383 suddenly lost oil pressure

[richardgoesfast]

Was idling 1970 RR in garage and it was cold and stalled out. Which is typical until it's warmed up. Fired up again, and watched dash oil pressure go up to 30 or so, then needle just slowly fell back to nothing. Shut it down.

Next day, fired it up everything normal. Warmed it up. Started blipping throttle. Same thing, oil pressure gauge falls back to nothing (left side of gauge obviously).

Some history: this car is in process of getting registered, and has been in garage for 2 years not on road. Before that it was in garage for another 3 years or so (previous owner). I did change oil last year, but forgot to change filter, so it still has the old Mopar filter unit. That's about all I can say. Everything else seems normal. Fires right up, settles down to idle, no mechanical sounds or weirdness.

If anyone has any ideas on this one, pls. post 'em.

 

[droptop]

Put a mechanical oil pressure gauge on it just to rule out dash gauge issues.

 

[Russ69Runner]

Change the oil filter.

 

[richardgoesfast]

Put a mechanical oil pressure gauge on it just to rule out dash gauge issues.

Don't have one, but gonna get one tomorrow. Thanks.

 

[richardgoesfast]

Change the oil filter.

So the oil filter change sounds like a good idea? Not difficult. Will report back on this.

 

[Russ69Runner]

Would run an Oil pressure gauge also as mentioned before or replace your. As per droptop's suggestion.

 

[69hemibeep]

Got enough oil in it?

 

[richardgoesfast]

Hey guys - installed new oil filter, fired it up, still no pressure. Gauge doesn't move at all. Next step is get mechanical oil pressure gauge, want to make sure I have the correct place to hook it up, please see attached photo. Appreciate it if you could let me know if I've got the right bolt or nut to remove.
Also wondering if that dirty looking wire off the bell could just be corroded at connection and not sending a signal, dunno I have no clue.
Thank you thank you

 

[Russ69Runner]

Have you tested the oil pressure bell. OHM it and see if it show's any thing. Yes that wire connection look pretty bad. Try clean it all. Maybe bad connection. But figure the bell dose need replace.

 

[droptop]

Remove the plug and put mechanical gauge in there.

 

[quikbird]

Have noticed an occasional problem with what almost appears to be a vapor lock when change oil filter. Some times have needed to crack loose the filter for a few seconds and seems to solve the problem

 

[richardgoesfast]

Have you tested the oil pressure bell. OHM it and see if it show's any thing. Yes that wire connection look pretty bad. Try clean it all. Maybe bad connection. But figure the bell dose need replace.

What does that mean OHM it, as in Ohmeter I'm thinking, if so how do you connect it?

 

[richardgoesfast]

Have noticed an occasional problem with what almost appears to be a vapor lock when change oil filter. Some times have needed to crack loose the filter for a few seconds and seems to solve the problem

That's an interesting idea, I was thinking something similar in back of my mind. Doesn't a flood of oil come out if you loosen?

 

[richardgoesfast]

Remove the plug and put mechanical gauge in there.

Gotta get the gauge first, but thanks it's good to know I found the plug.

 

[Russ69Runner]

Yes ohm push though the wire connector with nothing hooked to it then ground to block. See if you have any resistance at all. But looking at the age of it would say you just need a new one. Just my thought. Yes a new gauge would be the best idea. Or a back up for sure.

 

[69hemibeep]

Turn the key on, ground that wire see if the gauge goes up.

 

[quikbird]

You can get some oil out. Don’t open it far. Just crack it slightly. Just enough to let whatever air is causing blockage out. Have had to do this several times after changing oil

 

[dbc105]

This happened to me once on a 383. Since the pump is so easy to install I put on a new one and got pressure. Took the old pump apart and the spring had broken into 2 pieces. Just old age I guess.

 

[richardgoesfast]

You can get some oil out. Don’t open it far. Just crack it slightly. Just enough to let whatever air is causing blockage out. Have had to do this several times after changing oil

Got it. I will definitely keep this trick in mind. Thanks.

 

[richardgoesfast]

This happened to me once on a 383. Since the pump is so easy to install I put on a new one and got pressure. Took the old pump apart and the spring had broken into 2 pieces. Just old age I guess.

So they actually can just give up with a broken spring. Damn good to know. Thanks!