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Oil Pressure= 0PSI

Posted: Sat Jan 03, 2009 12:40 am
by timothy_nd28
Hello all,

I had to tear into my 94 SC bonneville's engine due to a failed broken hub on a harmonic balancer which in turned ruined the crankshaft key. I had the timing chain cover off to obtain full access to the crankshaft key. I replaced the timing chain and gears for the hell of it. After reassembling the engine I changed the oil and added 5 quarts of synthetic plus the new filter. I started the engine, ran it for about 5 secs, turned off after seeing no oil pressure. I reinstalled the old oil pressure sensor and restarted the car. Same results. I'm starting to second guess myself on the procedure of the oil pressure relief spring and plunger. The plunger goes inside the bore first, followed by the spring, then the outter plate with the 4 bolts? This is the way I have it currently. The plunger did get hung up alittle when it was pushed inside it's bore. I was too lazy to clean out properly this hole, and I think some dirt is holding the plunger from moving. I'm having a problem getting this plunger out. I also removed the oil filter, there is no trace of oil inside this at all, thus confirming the 0 oil psi. The diagram on All Data shows 4bolted plate, plunger then spring,,is this right? Any advice on how to retrieve this plunger from the hole?

Thanks,

Re: Oil Pressure= 0PSI

Posted: Sat Jan 03, 2009 1:07 am
by willwren
Your assembly sounds correct for me, and you have a stuck plunger.

The best I can suggest is removing it with compressed air. If it's bound up in there, I don't think a magnet is going to help you.

Re: Oil Pressure= 0PSI

Posted: Sat Jan 03, 2009 1:36 am
by timothy_nd28
Image

Here's the picture off All Data

Re: Oil Pressure= 0PSI

Posted: Sat Jan 03, 2009 2:12 am
by willwren
That is correct.

Re: Oil Pressure= 0PSI

Posted: Sat Jan 03, 2009 9:49 am
by Mechanical Mike
Shouldn't the spring go into the block first, followed by the plunger?

Re: Oil Pressure= 0PSI

Posted: Sat Jan 03, 2009 12:28 pm
by agrazela
Mechanical Mike wrote:Shouldn't the spring go into the block first, followed by the plunger?
x2.

I believe this is your problem.

Re: Oil Pressure= 0PSI

Posted: Sat Jan 03, 2009 12:32 pm
by willwren
Maybe I read his post wrong last night. But then again, He posted the pic. Which way WAS it installed?

Re: Oil Pressure= 0PSI

Posted: Sat Jan 03, 2009 12:35 pm
by myfirstbonnie
timothy_nd28 wrote: The plunger goes inside the bore first, followed by the spring, then the outter plate with the 4 bolts?
I think he put it in wrong also. His explanation states he put the plunger into the timing cover and then the spring topped with the oil filter adapter.

Re: Oil Pressure= 0PSI

Posted: Sat Jan 03, 2009 12:43 pm
by timothy_nd28
Hail to the bonneville god up in the heavens, my prayer has been answered! :hail: I got that stuck plunger out of the hole!!! I'm off to the local autoparts store to pick up a new gasket, actually I'll get 2 just in case I have to pull it back apart to configure the spring plunger assy a different way. Thank you guys for all your help!

Re: Oil Pressure= 0PSI

Posted: Sat Jan 03, 2009 12:46 pm
by myfirstbonnie
When you re-assemble it, put the spring into the hole, the plunger on top of the spring and then the gasket and plate with the 4 bolts.

The spring is the force applied to the plunger which presses against a hole. Therefore the spring sets the oil pressure by how much it "bleeds" off. Basically you was dumping all your oil pressure back to the pan.

Re: Oil Pressure= 0PSI

Posted: Sat Jan 03, 2009 2:09 pm
by willwren
To clarify, the spring goes into the hole on the timing chain cover end, and INTO the plunger on the oil filter adapter end.

Re: Oil Pressure= 0PSI

Posted: Sat Jan 03, 2009 11:11 pm
by timothy_nd28
I re-installed per the way you guys said, and now the car has beautiful 40 psi of oil. Thanks all,,
During the first 10 mins of idle, I heard some clunking noise from the SC, which is a new noise. I went to rev up the engine, and noticed the boost gauge not able to achieve anything higher than 0psi of boost. I take it that the SC has failed. This is the first time this engine ran in over 6 months. I'm not sure what it is about this car, but it's in love with the number 0

Re: Oil Pressure= 0PSI

Posted: Sat Jan 03, 2009 11:31 pm
by Mechanical Mike
Since it sat for 6 months the first thing I would check is if the boost bypass valve moves freely the full 90 degrees. If not then try some PB Blaster on it.

The PCM might be pulling boost due to the noisy supercharger. The noise is probably from the coupler, not actually the supercharger itself.

Re: Oil Pressure= 0PSI

Posted: Sun Jan 04, 2009 1:06 am
by willwren
The supercharger cannot 'fail'. Period. Even if the coupler breaks and you get a horrible clattering noise, the supercharger itself cannot fail unless it self-destructs under the hood.

Follow the advice above.

More info available on my supercharger page:

www.3800supercharger.net