replacing the oil pressure sending unit

[grumpyvette]

viewtopic.php?f=38&t=446&p=550&hilit=+pressure+sensor#p550

this socket helps
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viewtopic.php?f=80&t=728

viewtopic.php?f=32&t=162

the oil pressure sending unit on most gen I and -gen II chevy engines is located near the upper rear engine where the distributor is located on the first gen engines.

theres lots of guys that spend days trying to stop leaks the the threads or connection plumbing on those sensors all to no gain, simply because its RARELY the threads that leak, its commonly the sending unit itself that defective and leaking internally,or externally, swap it out and when you install the new version coat the threads lightly with high temp silicone




read thru these links
viewtopic.php?f=54&t=3536

viewtopic.php?f=54&t=2187

viewtopic.php?f=54&t=117

viewtopic.php?f=54&t=3834

viewtopic.php?f=54&t=296



pressure is the MEASURE of resistance to FLOW, ID suggest checking the pressure with a different gauge BEFORE going any further as thats most likely a defective gauge or sensor
the oil temp sensor is located in the main oil feed from the filter in the block,

Id be looking to replace the sensor, if your having odd pressure readings as they go defective frequently,then theres also the connecting wire or gauge, oil temps especially if the engine maintains fairly consistent oil pressure and flow rates, the oil pressure sensors up near the distributor. Id suggest verifying the oil level and pressure, it should be about 205F-225F at operational temps at idle and pressure should be no lower than 10 psi per 1000rpm, or higher than about 30 psi at idle with a 10w 30 or 10-w 40 oil, the bye pass should limit pressure to about 65psi, its more than likely a defective sensor or gauge

viewtopic.php?f=80&t=728&p=9217&hilit=temp.sensor#p9217

 

[grumpyvette]

any time your having a oil pressure problem think about this

step one ,verify the gauge and sending unit are accurate and your having a oil pressure problem using a different test gauge,

now this might not be the cause in your case but its VERY common for guys to swap in a new high volume oil pump and not realize that high volume means the pump gears are longer and that requires a longer /deeper oil pump body that places the oil pump pick-up closer to the oil pan floor, if they did that (ESPECIALLY with out checking clearances or brazing the oil pump pick-up to maintain a 3/8"-`1/2" clearance with the oil pan floor) the oil flow into the pump gets restricted. at idle pressure fine, but as soon as the rpms build the restriction limits oil flow into the pump and pressure drops off, adding a qt of extra oil changes nothing, this is the source of the MYTH that high volume oil pumps pump the oil pan dry, but in truth there's plenty of oil its just not allowed to flow into the pump due too clearance issues, the cure is brazing the oil pump pick-up for the necessary 1/2" oil pan floor clearance AFTER carefully measuring , with modeling clay, to make sure its maintained with the oil pan in place, many guys braze a spare 3/8 NC nut to the edge of the oil pump pick-up so it CAN,T get closer than 1/2" from the oil pan floor

if you have a constant oil leak from the upper rear engine near the distributor area,its a safe bet its the oil pressure sensor, or fuel pump switch or the connections to the block,or the intake rear seal, replace the sensors, if that does not cure it the intake gasket most likely needs to be replaced.

http://www.ecklers.com/search.asp?action=freeSearch&free_text=oil pressure sensor&yearConstraint=1985&searchHistory=

the oil pressure switch might be defective, if the fuel pump won,t run, even if its new
and at $11-$35 Id just swap it out if your concerned

http://www.ecklers.com/product.asp?pf_i ... ept_id=153

http://www.ecklers.com/product.asp?pf_i ... ept_id=153

theres a good deal of good and useful advise, in this thread but Id point out the
sensor(s) next to the distributor, base ,could be a cause of a problem, because occasionally one of these starts acting up intermittently causing the fuel pump or ECM to stop working,or the VATS system, or the FUEL SUPPLY SYSTEM.

if you hear the fuel pump pressurize the fuel rails but the engine only starts than stalls, or fails to start, its frequently the fault of a defective oil pressure sensor



low oil pressure or a defective oil pressure sensor will cut off your ignition

both these sensors, located near the base of the distributor on the block, are known to fail & leak,oil at times, especially the smaller one with two blade connectors
the single terminal sensor runs the oil gauge the dual connector runs the fuel pump ONCE theres about 5 psi of oil pressure but they do fail and they do leak oil when they fail and both are commonly located near the distributor


http://www.digitalcorvettes.com/forums/showthread.php?t=89593

http://forum.grumpysperformance.com/viewtopic.php?f=32&t=36

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