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Lost oil pressure

R

RustyRed

Active Member
I was taking the boys in the Stang over to the local car club meet tonight.

Oil pressure was fine leaving the drive way. About a quarter mile up the road though I look down and there was zero oil pressure. Pulled into a parking lot and shut it down fast. Got out and checked for leaks...I changed the oil last night so I thought maybe I had forgotten to tighten something, hey it happens.

No oil leaks.

I waited about five minutes and start her back up and there was oil pressure again. It was lower than usual but at least some pressure. It was on the very low end of the "normal" range on the guage but it was enough to feel ok about limping the quarter mile home.

I am thinking maybe there is crap in the pan clogging the screen on the oil pickup?
 
I agree with the others that you need to check sending unit. Or better yet install a mechanical gauge to be sure.
 
Doing some checking this morning and one thing I do know is my sending unit looks pretty old and crappy. Probably going to replace it either way since I can get the part from Mustang Mania for about $12. I wonder about Johns Mustang sometimes...he wants over $20 for the same part, Virginia Classic is $13 but wants a minimum order of $20 and I don't trust CJ Pony parts to not back order me based on some past experience. Good news is if I call Mustang Mania tomorrow I'll have it Tuesday since they are just across town.

Will have to check the gauge also at some point.

More I think about it, it was more like the gauge just went dead and probably still had pressure. But it gave me a bad flash back. Years ago I was on a two lane pretty much in the middle of no where in an '82 F150 I had in college. Never did figure out if it was junk clogging the screen or a bad pickup or bad oil pump or what but in that case oil stopped getting in the motor and ended up rebuilding the 302 in it thanks to that failure.
 
Check oil pressure with a mech. gauge first.

Oddly, we've had some unusual oil problems around here lately also....

The pump pickup tube fell off my sons car a couple months ago. Simple fix, but WTF?

My buddy owns a '66 Coupe with a built roller 302 motor. Last time we went for a cruise, he lost oil pressure. He dropped the pan and found an oil gallery plug in the bottom and is pulling off the FEAD now.
 
When I first put my 429 together, I had a HV oil pump. I had great oil pressure when cranking but once it started it dropped to zero. I put a cheap mechanical gauge on the engine to verify because I already changed the sending unit and instrument panel voltage regulator and the gauge check out okay. Sure enough, the oil pump made pressure during cranking but nothing after start-up. I even pulled the distributor and ran the pump wuth a drill, it made pressure then. I eventually dropped the pan and replaced the pump. Only thing I can figure is the pressure relief spring must have been "weak" and when the pump began to make real pressure it would go into by-pass mode and just flow oil but no pressure.
The point is, check with a cheap mechanical gauge just to be sure, weird things can happen!
 
I'll check it with a gauge.

Mine dropped all pressure. When I let it sit for five minutes it came back so we went on to the meet.

Coming home the pressure was fine at first, where it usually is in the middle of the "normal" range on the gauge. However, by the time we got home (about a 5 to 8 minute drive) it was just barely in the normal range...sitting on the line on the low end.

Could just be the sending unit but want to make darn sure. As I learned with my old F150 no faster way to need an engine rebuild than letting an oil pump or pick up go bad.

I have been planning on doing something with my motor anyway but now isn't a good time.

Wife's paycheck runs out on Tuesday. She has been working with a consulting firm but they haven't had any billable work in over a month. Last week's pay and the first two days of this week are unused vacation time. After that I guess we file for unemployment. She has a second interview with a new firm on Wednesday but trying not to make any expensive plans till we find out for sure what's going on there. Prospects are really good though. She had done some work on a mutual client with this firm a while back and they were trying to hire her then. When she sent the dude a resume late Friday before last he called her back pretty much first thing Monday morning. She did the phone interview with the HR person the other day but waiting till Wednesday for the managing partner to get back in town so she can go in for a sit down interview. May drag my feet a little and if she gets the new job this week I could use it as an excuse to move ahead with my plans. Already have ported GT40 heads, intake, valve covers, etc. Just need to get the block and have it all assembled. I might even be able to assemble it myself but might be a bit above my pay grade.
 
