Low or no oil pressure on new engine, wtf now...

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dano

dano

Evil Handy Man
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I rebuilt my 340 was back in 98. While I did the body work and interior. We broke the motor in, had some issues with the guides bending push rods, fixed the issues, fast forward to late 2007, the cam (Crane) and lifter go flat. From the time I built the motor until now, it has about 8 miles (NOT in 1/4 mile increments) on the engine and some idle time. Yesterday, we broke in a new cam, Lunati VooDoo. Everything went well, had a few rocker a bit loose but no biggie.

One issue, low oil pressure.

I haven't replaced the gauge (mechanical) but at 800 rpm idle I could pull the line from the sender and get a trickle of oil. Plugged in, gauge showed 0 psi hot idle and about 20 psi at 2000 rpms. Prior to the cam I had good oil pressure. When we had the motor apart for the cam replacement, we checked all the main bearings, they looked fine. At the time of the new cam we did the following new.

Lunati cam and lifters
Hughes timing chain
Mopar timing chain tensioner
Melling HV oil pump
new gaskets

Break in consisted of fresh Valvoline 10/30w and fresh Perolator Gold filter.

Could I have a bad oil pump? Is there something about the timing chain tensioner?

PROGRESS Update

Confirmed:

-the plug by the distributor is there
-gauge is good
-Drive shaft gear on pump drive shaft is good.

Looking at in this order:

-oil pump
-#5 main oil plug
 
The bearings were good when it was apart? What did the cam bearings look like? Did the new cam rotate easilly in the bore after install? Like you could turn it by hand? Did you disassemble the new pump and inspect it? Have you used a preoiling shaft to pressurize it to see what you can get for pressure?
 
I had a fresh engine that lost oil pressure all of a sudden,one of rocker arms broke an adjuster screw and it threw the lifter out of its bore,not a good feeling when your engine is running and there is no oil pressure.
 
My dad installed the cam, I wasn't present so i don't know how it rotated, he's no amateur at engine builds, so I know he would have checked the bearings and the new cam. Didn't inspect the pump, that's what we are leaning to, the relief spring. Have not manually pressurized it yet, we wrapped this up at about 7:00 pm last night, so today is theory and cover our bases day.

I will say I have no knocking noises, no smoke, both exhaust pipe are clean, clear and even. But we are not running the engine until the pressure issue is worked out.
 
blown71duster said:
I had a fresh engine that lost oil pressure all of a sudden,one of rocker arms broke an adjuster screw and it threw the lifter out of its bore,not a good feeling when your engine is running and there is no oil pressure.
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Your right. I don't like this at all, this 340 has been a pain in my *** since day 1. Today the passenger side valve cover is coming of for inspection, but so far everything else is good. It did have low oil pressure from the first fire, but it had about 20 psi during breaking.
 
You did right by removing the sender to verify oil flow. And right again about not running it. As a rule, I've always taken the new pumps apart to make sure they are clean and make sure the relief valve works. You may have one stuck open. As long as the tnesioner was installed properly they won't affect the oil pressure. With that HV pump you should have a ton more pressure. Also, when the pump was changed... was the pickup to oil pan clearance verified?
 
moper said:
You did right by removing the sender to verify oil flow. And right again about not running it. As a rule, I've always taken the new pumps apart to make sure they are clean and make sure the relief valve works. You may have one stuck open. As long as the tnesioner was installed properly they won't affect the oil pressure. With that HV pump you should have a ton more pressure. Also, when the pump was changed... was the pickup to oil pan clearance verified?
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We have in the past check the pumps, just didn't this time, figures... Installed the tensioner with the hardware it came with, just took the old cam plate off and bolted it in place. We verified it the first time, but not with the new pump. I have a summed pan, but not the pickup, an area we are checking today, we might be a quart low, we have 6 in now, thing is it make pressure with rpms, just not enough, which leads us back to the pressure spring, were also checking the plug near the distributor in the block........ This is the downside to stalling almost two years on this motor, you forget so much.
 
dirt in the relief valve.

I had a 318 do this out of no where while driving down the freeway of all places, it dropped to 20 psi at 70mph/3000rpm so I pulled off the freeway and so pissed that I just did it angry man style and rev'd it 6000rpm in idle and wahlah! perfect oil pressure again....
 
