Sudden Loss of Oil Pressure, then Perfect....

[needforspeed440]

Ok guys, here is what happened. Last night I was driving the stang enjoying the weather. I was on the phone and all of the sudden heard a bit of knocking. Not real loud, but it didn;t sound good. Well I looked down and the oil pressure gauage showed nothing (stock gauge). I pulled over and got out to check the oil. It had all the oil, and as far as I could see the wire was still on teh sending unit. Well after looking I got back in and started it up. Pressure was perfect and I couldn't hear a tick. WHATS UP!!??? Should I be nervous? In the process of getting a more reliable gauge.

THanks

 

[QDRHRSE]

Hell yeah be nervous! If there was no mystery sound then I'd say don't worry about it but where there's unexplainrd noise there's trouble. I know its a pain buit I would do 3 things:

1. Drain the oil and see if any metal comes out.
2. Pull the valve covers off and take a look at the valve train and look for anything unusual.
3. This is the most painfull- Pull the dist. out and inspect the shaft that goes into the oil pump. Those shafts have a tendency to twist and break. The noise could have been that thing twisting. They can really stretch before they break! The only way to avoid it is to get a billet one.

Hope this helped.

 

[5.0fox]

if i were you i would start by getting a new oil pump driveshaft. they are very cheep and good insurance. i would also do an oil change. comething may have gotten in your oil and sucked up against the pickup tube screen.

 

[Carbed86GT]

Are you running a fram oil filter? They are constructed cheaply (except the black rubber handle that gets people to buy a worthless filter) and are known to cause erratic oil pressure, drop in pressure and oil starvation. If this is the case get a wix made filter from napa.

 

[bsedwebt70-5.0]

My 1993 5.0FI did the exact same thing for a few weeks while I was trying to get it on the road. I would start it up and the pressure would be perfect and then it would drop to 0 for no reason at any given time. Other times I would start it and it would show 0 and I would cut it off immediatly and start it again and get perfect pressure again. I checked the wiring - perfect. I changed the sending unit 2 times - same thing doing. I thought it had to be a bad wire so I did not mind it much. Then when I was trying to set the idle I heard a faint clicking - like lifters starving and I looked in the car and saw that the pressure was 0 when that was happening and it was good when there was no clicking. After pulling the oil pan and examining the rod and crank bearings they were almost all wiped out. Oil pump and all rod and crank bearings were replaced (thankfully it was caught just in time before the crank needed turning etc...) and all is perfect now - no noises, no oil burning, no pressure problems with 10w/30 oil - everything perfect now on the guage, etc.. for well over 1000miles so far. I suggest you stop running the engine and pull the bearings ASAP and check the crank before it is too late.

 

[needforspeed440]

Ok, thanks for all the info. I do have a billet shaft, so I doubt that was the problem. I had recently done an oil change within the last week. I run a motorcraft filter, not fram, I have heard good things about motorcraft. I will proceed with checking the oil and examining the the bottom end.

 

[HISSIN50]

You could grab a sample of oil and send it out for analysis if you wait to drive the car again.

Good luck.