I might even be able to assemble it myself but might be a bit above my pay grade.
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I doubt that. Engine assembly is not that difficult. Buy yourself the "How to Build Ford Engines" guide/hand book and have at it.
 
On the plus side of things I already own a torque wrench, LOL!

Years ago I dated a gal who's dad was a preacher (of all things) but had been working on cars his whole life. He used to do a lot of work as charity for the parts cost for various people. Back in the day I helped him rebuild a few engines but it's been a few years. I used to go over and help him every chance I got just to learn.

I've seriously considered doing it myself. Already have the how to book and even bought a pretty good video from a local guy online a while back about "how to rebuild your small block Ford." The video brought back memories since he literally starts the video with a bare block and walks through it step by step with the camera rolling.

Several times I have seen an ad from a guy that has a 302 roller that is already machined, fluxed, etc and ready to build. He wanted $375 for it but that isn't a bad deal really. It'd cost that much to have one machined.

Main thing I am not certain about is moving the dip stick to the front if I were to go with a newer 302 and there is something to do with the steam holes when putting GT40s on but can't recall exactly what the deal was there.
 
You would end up changing the timing cover anyway. The later model covers do not have the opening for the fuel pump as they used electric pumps, the new cover will have the fuel pump opening as well as the required oil dipstick inlet. Unless of course you want to convert to an electric pump...
 
Main thing I am not certain about is moving the dip stick to the front if I were to go with a newer 302 and there is something to do with the steam holes when putting GT40s on but can't recall exactly what the deal was there.
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The dipstick relocation is a no-brainer. If you have the unused old dipstick hole in the side of the block, simply hammer an appropriately sized wooden dowel into it.

The GT40 Head steam holes is a well documented procedure. Grab some on-line pics/instructions and then bust out the ole hand drill and have at it.
 
I'll keep an eye out for the machined block I have seen advertised a few times. The guy isn't far and I e-mailed him a question about it so I'll see if I can dig up his e-mail. Doing all or even most of the assembly myself would sure make it cost effective. Heck, I could probably sell my existing motor for pretty much the cost of the block. I had a guy that offered me $300 for it back in May.

In the mean time, my new sending unit should be coming today.

Now the "stupid" question(s). If I run over to the auto parts today, don't I hook the mechanical gauge up where the sending unit screws into the block? Also, what sort of range pressure wise should I be looking for?
 
hook the mechanical gauge up where the sending unit screws into the block? Also, what sort of range pressure wise should I be looking for?
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Yeah, I guess that's a problem. You'll need to get the old threads of the extension out of the block first.

Warmed oil pressure should be at least 10 psi for every 1000 RPMs.
 
"RustyRed" said:
Now the "stupid" question(s). If I run over to the auto parts today, don't I hook the mechanical gauge up where the sending unit screws into the block? Also, what sort of range pressure wise should I be looking for?
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You don't have to remove the "unit" from the block. Your gauge runs into the unit that screws into the block. Simply disconnect the old and hook up the new. The main thing to watch out for is the compression fitting on the back of the mechanical gauge. It's real easy to "crimp" the line when installing/tightening and not getting an accurate reading. I'm running about 60 psi while driving and about 30 at idle. Dave said "at least 10 per 1000" but don't be surprised if you get more.
 
"blue65coupe" said:
You don't have to remove the "unit" from the block. Your gauge runs into the unit that screws into the block. Simply disconnect the old and hook up the new. The main thing to watch out for is the compression fitting on the back of the mechanical gauge. It's real easy to "crimp" the line when installing/tightening and not getting an accurate reading. I'm running about 60 psi while driving and about 30 at idle. Dave said "at least 10 per 1000" but don't be surprised if you get more.
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If he is running the original sending unit, yes -he'll have to remove that. That is an electrical sender grounding through the block - operating the factory gauge.

Just unscrew that bell looking sender unit and screw in the new compression fitting into the sender unit extension.
 
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