99 2500

My 6.0L engine lost oil pressure, so i tore down the front end and found small pieces of metal in oil pump causing the relief valve to stick open. The pieces of metal was from cam lobes wearing. Replaced cam, lifters and oil pump with a stock ls6 pump -- turn over motor without spark plugs to build oil pressure before starting engine, but would not build pressure. I then removed the oil filter and turned over engine and there was no oil making it's way to the filter. What are the chances I bought a defective new LS6 oil pump.

02*C5

iTrader: (1)

Everything mechanical has the possibility and can be defective upon arrival.

You can always take it back and tell the people you bought it from whats going on and get another one. There is nothing wrong with the LS6 pumps many people use them with no problems at all.

I am using a Melling product and many of the guys I know are also using either the M295 or the M296, depending on application. Never had an issue and the one I have is on its second H/C package.

garygnu

did you clean out the pickup tube? could be clogged with stuff.

Pro_built7

iTrader: (9)

Call me stupid---

But is just turning the motor over enough vacuum to cause the oil pump to bring oil up from the sump?

Seems like it would need more rpm to cause suction..?

As in.. when you fire it up for the first 2-3 seconds.

99 2500

Thanks for the response guys, have built oil pressure on many LS engines this way. Infact you can put the oil pump in a container with some oil and turn pump with crank sprocket and watch it pump oil -- so starter speed is more than enough to build pressure. The only difference with this LS6 oil pump was that on the box it had made in Mexico instead of Made in Canada like the previous oil pumps i replaced. Will tear back down and check pump and pickup tube, never thought of it be clogged so good point.

AFASTYZFR1

iTrader: (55)

+1

It will not build pressure just turning it over (wont show it on gauge)......but it will prime things....then start motor and if you dont have pressure within say 10 sec then something is wrong and you need to kill it

99 2500

Have done this many times, it will show about 30 pounds on the gauge. The reason i usually do this is because it pumps the lifters so it's quiet when you do the first start.

AFASTYZFR1

iTrader: (55)

I just put together two motors last week and neither showed anything on gauge while cranking with no spark or fuel......both got oil pressure within 5 sec of starting

maybe you have a 98 and your computer and gauge is different than the 2 cars I did (00-01)

99 2500

Definately not interested in arguing about whether or not you can build oil pressure with just turning over the motor because i've done many times before, just trying to understand the odds of buying a new defective oil pump - which i seem to have done.

AFASTYZFR1

iTrader: (55)

Not trying to argue, just trying to help......have you tried starting motor? have you looked under valve covers while cranking to see if oil is making it up there

I guess it is possible to get a defective pump, but is unlikely

99 2500

I have done better than checking under valve covers, i pulled off the oil filter and turned it over for total of 60 seconds and nothing. When i turn over by hand now there's a sweaking noise come from inside the timing cover so probably definately bad pump. Will tear into it on Friday and see what i find.

99 2500

UIPDATE

Took apart the front end today and put pump in half gallon of oil and turned it over with cam sprocket by hand and it started to pump-- i was like WTF. So i put the engine back together and did the same thing as before and turned over the engine with the starter for 30 seconds and bam 35 pounds of oil pressure. Put the spark plugs in and fuel relay and immediate oil pressure when it fired up -- 45 pounds at idle. Not too sure what happend but certainly am pleased with the results. Thanks for all the inputs.