EPIK

Yesterday I went to start my 2005 V (78k miles) and on the dash it read "low oil pressure, SHUT OFF ENGINE!", and it was reading at zero oil pressure. Does this sound like a pump failure or a sending unit failure? How do I properly diagnose, as I would prefer to not just throw parts at it? Thanks in advance for any info you may have.

ls1247

iTrader: (2)

There's probably some way to check the sensor using an ohm meter or something. If you can't find the spec on it, go buy one and ohm it out. Darkman on the other forum has the service manual surgically implanted in his brain. I don't have access to a manual so maybe post up over there.

These oil pumps have been known to fail but not that often. However, I have yet to read of any sending unit failures but that doesn't mean it isn't happening.

NIKDSC5

iTrader: (10)

Pull fuel pump fuse and remove a valve cover. Crank. See if oil is coming from push rods. If not=I'm sorry.

If so=oil pressure sending unit change. 9/10 it is the sensor

EPIK

Thanks guys. I put a new sending unit in, and still no pressure. Guess it's new pump time! 👎🏽... Sad that the pump fails at less than 80k miles!

DMM

The relief valve gets seized in the open position dumping the oil. I always opt for the LSA/LS4 oil pump. It's high pressure/volume and is cheap through the dealer.

EPIK

Thanks! I will look into that tomorrow! My buddy recommended a Melling high volume with a "blue" spring or something like that

itsslow98

iTrader: (18)

I use Melling HV in LSX builds. I would venture to say its probably just a sensor issue though.

EPIK

Which sensor though? Because I changed out the sending unit this evening.

itsslow98

iTrader: (18)

Sorry I overlooked that you replaced it. You could hook up a mechanical gauge and try that. Im sure someone has one you could borrow. Not sure how fast you need it back but it may be worth trying before tearing into it.

EPIK

No problem. It's no rush, I daily drive my Tahoe, so the V can wait until i research a little more. Thanks for the help

EPIK

So... Oil pump failure it is. Should I get a Melling, or GM performance pump?

NIKDSC5

iTrader: (10)

Melling.

bmylez

iTrader: (3)

How did you verify?

EPIK

Changed the sending unit yesterday, still didn't fix it. Thought maybe my computer could be acting up. Disconnected the battery overnight, hooked it back up, and started it this morning and I heard slight valve train noise & shut it off immediately. Has to be the pump.

itsslow98

iTrader: (18)

How long has it been cammed? Could it be a pinched oil O ring thats finally let go? I didnt realize you were cammed until now.

EPIK

I bought it cammed from a buddy of mine in early 2011, not sure exactly how long it was in there prior to me getting the car, but I've owned it since 52k miles, and it has 78k on it now. The car has never missed a beat until this happened.

EPIK

Ok fellas. I'm getting ready to get this fixed. My mechanic suggested I upgrade the timing chain at the same time, as he said the LS6 chain isn't very good, versus other newer LSX timing chains (like the LS2 chain I think he mentioned)? Is changing the chain necessary at only 78k miles? Also, I was thinking about saving a few bucks & going with the GM performance oil pump, is this pump any good? Should I change the water pump as well?

EPIK

This is the pump that was recommended by a buddy... http://www.summitracing.com/nv/parts...make/chevrolet

DMM

LSA/LS4 pump, new o ring, LS2 chain, water pump and timing cover gaskets. $200 or less from the dealer and be done with it.

EPIK

Ok Thanks.