lol!

I recommend the aeroforce gauges to everyone. It's so useful as a diagnostic tool. I have mine hooked to an lc1 wideband sensor. I usually have that displayed along with fuel trims or fuel pressure. It's worth it just to see the head temps.