JJs84Berlinetta

Hey guys ok I had a oil pressuer gauge that was reading way above 80 so changed out the pressure switch today. Now oil is reading low like 5-10 when idleing then like 30 on the road. The oil lights keeps coming on at idle the goes as i drive. Oh i do have a leak somewhere just hoping not to confirm what im thinking and that is a bad beariing clearance which means a new engine. Help please thank you

camaronewbie

Did you check the oil level? Might just be another bad sender. Or you got the wrong one from the parts store.

There are 3 different types for these cars, a two wire, and a 3 wire. Three wire cars just had the one unit, located above oil filter (I think this is 1990-1992). Other cars had a one wire unit on the china wall driver side of distributor, and a two-wire unit above oil filter (one-wire unit feeds gauge, two wire unit feeds fuel pump).

Then, to top it all off, there is a one-wire for gauges that is different than the one-wire for idiot lights.

JJs84Berlinetta

Well the unit i replaced today was at the filter and it had one wire going to it.

camaronewbie

Oh - 1984 carbed car - no 2-wire oil pressure switch for that, since there is no electric fuel pump

So double check part number and make sure they got you the right one for the gauge rather than for the idiot light.

Otherwise, might just be a bad "new" part, or maybe you have a gauge issue - these cars gauges aren't really for diagnosis as much as they are for 'sporty looks'.

JJs84Berlinetta

Well i checked the oil level it is good, I also hooked up a mechanical guage which read 35-40 psi at idle. So i hooked the oil pressure switch back up and it read 40 psi at idel. I go to drive the car this morning pressure bottoms out to around 5-10 psi, then goes up to around 20-25 when i am driving then drops back down to 5-10. I drove it to work today becuase i had to had no problems other than the light coming on and the guage reading low. Do you think it might just be a bad wire or switch.

camaronewbie

Sounds like bad wire, bad sender, or bad guage.

Oil pressure changes with heat and rpm's. Heat makes oil thinner, thus less pressure - that's why 1st thing the car has more oil pressure, and when it warms pressure drops.

Engine RPM affects pressure since it's getting pumped faster making more pressure.

The fact that you gauge moves when rpm's increase is good - tells you oil is moving, and is moving faster at higher rpms (what you want). And since you checked oil and it's full then you are golden, just not seeing golden numbers.

Try changing sender first, if that doesn't help, then test resistance on the wire from sender to gauge - if you have any resistance then maybe its a wire issue and it needs fixed/replaced. If all that fails, then snag a new (used) gauge off ebay/TGO classifieds/Thirdgen Ranch/Hawks Thirdgen/etc. and swap out - might still get another 'not perfect' gauge, but won't cost much to try.

But in the end, as long as you have oil, and you can tell it's moving, then no worries.

JJs84Berlinetta

Thanks Camaronewbie think i am jsut going to install mechanical guages in the car i bought Sunpro "Iknow crappy but cheap for now" I know I have to hook up the oil pressure to the oil pressure switch port but do you know wher eto hook up the temerutur wire at for a 84 camaro

camaronewbie

Temp sender driver side head between #1 and #3 spark plugs - should have a dark green wire to it from factory gauge.

JJs84Berlinetta

Do i have to rewire it somehow or can i just go straight mechinical guage

camaronewbie

Depends on the gauge manufacturer I guess. It should have instructions.

GTAwheelman

you can go straight to the mechanical. it does not use any electrical for the temp reading. the only electrical wires you have to hook up are for the gauge light and ground. it will work without having those wires hooked up. so will your oil gauge.

you are in for a treat when trying to remove that sender on the china wall. its almost impossible to get too.

JJs84Berlinetta

NEWBE-What is the "ChinaWall"

ASE doc

Since your gauge sending unit is above the filter, you dont need to worry about the china wall, unless you have a leak there. The china wall refers to the rear intake manifold end seal.

JJs84Berlinetta

Ok, so hooked up the SUNPRO TRIPLE GUAGES guage is still reading 5-10 at idle and goes to 40 right around 1600 rpm's. Not realy sure i trust that plastic line to the oil pressure barley tug on it by accident and it came right out. Going to get the copper line for it tommarow.

ASE doc

I recommend using steel brake line for that. The copper will get brittle after some time and can crack. Be sure to cut the line extra long and bend a coil into it for flexability. I use a large socket and wrap the line around it a few times to create the coil. This coil will take the flexation of engine movement and help prevent fatigue in the steel tubing. What weight of oil are you running? If you have a high mileage engine(100K+) you may need to step up to 10-40 to maintain oil pressure at operating temp.