-URGENT- Low oil Pressure!

[ar0ck]

During the begining of the week, I was driving down rt. 208 going home @ night. I accelerated rather hard on the on-ramp and I noticed it was lacking some power. As I was comming to my exit I noticed the idle was rough when i came to the stop sign and I started to hear a tapping noise, and all my guages lit up and the oil pressure dropped a little bit. I pulled the car over and turned it off imedietly I noticed the idle was rough when i came to a stop sign so I got underneath and noticed that the 02' sensor managed to disconect itself from the extensions. So I figured it was safe to drive it the next block or so to my house.

I reconnected the sensor before I left for school today and the car was fine. I started driving and noticed it was feeling very weak in power, and the closer I got the school I noticed the oil pressure on my dash was staying steady at 1/4 which I would assume is 20psi which is normal at idle but not at cruising speeds I was driving and the needle didn't change untill i came to stops where it would drop drastically. As soon as it dropped a hair above 0 the "check gages" would come on and the idle became really rough.

One serious thing I also noticed was excessive vibration in my clutch pedal.

I hope to god I didn't spin another bearing or damaged it. I checked my oil and the color was very clean as I just changed it maybe 2 weeks ago so I put in some oil in it because I noticed the stick was reading low on the operating zone.

Any suggestions?

It has a fairly new GM oil pump, but the sizing is for a stock LT1. Could the oil pump have failed causing an irratic idle?

[phillyry]

I would start by testing the oil pressure sending unit

[JSPERFORMANCE]

I would check the actual oil pressure to verify first but it sounds like a bottom end problem and the erratic idle is caused by the low oil pressure not being able to hold up the lifters thus not opening the valves at the correct lift / duration.

[Tru2Chevy]

First thing you should do is prolly buy a real oil pressure gauge. Don't rely on the stock gauge or sender for accurate readings.

Is there a tapping noise coming from the motor when the erratic idle starts?

- Justin

[WildBillyT]

As above, test it with a real oil pressure gauge. You wouldn't happen to have bought one of the GM branded Melling oil pumps, did you?

[ar0ck]

It was a GMPP one, it wasn't the larger one as I hoped it would be. I'm not sure if its one of those Mellings, I have no idea how to tell.

How can I test oil-pressure, like where does it hook up?

So far there aren't any tapping noises from the motor, but I do have some y-pipe leaks so maybe I'll tackle those first and go from there to narrow down a source.

The only thing preventing me from getting a 396 is my wallet.

[Tru2Chevy]

Josh's description for the rough idle makes perfect sense, but every time I've seen that happen, there was a distinct tapping noise to go with it.

The LT1 uses a standard SBC pump, correct?

I think there is a spot just above where the oil filter screws into the block where you can tap in an oil pressure gauge.

- Justin

[WildBillyT]

Check this out, see if it is applicable to your situation:

http://www.ws6zxr.com/showthread.php?t=35629

[NJLT1SS]

What you are describing sounds just like what I experienced when I spun a rod bearing on my stock bottom end.

[ar0ck]

This is gonna be the second bottom end I've been through. I can't afford a new motor. (I probably could have bought a turn-key with the money i've spent so far)

[Pampered-Z]

Few things:

This may sound bazzar! But what volts is your alternator putting out? When mine went bad as was putting out 11vlots my dash lights and gauges went nuts?

I'd drain the oil and check it for any shavings?

What filter are you using? for some reason not all brands seem to work the same on the LT1s. So when you change the oil install a GM filter.

Does the oil pick up bolt to the pump? or was it tacked on? Could it be loose?

As already said. Replace the oil sending unit and it's a goof idea to install a mech/ one. Just above the oil filter is a plug you can remove to install a mechanical oil pressure line. Make sure you wrap it of run it so it doesn't melt on the header!

What cam are you running? Some people have damaged the cam/ oil pump drive gears or even the plastic part that holds the pump drive in. Wonder if it can be slipping or damaged?

JB

[ar0ck]

This may sound bazzar! But what volts is your alternator putting out? When mine went bad as was putting out 11vlots my dash lights and gauges went nuts?


Thats so crazy its possible, because I did find myself at a stop sign and the power was surging like crazy, and I would only get all the guages to go up when I blipped the throttle and I did hear a humming noise as I was driving.

I'm running a CC306. I snapped the oil pump driveshaft the first time, so another GM one was put in by Stage 1 who told me that was the best replacement.

I'm going to check my altenator first, then I'll go to check the oil. I'm currently running an AC Delco oil filter, I double checked on the tightness the other day and there are also no oil stains or usnuauly drips from the motor. I power washed the area when I had the motor out last.

[Ian]

Thats so crazy its possible, because I did find myself at a stop sign and the power was surging like crazy, and I would only get all the guages to go up when I blipped the throttle and I did hear a humming noise as I was driving.

I'm running a CC306. I snapped the oil pump driveshaft the first time, so another GM one was put in by Stage 1 who told me that was the best replacement.

I'm going to check my altenator first, then I'll go to check the oil. I'm currently running an AC Delco oil filter, I double checked on the tightness the other day and there are also no oil stains or usnuauly drips from the motor. I power washed the area when I had the motor out last.

I think we've found our problem

[ar0ck]

Well I tested the car today, oil was clean, no metal shavings or anything abnormal. I tried to connect a volt meter to it but wasn't sure if I should have it set to AC or DC. Also where should I be touching the leads on the volt-meter? I have the one red wire coming from the battery, and then the wire harness for the gauges. Also I let the car warm up and everything seemed normal... Its strange, maybe something heated up and malfunctioned and it was a freak accident. I won't test it but tomorow I'm having a buddy check the oil pressure since I have no clue what to do.

[ar0ck]

Its definitely the alt. I had someone come over and take a look at it. It was humming and all the lights were pulsing with the cam.

I'm going to try and find a higher amperage alternator from a local store.

[bobb1589]

shuold have volt meter set to DC all car is DC

[Tru2Chevy]

You should still go pick up a decent electric oil pressure gauge and run it into the car. They are more expensive then a mechanical one, but with an electric you won't have to worry about running oil into the passenger compartment of your car.

- Justin

[ar0ck]

Yeah the car doesn't run anymore. After it warms up the oil pressure drops, the car won't idle I hear a thumping noise again with no power and it dies on me.

I can't win

[NJSPEEDER]

if stage1 did all the work on the bottom end i woudl get it right back over there ASAP.

[enRo]

Demod the car, take what you want off it, and drive it into a brick wall. Collect insurance, get an LSx :lol:

[Teds89IROC]

I agree with Tim, get it back to stage 1

[NJLT1SS]

I think he supplied a stock shortblock. That being the case, I wouldnt bother trying to get anything from Stage 1. Stock shortblock + heads + cam = kaboom. Find another block, and build yourself at minimum, a budget 355. Something like this: stock crank, Comp Star rods, and SRP pistons. Do not reuse the stock PM rods, they are junk. Have your heads and cam installed on on the 355, and you will be set.