Oil Pressure guage

My oil pressure guage pegs itself as soon as I start the boat and stays that way untill I turn it off. I am guessing that the sensor. Can someone tell me where the sensor is and how hard it is to replace.

Thanks in advance
Jon

Jimbo ...good advise! Tape may cause a bad connection...you don't need it there anyway....however if you use T Tape.on any sender(oil sender may need it)...only wrap the top theads so you get some metal on metal!

And yes...oil pres. gauge should be marine not auto...they will not read the same!

My water temp gauge has been wrong ever since I replaced the sender. I did use teflon tape. Is that possibly the problem. I used a laser temp thing and the block temps and such are correct. Are you saying that on sensors such as the water temperature, you can just screw them into the intake manifold without anything on the threads? Would something like yellow thread sealer (liquid snot) work or would that screw up the connection too?

Thanks for your info!

I recently replaced my temp sender and the instuctions explicitly said not to use any teflon tape or other sealer. The sender is NPT, pipe thread, which I believe is tapered. So far, so good - no leaks and the gauge is accurate.

I too am having problems on my 77 302 temp gauge. Does anyone know what the resistence values at certain temps are? I'd like to go after it with the ohm meter and see if it is the sender or gauge. Thanks, Pete

I have a different problem I replaced the oil sending unit with the one from skidim and my pressure doesn't move it's always around 20psi no matter what the rpm. Did I get a bad unit? do I have a bad gauge? or is there a much bigger problem? It does start a zero when off or ignigtion button and key are on but as soon as you start it moves to around 20psi. 351w '86 martinique

Hi Martinque ( Andy )

Sounds like you have been given the wrong sender unit.

Firstly
You can check the gauge to see if it will go to full deflection (i.e highest reading ) by grounding the sender wire to the block as 79 says.
Only ground it long enough to see if it goes to full deflection, grounding the sender wire is not quite the same resistance presented as at the very highest oil pressure and can damage you gauge if you do it for long periods or time.

Secondly
Gauges and sender units are a matched pair from their manufacturer. Meaning for a gauge to read correctly the sender unit must change to specific resistances over a range of pressures.

If the sender unit is not correct for the gauge it will not present the correct resistance for the range of the gauge.

In your case it sounds like the sender is not matched to the gauge.

Regards
Rob

what's the coil have to do with oil pressure????????

he is just trying to rattle your chain 79,sounds like he found it.....boatdr

I have had a pegged oil pressure gauge for a while. I have seen it come down to a proper level while the engine but most of the time it is pegged. I ordered a new sending unit from Ski Dim and replaced it Saturday. I did use teflon tape and nothing has changed. First thing I will do is remove the t-tape and try again. After reading this thread it seems to me there must be a short somewhere because if I were to remove the wire and touch to the block it would do the same thing it's doing now. And now the wire may be insulated from the block because of the t-tape. Everything is original from the factory till I changed the sending unit. Could the gauge be bad if its pegged 90% of the time? I'm don't think the wiring has changed between the gauge and sending unit. I did change the steering cable a couple years ago...maybe I hit something under the dash?
Thanks for any help.

Pete, there were no instructions in the box. I should be back at the boat this weekend and will check reading from the gauge power side to ground. Will this tell me if the gauge is good?

I failed to let you know I have a 93 Ski Nautique. I will try and get a couple pictures to post on a diarie entry.
Thanks

Jim, if you determine the gauge is faulty and need to replace it, Summit Racing has one that is very similar. I might also be interested in your old one.