mrmikelt1

i have a 1995 z28 with a 6 month old 383 stroker. the other day i started it up and ran for about 5 min. after fixing a bad injector wire, let it sit for about 30 min. came back started it , some of the valves were rapping ,went to shut it off and noticed zero oil pressure, just like that. pulled the valve covers to see if a push rod popped out and let a lifter come up to bypass oil pressure, everythimg looks good up top. went below dropped the fresh oil change i did last week and used a video scope to look in pan at oil pump pickup and it appears attatched still. next step drop the pan?? any ideas would be greatly appreciated!

rclearyiii

Just a long shot..but did you try changing the oil filter to remedy the situation? Short of that I guess it would have to be the oil drive shaft to give zero oil pressure.

Dave1980

X2 the oil gear drive is where I would look next.

94Z28LS1toLT1

happened to me when i was driving i have my 94 Z28 i ended up screwing up my engine bad!!!!! id check the oil drive

JAKEJR

On an L98, during an oil and filter change, I once got ZERO pressure due to a bad oil filter. Changing filters cured that.

On another occasion, on my 96 LT1, I had the gear fail on the oil pump stub shaft.

So it could be either or something else entirely. I'd swap the filter first - change brands too.

Jake

West Point ROCKS! Natin's TOP COLLEGE per Forbes Magazine!

Airbornec507

I hope you've checked the oil sending unit on the back of the block behind the intake. If it's bad or has a leak you will get a zero reading as well.

Dave1980

The LT1 has a bypass if the oil filter clogs or does not work. (unless you leak all oil out)

JAKEJR

That's the amazing thing about it; the L98 engines do too.

Jake

West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!

mrmikelt1

oil pump drive gear was bad . couldnt find one aftermarket though, i ended up going to the dealership.

shoebox

Just curious if you are running an HV pump. If so, I guess you need to be prepared to check/replace the oil pump drive around every 6 months.

JAKEJR

ABSOLUTELY! You can take that to the bank.

I've been down that road four different times on three completely different engines over the past five or so years. Three times on L98s; the first one was a 355 TPI, twice on a Mini-Rammed 415 and once on my 388 LT1. I even tried a different distributor and new gear on the 415.

Different camshafts in three of the four instances too. The 355 had a ZZ9 and on the 415 the first cam I installed was the same ZZ9 and the second cam was a custom ground CompCams HR. The CompCams grind even had a new GM melonized gear. The 388 has a CompCams XFI.

Each time a gear failed I installed a brand new one; never a used gear.

Here's the play by play:

I rebuilt a stock 86 350 (became a 355) and installed a new GM gear. After several months, the oil pressure began to flucuate, so I pulled the distributor and saw excessive gear wear, so I bought a new one, another GM gear. I sold the engine a few months later.

I replaced it with a freshly rebuilt 415 running a ZZ9 and used a new gear. Several months later that gear died. I then moved to a custom ground Compcam and installed a new gear, again; this one was a GM melonized gear. Several months later engine shut off as I was driving down the road. Pulling the distributor showed the gear's teeth were all but non-existent. I replaced the gear and all was well again.

Even at this point I still hadn't made the connection.

I sold the 86 Vette with the 415 and bought a stock 96 LT1. A while later I decided to build a stroker for the car, but, at that time, I still didn't suspect it was the HV oil pump causing my problems, so I bought a new HV pump, a Moroso with the anti-cavitation slots milled in it.

I installed a new GM gear on the stub shaft, but, sure enough, after several months same thing happened. I pulled away from the house and as I looked down at my gauges and saw ZERO oil pressure. Pulling the intake and checking the gear showed half the teeth were gone.

I then put on my thinking cap and zeroed in on the oil pump. I dropped the HV pump and replaced it with a standard volume Moroso pump and all was well again. That was in 2007 and I haven't had a gear problem since.

Another point, I lubed each new gear well, before installation, even using an old tooth brush to be sure to get the moly lube into all the crevices.

In every instance of gear failure, the common denominator was the HV oil pump. Of course, should you still desire to run one, be my guest.

Just my tale of woe.

Jake

West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!

95Blackhawk

I now thank god I never found the need to go with a HV pump. I always have good pressure even at 6K+