No Oil Pressure
Thread Starter
Racer
Joined: Nov 2005
Posts: 340
Likes: 0
From: Dublin
No Oil Pressure
Hi
I've got zero oil pressure, changed the sender and still reading zero ohm's.
Whats the next thing that I should do?
The car hasnt been driven for the past few years.
Thinking to replace the oil pump, anything else I should do before this?
I've got zero oil pressure, changed the sender and still reading zero ohm's.
Whats the next thing that I should do?
The car hasnt been driven for the past few years.
Thinking to replace the oil pump, anything else I should do before this?
Melting Slicks
Joined: Aug 2010
Posts: 2,207
Likes: 26
From: Ocean County NJ
Im not a mechanic, so take this message of personal experience from a driver with a little mercy. I had a similar low pressure reading and found the culprit to be the oil pressure line. The copper or brass nerled coupler was lose and the line was disconnected. Everything performance-wise was functioning properly, except for the oil pressure gauge line between the engine and gauge. Hope your solution is as simple as mine was!
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
But your car shouldn't have a sender. If it does, someone has replaced the mechanical guage with an electric guage. Does it have corvette or aftermarket guages?
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Thread Starter
Racer
Joined: Nov 2005
Posts: 340
Likes: 0
From: Dublin
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
Thread Starter
Racer
Joined: Nov 2005
Posts: 340
Likes: 0
From: Dublin
Is there any difference in the way you test the ohm output on the temp sender than the oil sender?
Thought by changing over to the electric gauge you remove the risk of an oil leak inside the car!
Pro
Joined: Apr 2002
Posts: 538
Likes: 0
From: Astoria OR
One way to test the gauge itself is to ground the wire going to the sensor which I think should make the gauge read to it's max. With it open, it should read to it's minimum.
That being said, if it were me, I want to be sure I did have oil pressure. To do this, try a mechanical gauge with a short piece of trubing. The new ones even have a plastic tubing.
Make sense?
That being said, if it were me, I want to be sure I did have oil pressure. To do this, try a mechanical gauge with a short piece of trubing. The new ones even have a plastic tubing.
Make sense?
Drifting
Joined: Jun 2010
Posts: 1,781
Likes: 15
From: Oxford Ohio
Use copper tube and properly install and you shouldn't have a leak. I've never gotten a bad reading from a mechanical gage. Only issue I've ever had was with an electric gage. I'd use the mechanical to verify an electrical.
If you got an ohm read, how would you know what that reading related to, as psi.
If you got an ohm read, how would you know what that reading related to, as psi.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If you have an electric oil pressure gauge, the possible reasons for having a "no oil pressure" reading are:
1) engine has no oil pressure (unlikely if it is running OK and not noisy...but be careful, just in case);
2) bad sending unit (since you've changed it, that is not likely to be the problem);
3a) bad gauge....If you can access the back of the gauge (if not in the stock gauge cluster), it should have 12v going to it and a 'signal' wire from the sender. With the ignition on, use a voltmeter to see if 12v is present at one of the connections on the back of the gauge. If not, your gauge is not getting power to it and it won't function. Find/fix the reason for not getting power to the gauge.
3b) To check the function of the gauge, disconnect the sender wire from the gauge; with voltage going to the gauge and no sender wire connected, the gauge should read "O" psi (full scale to the left). Now, connect a 'dummy' wire to that sender contact and run that wire to a known-good ground point. The gauge should read full scale to the right. If those two checks are OK, the gauge is OK.
4) bad wiring...If check #3b went as expected, then your sender wire has a break in it somewhere. Check it and/or replace it.
Good luck.
1) engine has no oil pressure (unlikely if it is running OK and not noisy...but be careful, just in case);
2) bad sending unit (since you've changed it, that is not likely to be the problem);
3a) bad gauge....If you can access the back of the gauge (if not in the stock gauge cluster), it should have 12v going to it and a 'signal' wire from the sender. With the ignition on, use a voltmeter to see if 12v is present at one of the connections on the back of the gauge. If not, your gauge is not getting power to it and it won't function. Find/fix the reason for not getting power to the gauge.
3b) To check the function of the gauge, disconnect the sender wire from the gauge; with voltage going to the gauge and no sender wire connected, the gauge should read "O" psi (full scale to the left). Now, connect a 'dummy' wire to that sender contact and run that wire to a known-good ground point. The gauge should read full scale to the right. If those two checks are OK, the gauge is OK.
4) bad wiring...If check #3b went as expected, then your sender wire has a break in it somewhere. Check it and/or replace it.
Good luck.
Melting Slicks
Joined: Sep 2004
Posts: 3,227
Likes: 670
From: Northeast
I use a oil pressure switch for my electric choke. The only way a current will head there is if I have oil pressure, meaning the car is running. In this way I can work in the engine compartment, with the key on, and not have a current on the choke.
Last edited by BKarol; Feb 10, 2011 at 01:14 PM.
Terrorizing Orange Cones
Joined: Oct 2007
Posts: 2,572
Likes: 17
From: Northern CO
I believe you can perform a mechanical check of the oil pump function without the engine running. That will determine the operation of the oil pump without dropping the oil pan.
You'd need:
* instructions for distr remove/replace
* spare distr drive shaft or purpose built oil-pump tool
* electric drill
* replacement valve cover gasket(s), distr gasket
It would involve removing the dist and a single valve cover.
Using the electric drill with attached oil-pump tool, insert shaft into distr bore, engage top of oil pump driveshaft, spin the shaft and note oil delivery from pushrod end at contact with valve's rocker arm.
You should feel the drill lug down as pressure builds. Depending on size and torque rating of drill, be careful not to burn up drill.
That'll determine whether oil pump is failed or ok. Then follow other recommendations here for the gauges, lines, etc.
You'd need:
* instructions for distr remove/replace
* spare distr drive shaft or purpose built oil-pump tool
* electric drill
* replacement valve cover gasket(s), distr gasket
It would involve removing the dist and a single valve cover.
Using the electric drill with attached oil-pump tool, insert shaft into distr bore, engage top of oil pump driveshaft, spin the shaft and note oil delivery from pushrod end at contact with valve's rocker arm.
You should feel the drill lug down as pressure builds. Depending on size and torque rating of drill, be careful not to burn up drill.
That'll determine whether oil pump is failed or ok. Then follow other recommendations here for the gauges, lines, etc.