Seems to be a common theme here
-- guess it's time to get a mechanical oil pressure gauge.
Occasional Oil Pressure Light for 2-3 seconds in my 318. Should I panic?
- Thread starter vames
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Seems to be a common theme here
-- guess it's time to get a mechanical oil pressure gauge.I doubt the oil sender is defective or reading inaccurately, if it was the light would probably not come on most of the time when you take a sharp turn, or in the streets <40 which happens as you constantly brake and accelerate and the oil moves back and forth in the pan uncovering the pickup. The light would be coming on intermittently with no rhyme or reason. I would be willing to bet the pickup is too far away from the pan, and when you take a hard turn freeway entrance, or brake or accelerate too fast, the movement of the oil in the pan uncovers the pickup. If I were to take a guess, the PO lifted the car using the oil pan, bending both the pan and the pickup tube. When the new engine was installed they used the old pickup tube and pan. I am willing to bet anything you want that, even though the pan is still bent, they probably tried to straighten it out as best they could before they installed it, but they never tried to straighten out the pickup tube, as when they looked at it probably looked fine, you probably could not tell the pickup was bent if you just looked at it. So, they assembled the engine with the straightened out pan (which still is probably bent a bit) and the completely bent pickup tube.
Well stated, and I am starting to go in this direction. If this was a signal problem (the sender) I suspect I would be getting more weirdness in the operation, but it's mostly acting normal (oil light on for 2 sec when I start the motor, off during stationary idle and highway driving). I also suspect that putting more oil in created less of a chance of uncovering the pickup while oil is sloshing, but doesn't eliminate it (thus this very occasional problem). And the explanation that the installer might have pounded the dent in the pan down a bit but was unaware of the bent pickup makes a lot of sense. I'm gonna pull the oil pan, pound out the dent a bit further, inspect the pickup, and if it's fine, bend it until it touches the bottom of the pan.
While I'm convinced about this as you are, I'm still going to get an oil pressure gauge because dummy lights are for.......dummies.
Step one should be to check the pressure with a mechanical gauge. It takes ten minutes to hook one up, you dont need to plumb it through the firewall and mount it just for a simple test.
Dan the man
Well-Known Member
There's suppose to be a clearance of a 1/4" to 3/8" between the pickup tube and the pan
Demonic
Well-Known Member
Without a pic of the dent - if the pan was whacked enough to hit the pickup, it could be cracked, maybe up at the threads at the block - thinnest spot is the pipe threads.
No there's not. The factory service manual clearly states the pickup should touch the pan.
The dent wasn't that deep (probably at most 1/4") and it ran fine for the 25+ years I had it on the old engine. But as HSDemon said, the guy who installed my engine might have popped most of the dent out of the pan but didn't bend the pickup back down to meet it. Nonetheless, I'm going to inspect everything very closely down there.
I can see where some people might think that the pickup should not touch the pan, since some of the racing applications do say 3/16-3/8" off the bottom (see Moroso below).
But as I posted before, the factory manual does indeed clearly state that the stock pickup should be touching the stock pan in a stock setup.
Rat Bastid
Dunamis Metron
No, there isn’t with a stock pan and pick up.
Rat Bastid
Dunamis Metron
Right. That’s with a pickup designed to be that far away from the pan. There shouldn’t be any confusion over this after 50 years.
I got out the tape measure and measured the sump to the rail on the pan then measured the bottom of the pick up to the pan rail. If it touched good. If there was a 1/4" gap, good as well. Not rocket science here. The pick up is submerged in a few inches of oil at rpm and the hole in the pick up is where it enters.
Dan the man
Well-Known Member
I'm confused here, I googled it and looked it up in my mopar engine building catalog and it showed a clearance for a stock pickup and pan, but you guys have the most experience so I trust your word
This from a different thread but makes sense. Mopar probably just wanted them to be snug in there so they didn't bounce around and deform or crack or rattle against the pan.
Whether or not a "not touching the pan" pickup is my problem remains to be seen. But it is one of the first things I'm going to look at.
Just a thought: I might even take out the drain plug and put the bore scope in there to see where the pickup is sitting.
ir3333
Well-Known Member
My oil light would come on intermittently...scary when it stayed on! I pulled over and the engine was idling smooth and not overheating so i just drove it home.
I screwed in a new sending unit and the oil light never came on again.
I'd try that first if i was you...10 minute job and a few bucks!
I screwed in a new sending unit and the oil light never came on again.
I'd try that first if i was you...10 minute job and a few bucks!
Rat Bastid
Dunamis Metron
What’s confusing? The OE pickup is designed to be touching the pan. If you leave it .250-.375 away from the pan it will not pick up the oil off the bottom of the pan.
There is only 4 quarts in a stock pan. 5 quarts in the system. There is one in the filter, one is the system and 1-1.5 quarts fighting it’s way to get back to the pan. Plus there is some oil caught in the windage around the crank.
That means that there is about 1-1.5 quarts of oil in the pan at most at any time. And that’s not accounting for hot, thin oil moving in that cavernous unbaffled pan.
Doing the math says that the engineers who designed this **** had at least a clue as to what they were doing. That’s why they designed the pickup to touch the pan.
At this point it time, I can’t believe this is even a discussion let alone the argument that it is.
This is SETTLED fact. If you are using an OE pickup it MUST touch the pan.
Any other dimension is WRONG.
Challenger/Dart Service Manual 1970
Dan the man
Well-Known Member
I wasn't arguing about it. I just simply started what I googled and what Chrysler's engine builder's manual said, that just goes to show that not all engineers know what they are talking about.
I was just going to suggest a bore scope but you beat me to it. From my experience the stock pickup is usually just a hair off the bottom of the pan. Almost touching but not actually making contact.
my68barracuda
Well-Known Member
Agree that the pick up is intended to be in contact with the bottom of the pan. For those that think a little clearance at the pick up to pan can help oil flow, it is easy to do that. Simply spot weld a couple of washers to the bottom of the pick up. Depending upon the thickness of the washers that you choose you can get .180 to .250 clearance easy and still have the pick up in contact with the oil pan.
When I first got Vixen, she was exhibiting the same type symptoms. I was certain of what it was though, and I was right. After pulling the engine and removing the pan, it had a good 1/2" or more of sludge on the bottom of the pan. I cleaned it all out and just for giggles, since I had them, I put all new bearings in the bottom end, new oil pump and new timing set. That was the original 170, which I have tucked safely away in a rolling dolly in the shop ready to do battle again if necessary.
Ummmm.....what?!
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