New Gauges?

[former4banger]

So I just got a 1994 Mustang 3.8l v6 with a 5 apeed. The temp and oil gauge read extremly high, pretty much in the read and the fuel gauge is not working. Always reads empty. The temp gauge reads hot after I drive for a while. The cars not over heating, there is no white smoke from the tail pipe.now foam or anything in the oil so I don't thing I blew a head gasket. I drove it home after buying it from Washington to Oregon (about an hour and a half) it read hot but wasn't over heating. I changed the coolant temp sensor and the temperature switch but still reads hot. Any ideas?
What would you suggest about the oil pressure? it's always reading in the red.
And the fuel gauge always at empty. I need some help

 

[former4banger]

Oh I forgot to mention, the previous owner changed the water pump.

 

[former4banger]

Anyone????

 

[jozsefsz]

Potential wiring problems are very hard to diagnose in person, much less to guess at online. In general I'd suggest you get a multimeter and a good manual and check resistances and voltages for the gauge circuits in question. Check all of your engine and body grounds for corrosion. Check any pertinent fuses and the general condition of your wiring (nothing like an old car with a hacked in stereo and remote start system to mess things up!). If you suspect your gauge cluster (it's possible), consider picking up one at a scrap-yard and swap it in to see if you get the same results.

I had an old 3.8 years ago. It eventually had a bad head-gasket, and I made the mistake of trying block-sealer before breaking down and fixing it properly. This thoroughly clogged my radiator, so I always, and legitimately, ran hot. That may be somewhere in your car's distant past too -- or perhaps a bunch of radiator sealing 'quick fix' by the previous owner before changing a leaking water pump. Start with making sure all the air is out of your cooling system, and see if running the heat on full-blast brings down the temp at all. If so, I'd start to suspect a clogged radiator.

The oil pressure is just an on / off gauge. Check wiring to the pressure sender, replace sender if necessary.

The fuel gauge could also be a bad sending unit or wiring. You can jump the sender wires (at the rear of the gas tank) to see if you can get the gauge to move.

Good luck.

 

[former4banger]

I will check the sending unit for fuel and the pressure sender for oil. The previous owner did swap in a new radiator and all hoses.
When I drive the car, there is a slight chirping sound. It sounds like it's coming from the water pump.
I will try the heater trick and see what it does. I'll snap a photo of the water pump and put it on here. It looks like it was installed kind off half assed.
With it not showing any symptoms of a blown headgasket besides the running hot, is there any other way to check to make sure?

 

[Chythar]

There are two temperature sensors on both the V6 and V8 Mustang engines; one that feeds the computer, and one that feeds the gauge. The one that feeds the gauge may be bad. Follow the upper radiator hose back to the engine, then look to the right of it; there should be a small sensor screwed into the intake manifold with a single wire pushed on to the top. That's the CTS, the coolant Temperature Sensor, the one that feeds the gauge in the dash. It may be bad.

The ECT, Engine Coolant Temperature sensor, is to the left of the upper radiator hose. It's screwed into a metal coolant pipe; the pipe leads to the back of the engine. That sensor tells the computer how hot the coolant is. If that sensor is bad, your gas mileage will be really bad and you may actually overheat the engine if you push it too hard.

If you buy a code reader that can read PIDs (usually the pricier ones), you can see what the computer sees for a number of sensors; including the ECT output. That's the only I know of to tell which sensor is bad.