No oil pressure
#1
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No oil pressure
Howdy,
I've got a 1991 5.7 liter with no oil pressure. I checked it with a gauge, so I know it's not the sending unit. The engine's been sitting for three years, and there was a lot of solids/sludge in the oil when I changed it.
Can an oil cooler be so plugged up with sludge, just from sitting, that it can't push any oil through? I mean I'm getting ZERO pressure. It's a major hassle getting to that oil cooler.
Thoughts anyone?
I've got a 1991 5.7 liter with no oil pressure. I checked it with a gauge, so I know it's not the sending unit. The engine's been sitting for three years, and there was a lot of solids/sludge in the oil when I changed it.
Can an oil cooler be so plugged up with sludge, just from sitting, that it can't push any oil through? I mean I'm getting ZERO pressure. It's a major hassle getting to that oil cooler.
Thoughts anyone?
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When I put the distrib back in... is it keyed so it's lined up properly for timing? Or is it slotted or splined or something so that it's possible to totally screw up the timing when I put it back in?
#5
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Does the engine start and run? You could always just remove all the plugs and spin it over. Using a primer tool won't be any different. Restricting the oil flow is what makes pressure so a clogged cooler wouldn't have anything to do with it.
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This has happen to me a couple of times where the oil pump seems to have lost its prime or suction ability after the engine has sat idle for an extended period of time. Certainly the best way is to prime the engine thru the distributor, but I really don't like messing with the distributor. What I do is pressurize the oil system thru the oil pressure sensor fitting, standard pre-lube approach (but with a temporary connection). This has a dual benefit, it pre-lubes the oil system and it also backs oil into the oil pump. I think that you will find once the oil pump has some fresh oil in it that your system will pressurize like it should. I purchased a master lube and just use it as a portable unit, although I probably should mount it permanently. If the system doesn’t pressurize instantly, shut down because something else could be wrong. A bad example would be that the draw tube has broken off the oil pump. If I haven’t ran an engine for a while, I will go ahead and pre-lube it before I will even crank in.
Hope this helps,
Andy
Hope this helps,
Andy
Last edited by PremierPOWER; 06-27-2011 at 09:30 PM.
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Since it was sitting for three years, I started out by lubing the cylinders and barring over with plugs out. Then I spun it with plugs out. It never builds any pressure up. I initially thought it was the sending unit, but then I put a mechanical gauge on it and saw that there's no pressure. Tomorrow I'll try pulling the gauge and just putting my finger over the hole to see if any oil is flowing. I suppose I could pull the oil filter and blow pressurized air through the system as well.
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This has happen to me a couple of times where the oil pump seems to have lost its prime or suction ability after the engine has sat idle for an extended period of time. Certainly the best way is to prime the engine thru the distrubutor, but I really don't like messing with the distributor. What I do is pressurize the oil system thru the oil pressure sensor fitting, standard pre-lube approach (but with a temporary connection). This has a dual benefit, it pre-lubes the oil system and it also backs oil into the oil pump. I think that you will find once the oil pump has some fresh oil in it that your system will pressurize like it should. I purchased a masterlube and just use it as a portable unit, although I probably should mount it permanantly. If the system dosent pressurize instantly, shut down because something else could be wrong. A bad example would be that the draw tube has broken off the oil pump.
Hope this helps,
Andy
Hope this helps,
Andy
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#10
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OK, so no ones going to ask about the SLUDGE issue? How many hours on the engine? Was there oil left in the pan? What did it look like? Why would the oil pump loose it's prime if submerged in oil? I'd also avoid removing the dist. Opening up a whole new can of worms. Pull a valve cover and see if there's SLUDGE in them. If so then motor is past due for an overhaul. If not, drain it, flush it, change the oil and spin the crap out of it. Also make sure that the dist is at least turning, if not then something else is going on, bad timing chain etc. Just my 2cts.