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383 suddenly lost oil pressure

richardgoesfast

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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.
 

Russ69Runner

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

richardgoesfast

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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

70RoadRunnerOilPressure.JPG
 

Russ69Runner

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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.
 

quikbird

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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

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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

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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?
 

Russ69Runner

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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.
 

quikbird

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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

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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

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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

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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!
 
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