D6c cat loss of oil pressure

[Scrub Puller]

Yair . . .

You actually ran it for twenty seconds?

What can I say? . . . . this is a copy and paste from a post up thread of mine . . . . . .

With a strange and unknown engine with assorted bolt on bits and pieces I have been known to hook up a little gear pump and pressurize all the galleries and crank before bolting on the sump.

At very least I would decompress it (or pull injectors), line up some spare batteries and check it makes and maintains oil pressure with the starter . . . check for flow anyplace that it should drip. That's me though, I'm just a bush mechanic.

Cheers.

 

[Steve.ahlgren85]

Probably more like 10 seconds .When a new oil pump is installed,does it have to prime with oil before it starts pumping oil?I took the elbow on the engine off ,no oil in the elbow!!

 

[Hobbytime]

ill ask it even though im sure you did...but did you fill the engine with oil? dont laugh, I had a friend who toasted a brand new rebuild of a 396 chevy big block, we jumped in his car and he took off and after about 15 minutes of beating the heck out of it, he quickly pulled back into his driveway and stated.." dam, I didnt put any antifreeze or water in the radiator"..that was enough to warp the heads and screw up the rings.....he wasnt a happy camper...

 

[DMiller]

The pump should have been pre-lubed prior to engine assembly, packed with either white lithium grease, filled with assembly lube or the engine pressure lubed prior to start as that would fill the gear pump. Did you use assembly lube on everything, pistons and rings(oil), bearings, camshaft, etc.?
Twenty seconds does not sound long but an engine idling at 500+ rpm has plenty of time to rub away assembly lube and start pulling babbitt.

 

[kshansen]

We never bothered with priming new pumps, just coated pump parts with a little oil while assembling them. Most engines we just spun over with starter a few seconds to get oil pressure then let them start. Sometimes when it was available we did plumb in an air powered barrel pump to force feed the oil galleys. Other times we might crank it over with valve cover off to let us see that the rockers were getting oil.

Even 10 seconds running under no load with no oil pressure would scare me.

 

[Scrub Puller]

Yair . . .
All my operating life (in an era when heavy equipment had mechanical fuel shut offs) I liked to at least see the oil gauge flick before hitting an engine with compression and fuel.

According to Gardner diesels it is a very different lubrication scenario between an engine running at idle and the crankshaft being driven with the starter. . . in the latter scenario (if the engine is decompressed) the only load on the reciprocating journals is basically the weight of the assembly and the friction in the bore . . . not so when its running.

The UK manufacturers (in that era)were absolutely anal about prelubrication. Many the larger units were furnished with hand pumps to pump up pressure before a start. They stress that just a few revolutions of a heavy crankshaft laying on the bottom of it's clearance with no film of oil is enough to "wipe" a bearing . . . perhaps not sufficient to cause an immediate failure but it would materially affect the life of the assembly.

As mentioned by Kshansen a ten second run with no oil pressure would really bother me to the extent that if it was proven that in fact there WAS no oil pressure I would dismantle that bottom end just for piece of mind.

Once the engine was running the sometimes messy task of lifting the rocker box lid to check for top end lube was standard practice


Cheers.

 

[Steve.ahlgren85]

First things first, yes oil and filter are fresh.I guess stranger things have happened. I don't know if new oil pump is faulty or just needs a little more time to pressure up!I don't want as another failure, so will drain the oil and pull the pan off ,check for pump malfunction. I doubt I will see anything wrong. It bolted up without a hitch. that's why this is going to be a rotten sleep nite. I don't have any way of pressuring the engine,wish I did!The engine is a longblock 3306 caterpillar engine, added my fuel pump and oil pan.I didn't add any lubricant to the crankshaft and pistons,maybe should have. I also added a new oil pump.Any other ideas, short of dropping the pan??THANKS for the response

 

[Steve.ahlgren85]

The only prelubing that I did, was to fill the oil filter with oil.

 

[oarwhat]

On a marine site I'm on some guys just use an outboard motor squeeze ball to prelube an engine. I would beg borrow or buy some kind of pump to prelube it. I'm not an expert but 10 seconds with assembly lube doesn't bother me much. I'm sure many engines have seen more time than that before getting pressure. Cold engines don't get lube that fast and assembly lube is better than oil that has been draining off the bearing for weeks or months,

 

[Steve.ahlgren85]

7.5 gallons of oil in the crankcase, wouldn't that completely submerge the pump and prelude it?Also, the temperature here is in the 40's, would that delay the oil pressure rise?THANKS

 

[kshansen]

I don't have any way of pressuring the engine,wish I did!

Well for the time and money you already have in to this engine how about this:
http://www.harborfreight.com/12-gpm-air-operated-barrel-pump-93755.html

It's not like you won't find a use for it next time you change oil in something.

Might be worth hooking it ups while pan is off for a few seconds to see where the oil come out. A bit of a mess but so isn't a pile of metal in a new engine.

 

[Steve.ahlgren85]

Just had a thought,would it work to add another two quarts of oil, remove the rocket cover,add pressurized air to oil pressure port in the block,watching to see if oil comes up and circulates ?

 

[kshansen]

Just had a thought,would it work to add another two quarts of oil, remove the rocket cover,add pressurized air to oil pressure port in the block,watching to see if oil comes up and circulates ?

If I'm reading this right all I see this as accomplishing would be to blow any oil that might be in the oil passages out. If anything this would make it even harder to prime the lube system.

 

[DMiller]

Too easy to rent/borrow/build your own pre lube can, then do it right. Mine is a old truck air tank with a welded in pipe nipple and cap, it has a air shrader valve where I only apply 10-15# air to it as doesn't take a whole lot to force oil thru the engine.

 

[fast_st]

Not sure if its possible or if you already pulled the pan but send some oil backwards down the outer filter port so it settles down atop the oil pump. An oil pump soaked with oil really should prime itself in a hurry.

 

[Steve.ahlgren85]

I think I can make something to work. I haven't pulled the oil pan off yet, I am avoiding that as long as I can. I like the idea about forcing air down the filter base. When adding air pressure in the oil port, is oil added at the same time?THANKS for all the great ideas,

 

[Steve.ahlgren85]

The ports on my block are above the oil level in the engine. Should oil be added above the port to force it upward under air pressure?

 

[fast_st]

Lots of fancy ideas! see if your oil filter has a check valve in it maybe. I'd pull the oil pressure sensor, take a quart bottle of oil with a gear lube spout on it, stuff the spout into the sensor hole and stab a little hole in the bottom of the oil bottle, put the blow gun in there and give it a little puff until it kinda rounds out nicely.

 

[Steve.ahlgren85]

There's no oil coming from the engine elbow connected to the oil line up to the pressure gauge

 

[DMiller]

Is easy enough to check a pressure gauge, they usually don't care fluid or gas. Take your shop air hose, regulate it down to 30-50#, attach that to your oil gauge line at the engine block connection end. VERIFY the gauge works.