It's very possible the first cam eating deal put metal into the oil system. Something could have gotten into the new pump. but I'd be looking for 40-50psi cold and a max of 75psi at like 2000 rpm with that pump.
 
moper said:
It's very possible the first cam eating deal put metal into the oil system. Something could have gotten into the new pump. but I'd be looking for 40-50psi cold and a max of 75psi at like 2000 rpm with that pump.
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Well, it had low pressure from first crank, it never went up past 20 psi. Still working to see if its the gauge, but pulling the line while running and seeing how slow the oil was moving doesn't give me much hope on the gauge.

Just confirmed the distributor oil plug is there.
 
dano said:
Well, it had low pressure from first crank, it never went up past 20 psi. Still working to see if its the gauge, but pulling the line while running and seeing how slow the oil was moving doesn't give me much hope on the gauge.

Just confirmed the distributor oil plug is there.
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If you had an open hole where the oil line went while it was running YOU DEFINITELY HAVE A PROBLEM! I'm thinking you left a galley plug out from the very beginning since you never had oil preasure from the begining.
 
SGBARRACUDA said:
If you had an open hole where the oil line went while it was running YOU DEFINITELY HAVE A PROBLEM! I'm thinking you left a galley plug out from the very beginning since you never had oil preasure from the begining.
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No open exterior oil lines that were are aware of, no exterior leaks at all.
 
There is a plug on the rear of the lifter galley that if it was left out would leak oil back to the pan and you would not see an external leak. If you pull the distributor out, you will see where it should be. Use a small mirror or a piece of wire bent at a 90 degree angle to feel if it is there.
 
SGBARRACUDA said:
There is a plug on the rear of the lifter galley that if it was left out would leak oil back to the pan and you would not see an external leak. If you pull the distributor out, you will see where it should be. Use a small mirror or a piece of wire bent at a 90 degree angle to feel if it is there.
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Confirmed:

-the plug is there
-gauge is good

Looking at in this order:

-Drive shaft gear on pump drive shaft
-oil pump
-#5 main oil plug
 
When you took off the old oil pump... was the gasket flattened evenly?
 
moper said:
When you took off the old oil pump... was the gasket flattened evenly?
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There enters one of the problems, I wasn't there for the tear down, and that happened almost two years ago.....no I don't know.
 
hi, did you run oil pump with drill motor before installing motor in car?? just curious is all.
 
68383GTS said:
Did you replace the cam bearings when you replaced the cam?
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No.

perfacar said:
hi, did you run oil pump with drill motor before installing motor in car?? just curious is all.
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My dad said he did, but I don't think he did as I was there when we finish assembled the motor, and he didn't when I was there.

At this point were pulling the pan, pump and #5 main to check for one of the plugs.
 
On the early engines the cam thrust plate seals the lifter oil galleries, maybe it is not sealed? I think the newer blocks use plugs to seal the galleries. Maybe when you changed to the tensioner that it didn't seal the galleries?
 
66fs said:
On the early engines the cam thrust plate seals the lifter oil galleries, maybe it is not sealed? I think the newer blocks use plugs to seal the galleries. Maybe when you changed to the tensioner that it didn't seal the galleries?
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Well, My engine is a 72, is it an issue? Here is what my new plate looks like, do I need a plug? The old set up was the 4 bolt plate and the oil slinger on the crank.

thumbnail.php.jpg
 
1wild&crazyguy said:
dirt in the relief valve.

I had a 318 do this out of no where while driving down the freeway of all places, it dropped to 20 psi at 70mph/3000rpm so I pulled off the freeway and so pissed that I just did it angry man style and rev'd it 6000rpm in idle and wahlah! perfect oil pressure again....
Click to expand...

holy crap, that made me laugh...i'd do the same thing!
 
Maybe I missed it, but what was done about all the metal from the wiped Crane cam? That stuff will get everywhere quick.
 
One lobe went bad. Basically tore it down to the short block, clened and inspected. We didn't find much metal, but I never cut the filter open either.
 
So the crank was pulled and all bearing surfaces were inspected and found to be good? Just wondering. I feel your pain man! Hope it's just the pump and nothing got hurt.
 
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