Inoperative Oil Pressure Gauge

[CC57]

All,

Need some troubleshooting advice please.

Sealed motor Thunder Roadster, approximately 20 races on the motor. Oil & filter changed after 2 race weekends.

Went to roll out for the feature last Saturday (after running 2 practice sessions) and the Oil pressure gauge read zero. Red light was on the panel. Normally, at idle, around 25#s indicated on the gauge.  Revved the motor a couple of times and the red light went out, but gauge still read zero.

Thoughts running though head: just checked and added ½ quart of oil. Oil was 2/3 of the way up sight gauge.

Did I not re-install oil plug: yes I did. What else? Gauge failed? Did the sending until wire fall off or break? Or what?

And ---Decision time. Should I risk it (blowing engine) or sit out race? Well, adrenalin and sitting 2nd in track points….. I went for it.

25 laps later: engine didn’t blow but gauge still at zero.

So my question is, how do you trouble shoot the oil pressure gauge, sending unit/sensor? Where are the components? Is the sensor the brass cylindrical unit mounted on the left-hand side of the oil pan? (and if so, no wonder we run low oil pressure reading trough turns, all the oil is thrown to the right side of the pan)  How do I identify the proper wire? Can I place a voltage source on the gauge and test its functionality?  etc, etc.   

While I'm at it: the Oil temp hasn't worked since I bought the (used) car. How does one go about troubleshooting it?

Thanks in advance all

[elimn8u_43]

I use mechanical gauges for both pressure and temperature. They are less likely to fail. I will see what I can dig up for information on the electrical gauges for you.

Geoff

[Tom Cole]

The round sensor on the bottom underside of the oil pan is the oil level indicator unit.

The oil pressure  line on mine is the silver plug with the copper tube coming out of it.

If I crank the engine and unplug that line, oil squirts out.  If it doesn't squirt out of yours, you have a big problem.  If it does squirt out, then it is something to do with your gauge.

[justfreaky]

 Try the tests on this page.
http://www.clarks-garage.com/shop-manual/elect-19.htm

 Sorry, only did a quick search, but thought it might give you some ideas.

 Steve

[qweedqwag]

If the guages are mounted in the dash find out what is behind them, wires or a little thin plastic tube (for the pressure guage) follow that to where ever it goes and make sure you don't have a kink in the tube type    whic h is mechanical pressure, it should go down on the right side of the engine, if thaere are no kinks most likely the guage is bad, if you drove 25 laps without pressure you would have made it about three and BOOM!!! If the red light stays on while reving the engine parked you have problems, those lights dont fail that often, check the guage first.

[CC57]

Would appear I have a defective sender.

I have electrical gauges. I grounded the sender to the frame, applied power to the starter (flipped the toggle swtch up) and the gauge pegged. Which my understanding is, if the gauge pegs, the sending unit is bad.

Anyone know where I can purchase a new sender? Yamaha shop perhaps?

Thanks all

[DARK AGE 53]

Yamaha shop perhaps?

That's where I'd start.

[elimn8u_43]

The sending unit is not a Yamaha part. Try your local 600 dealer or Autometer gauges.

Geoff

[CC57]

Autometer said it's not their component.

So it's a direct purchase from 600.  $30 fort theunit.  Seems high.

I guess if another one fails, I'll change out the gauge and add a steel briaded line and go to a pressure fed unit as opposed to the electric unit.

Thanks all for you replies.

[qweedqwag]

The only thing that scares me is if the pressure line ever lets go mmmm hot oil.


Mike

[JGRacing]

If you switch to a mechanical gauge, make sure to use the braded steel line and not the copper line.   I had the copper line break on a street stock and it sprayed oil right onto the headers.  Somehow it just smoked really bad and didn't catch fire.  If the braided line fails, it will only be a small leak and not anything dramatic. 

[CC57]

The only thing that scares me is if the pressure line ever lets go mmmm hot oil.
Mike

Granted, the electrical gauge is safer (possibly the reason 600 Racing put them in the cars?). But every racecar I've had before had a pressure line (tied into the block of the 350). Never experienced a problem, nor did I ever overhear of someone else experienceing a problem.

Now my fuel pressure guage, that's another story. I had the protective bladder(?) in the line to prevent the possibility of the line breaking and spraying fuel all over the cockpit.