Danspeed1

iTrader: (1)

Just got my 2005 Vette back together in august after a 1 year build that cost way too much blood sweat and overtime. I fear it may all have to come apart this winter. In short, I am running ported heads, cam, morel lifters, M112 supercharger, and Methanol Injection on a stock bottom LS2. For whatever reason at the time I rebuilt the engine I opted to stick with my stock 40K mile oil pump (big mistake). For the last 5K miles the car has run decent, with no major issues. I have electrical gremlins however. Since day 1 of rebuild I noticed that when the engine was cold it made a pretty loud ticking sound; but oil pressure cold is at 45 psi idle. I was told it was the morel lifters. Last week I was driving the car when the low oil pressure light came on. I quickly shut the car. And then restarted it. Pressure was back to 40 psi. I figured it was an electrical problem. Today was last ride before I put it away for winter. 28*F outside; I went out and started her up. It was shuttering pretty hard but its really cold so I didn't think anything of it till I looked in my rear view mirror and noticed a huge black cloud coming out the rear of the car. Never seen that before! Just around that time I looked down at the oil pressure gauge and noticed 0 psi. Killed the car. Total elapsed time it ran was for about 12-15 seconds. I opened up the oil cap and with a flashlight looked in. It was pretty dry. I had my father restart the car once to see if oil was reaching the head. Ran it for about 5 seconds... nothing, however now we had oil pressure... 28 psi. Started the car a couple seconds later, car still dead cold 26 psi. Gave it a quick rev and got it up to 32 psi. Normally it would be in the 50's. So how F***ed am I? Pulled the dipstick... milky substance on stick and a couple of visible metal flake particles. Thoughts?? Bad oil pump? something else? How bout those bearings? Such luck.....

DG

Danspeed1

iTrader: (1)

Although I have never had the car run as rough as it did and blow smoke the way it did, I have had great oil pressure till the minute I put it away the last time I drove it. Is there any possibility a bad pressure sensor could cause the result above (Zero and/or very low readings). How do I test this system so I know for sure? Definitely don't want to keep starting it.

DG

DMM

I have fixed three LS motors that had valve noise with oil pumps. One has been regular "sewing machine" noise, and the other two have been valve and lifter noise.

The last one was my cousins well maintained '03 Denali XL with 119k miles...started with valve noise and quickly escalated to a solid knock. Shop said it was a rod, and quoted for an engine. Sounded like a lifter to me, and I had the same noise (intermittently) on my own Suburban.

Long story short, it had 40 PSI of oil pressure cold and hot. I installed the LS4/LSA oil pump and now have 75 PSI cold and 60 hot. The LS4/LSA pump has fixed all three that I have installed them on.

I don't know what happens to the oil pumps that cause them to lose flow internally, however it seems that they cannot supply the rear of the engine with enough oil.

And to answer your question, the OE oil pressure sensors are junk and usually read very low when they fail. I opt to upgrade to "Standard" aftermarket sensors as they are made from brass and are much stronger than the OE cheap pot metal/aluminum sensors. Put a gauge on it if in doubt.

filmjay

I had a similar issue...0 oil pressure, bad knock...was a stuck lifter for me, caused by a broken valve spring. Doesn't matter if you use the highest quality parts...sometimes sh*t happens.
I'd pull the valve covers and check, at minimum.

...and I've got a SD ported oil pump up for grabs if you want it.

And those electrical gremlins, I would say, is from the extra drag on the alternator caused by that supercharger system. Most blower setups should have a matched alternator pulley included...but nobody has ever thought to include one in any LS setup I've seen...guess it keeps us coming back for repairs. LOL!
I know because I just sold MY supercharger system and am going back n/a because I got tired of the electrical headaches. My alt was continuously, undervolting, causing the regulator to work overtime to keep up and finally burn out...took me 3 alternators to finally figure it out.

Danspeed1

iTrader: (1)

Thank you for the up lifting post. I was expecting a one line, "your engine is done" and thats about it. Glad to see their is a possible fix for this. The interesting part about the tick is it only lasts till the oil is at about Coolant temp is about 120*F and then the motor is dead silent for the remainder of the day. I don't even have the sewing machine noises. The oil pump is the original factory pump and the engine never made any noise before the morel lifters. My only concern is if a portion of the motor is not receiving oil then wouldn't that mean oil starvation on some of the bearings? However for that to be wouldn't oil pressure have to be normally low? Prior to yesterday I was getting 45 psi readings cold and 32-34 hot. That seems pretty average to me. Even with all the smoke and bs yesterday the engine was not ticking or knocking, it was just running rough. Either way, the oil pump is getting replaced this winter at the very minimum, even if it turns out to just be a sensor.

Is there another port I can use to test for oil pressure with a mechanical gauge? And how much of a risk do I run turning this thing over again to check it?

Yea, I figured that out a long time ago. To make matters worse I have an innovators OVERDRIVE pulley on the car. The service electrical system light is on intermittently and thats likely because even at idle the cars producing 14.5 volts. I appreciate the offer on the oil pump. I will keep it in mind. I want to do a little more research first.