WEIRD oil pressure issue on barely broken in Z06

**calee4nyaboy** · 09-17-2007, 01:00 PM

Hi All, I have an ’02 Z06 with only 8,000 miles on it. It is doing the weirdest thing. If the car is started from cold, the oil pressure gauges reads 45 PSI which is right about where its supposed to be at idle (my ’01 also reads that). The problem is that after about 1 minute (I timed it) the pressure just drops to zero in a matter of probably 4 to 5 seconds…the needle just falls. On its way down, the “low oil pressure” warning comes up on the digital display along with the “ding, ding” noise.

I turned the car off because the oil pressure was at zero. Not knowing if it was a fluke of some sort, I decided to carefully start the car a second time to see if it would go back up to 45 PSI for a minute again and then fall. Well, it didn’t. The needle immediately goes to nothing showing no pressure and the low pressure warning came on again. Keep in mind that the car had only been started for a minute previously and it had been sitting over night so it was cold. In other words, the oil couldn’t have warmed up THAT much in only a minute. And the needle falls fairly quickly, NOT gradually as, for example, if it were falling with rising oil temperature as the car warmed up.

I waited for it to be cold again and tried again with the exact same results:

- Start from cold, oil pressure at 45 PSI (idling).
- One minute later, falls to zero PSI.
- Revving does NOT help bring up pressure even 1 PSI.
- Turned off car.
- Immediately restart the car, zero oil pressure right off the bat.

This can be reproduced over and over it seems. What in the world is this? Right when the needle fell to zero, I carefully revved the engine for a second to see if the needle would jump up and it did not. The oil in the car was changed only a couple 100 miles ago with the Series 2000 Amsoil 0w-30 oil and Amsoil filter. The car has run fine until now and at no time, now or before, do I hear any odd engine noises that might be associated with low oil level. It was changed so recently that the oil is so clear it’s even hard to read on the stick but it is up to capacity so it’s not a low oil level issue. I want to get one of those pressure testing tools that goes where the oil filter goes but I don’t know who sells them. That tool would eliminate a bad oil filter (although highly unlikely) and the sending unit (although I’ve heard when sending units go out, they typically read way to high, rather than low)

I CAN NOT believe this car is doing this. It’s barely broken in. Any suggestions would be welcomed. I am pretty mechanically inclined and could change either the sending unit or the pump if necessary, but lets face it, it’s not both of them so I don’t want to tackle the wrong issue. Heck I don’t even know why either of them would have failed this early on. This really kinda irritates me that an 8,000 mile Z06 left me stranded having to call a wrecker last night.

Thanks guys!
John

**calee4nyaboy** · 09-20-2007, 11:23 AM

Gee, lets not have everybody all reply at once...lol

John

**Danger731** · 09-20-2007, 12:06 PM

Change out the fluid with 10w30 and see if it fixes the problem. If it does then it was the oil.
Who did the oil change ? johnny snot nose at jiffy lube while he was thinkin about his gf ?

**calee4nyaboy** · 09-20-2007, 12:50 PM

It's brand new Amsoil oil. I'm certain it's not the oil. I did the oil change as with all the work on my car.

**Danger731** · 09-21-2007, 12:21 AM

Stuck relief valve in the oil pump.

**bills98ta** · 09-21-2007, 03:33 AM

Ya, I'd change it again too, and use a fram filter, or a different filter... That doesn't sound good at all... Don't drive it until you get this resolved... Could be the oil pump failing, but you might get lucky.

**z28punk** · 09-24-2007, 06:48 PM

bring it to the dealership if it doesnt get fixed from the oil change. u get it fixed right away to avoid more damage.

**Hi-Po** · 09-30-2007, 05:43 PM

Originally Posted by bills98ta

Ya, I'd change it again too, and use a fram filter, or a different filter... That doesn't sound good at all... Don't drive it until you get this resolved... Could be the oil pump failing, but you might get lucky.

Fram filter will make your engine cry.

**Bugaboo** · 10-03-2007, 01:50 PM

pressure sender is a known problem at times..........

**z28punk** · 10-03-2007, 09:11 PM

its not a very common problem, but the senders are the culprit most of the time in these cases.

**calee4nyaboy** · 10-05-2007, 10:47 PM

Okay, the verdict is in: I finally got the KD Tools mechanical oil pressure test kit and attached it to the where oil filter goes. I turned the car on and after 30 seconds or so, the dash started screaming low oil pressure. I looked down at the mechanical gauge and it read 45 PSI. I let the car idle for 5 minutes looking at both the dash and the mechanical gauge and the mechanical gauge never came off 45 PSI but the dash did fluctuate from 0-10 PSI; the needle just kinda floated around aimlessly between 0 and 10 PSI.

I doubt there is a problem with the instrument cluster so it’s something under the hood. So my question is: on the back of the block where the parts are attached for the oil pressure, what all parts am I looking for? Is there an oil pressure switch AND a sender unit or are these two things built in together making it just one part or?

Thanks,
John

**bills98ta** · 10-06-2007, 02:56 AM

It's the part ! That is your sending unit. Glad that's all it was !!!

**vader97** · 10-06-2007, 12:33 PM

oil pressure sending unit(sensor) is behind the intake manifold. When you change it out, reply to the post and let us know how it all worked out for ya!

***Ed Blown Vert*** · 10-06-2007, 12:55 PM

Originally Posted by calee4nyaboy

Okay, the verdict is in: I finally got the KD Tools mechanical oil pressure test kit and attached it to the where oil filter goes. I turned the car on and after 30 seconds or so, the dash started screaming low oil pressure. I looked down at the mechanical gauge and it read 45 PSI. I let the car idle for 5 minutes looking at both the dash and the mechanical gauge and the mechanical gauge never came off 45 PSI but the dash did fluctuate from 0-10 PSI; the needle just kinda floated around aimlessly between 0 and 10 PSI.

I doubt there is a problem with the instrument cluster so it’s something under the hood. So my question is: on the back of the block where the parts are attached for the oil pressure, what all parts am I looking for? Is there an oil pressure switch AND a sender unit or are these two things built in together making it just one part or?

Thanks,
John

Where did you get that tool?

**calee4nyaboy** · 10-06-2007, 07:35 PM

It's a KD Tools Oil Pressure Test Kit. Model number 3289. Google it and all kinds of places online sell it. It's neat cuz it's universal, it'll fit on just about any car made.