WTF No Oil Pressure?????
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 1,154
Likes: 1
From: St Augustine FL
WTF No Oil Pressure?????
Well, I thought I was having fuel pressure problems still may have fuel pressure problems. I drove the car last night and I noticed the oil pressure gauge read 0. I just replaced the sending unit 2 months ago. Bad sending unit?...Bad oil pump? I can smell gas in the oil. The car Drives fine under normal driving conditions. No power and is spongy under heavy or full throttle. The engine does rev under heavy throttle but no power. No knocking noise. I did start to smell a mild burning smell for a few seconds. What in the heck is going on with my car? I fix onething then 2 more thing s go bad or break. I am so frustrated that I can't see straight. Someone please help.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
pull fuel pump and check it out, its a good candidate for the gas in the oil thing. Gas may have thinned out the oil and be giving you a very low oil pressure, change the oil. Get a mechanical oil pressure guage to check oil pressure with. More work, but you can pull the dist and run the oil pump with a good heavy duty drill, see if the pressure comes up.
Get the fuel and oil situations stable, then tackle the performance issues.
Let us know
Dan
Get the fuel and oil situations stable, then tackle the performance issues.
Let us know
Dan
Instructor
Joined: Apr 2006
Posts: 180
Likes: 0
From: Jersey
I'd have to go check the manual to confirm, but I don't think your car will run unless oil pressure is present. I think there is an interlock to the ECM - no oil pressure - no fuel pump on. Also, the sending unit for the ECM is different then for the gage. So you may just have a gage problem. Also, if you had no oil pressure, the motor wouldn't live very long.
I saw your other post looking for a pump. I would do a lot more trouble shooting before dropping the pan. Theres a whole bunch of easier things you can do to see whether oil pressure is present or not. Highly unlikely the oil pump is failed. And if you do need a pump, get a brand new one. They're cheap relatively speaking.
If you changed the sending unit then maybe the gage is shot. Put a meter on the sending unit leads and see if you get voltage with the engine running (briefly). Don't know what the spec is on voltage vs. pressure. Somebody here will know. If you still can't confirm pressure, pull the sending unit and temporarily hook up a mechanical gage. One with an oil feed tube directly to the back of the gage.
I saw your other post looking for a pump. I would do a lot more trouble shooting before dropping the pan. Theres a whole bunch of easier things you can do to see whether oil pressure is present or not. Highly unlikely the oil pump is failed. And if you do need a pump, get a brand new one. They're cheap relatively speaking.
If you changed the sending unit then maybe the gage is shot. Put a meter on the sending unit leads and see if you get voltage with the engine running (briefly). Don't know what the spec is on voltage vs. pressure. Somebody here will know. If you still can't confirm pressure, pull the sending unit and temporarily hook up a mechanical gage. One with an oil feed tube directly to the back of the gage.
Instructor
Joined: Apr 2006
Posts: 180
Likes: 0
From: Jersey
And if you really don't want to run the engine, you could pull the distributor, pull the valve covers, get a drill primer and crank the oil pump. If the oil pumps up to the top of the heads, your oil pump is probably OK.
Race Director
Joined: Jul 2004
Posts: 12,703
Likes: 329
From: Scottsdale Arizona
Originally Posted by Black 82
I'd have to go check the manual to confirm, but I don't think your car will run unless oil pressure is present. I think there is an interlock to the ECM - no oil pressure - no fuel pump on. Also, the sending unit for the ECM is different then for the gage. So you may just have a gage problem. Also, if you had no oil pressure, the motor wouldn't live very long.
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I think your best be is to start by looking at the wire from the sender. If you recently worked on it, perhaps it's nothing more than the connector having come off or the wire having been rerouted past an exhaust manifold and having burned through.
Race Director
Joined: Dec 1999
Posts: 16,945
Likes: 9
yes, the oil pressure sender next to the distributor is also a switch, the 12V feed for the fuse pump goes through it when there is oil pressure. The fuel pump relay only primes the system and runs the pump when starting, when the engine is running the relay disengages and the pump gets the 12v from the switch/sender so if your engine is not stalling due to no fuel you definitely have oil pressure
IS your gauge working properly? Check the sender/switch. Remove the alrge conenctor (rubber socket) and check if it's all clean in there.
It could be that the sender is shot, meaning the pressure switch for the 12V to the fuel pump works but the variable resistor part for the gauge does not. If you ground the lead for the gauge the gauge should peg to full. There are 3 prongs inside, the 2 blue wires (I think both are blue, could be one is tan/white) are for the fuyel pump, the other one is for the gauges. If you don't know which one to ground check w/ a multimeter, one of them has 12V on it (ign. switched) and is for the fuel pump, one of the 2 others is for the gauge. I don't remember exactly which one you need
IS your gauge working properly? Check the sender/switch. Remove the alrge conenctor (rubber socket) and check if it's all clean in there.
It could be that the sender is shot, meaning the pressure switch for the 12V to the fuel pump works but the variable resistor part for the gauge does not. If you ground the lead for the gauge the gauge should peg to full. There are 3 prongs inside, the 2 blue wires (I think both are blue, could be one is tan/white) are for the fuyel pump, the other one is for the gauges. If you don't know which one to ground check w/ a multimeter, one of them has 12V on it (ign. switched) and is for the fuel pump, one of the 2 others is for the gauge. I don't remember exactly which one you need
Last edited by Twin_Turbo; May 25, 2006 at 01:40 PM.
