Low oil pressure in ZL-1

**Alss** · #1 03-11-2009, 02:52 AM

I am in the middle of taking the ZL-1 out of the Malibu. Really PO'd but at least its not blown up. OIl pressure is very low..29 lbs cold and less than 5 hot...not good!!..been that way since we started it up fresh machinist will take care of it whatever it is....were thinking bad oil pump or pick up as the oil is foaming..or maybe a missing gally plug..oil filter is good also..first time this has happened with a new motor..dont know who is worse..me or the machinist..he keeps calling to check on my progress..we shall see what the problem is..thanks for hearing my vent

Albert

**njsteve** · #2 03-11-2009, 03:15 AM

Better to catch it now when it's still fresh versus later when the low pressure has taken its toll.

Was the pickup welded to the pump?

**Rixls6** · #3 03-11-2009, 03:20 AM

Good thing your machinist is that concerned about it.
Hope it turns out to be a simple fix.

jeff morocco · #4 03-11-2009, 03:21 AM

that happened to me too with one of the motors for the 57. only ran it for a few hours and took it to the track. staged the car and noticed i had only 5 lbs of pressure....spun a bearing some how. at least it was caught before anything too bad happened....i feel your misery !!

**427king** · #5 03-11-2009, 03:26 AM

The pickup is most likely not your problem ,but add 3 Qts of oil above full ,if it doesnt change the pressure its not the pickup. Drain oil and stick a wire in the pan to feel around for the pickup. Foaming is most likely due to moisture [water] or contaminate in oil. And of course check the gauge to see if its working right.

**Alss** · #6 03-11-2009, 03:43 AM

[ QUOTE ]
The pickup is most likely not your problem ,but add 3 Qts of oil above full ,if it doesnt change the pressure its not the pickup. Drain oil and stick a wire in the pan to feel around for the pickup. Foaming is most likely due to moisture [water] or contaminate in oil. And of course check the gauge to see if its working right.

[/ QUOTE ]

This motor has had poor pressure since I started it for the first time..I have changed the filter..added extra oil, checked both the eletic factory gauge and the mechanical guage with no changes.pipck up is welded...motor is quiet and has oil on the top end..just looses most of its presure when hot..crank is new..rods are new..machinist is very qualified..we have recently fired 4 of his motors..2 L-78's 1 454 and my 427..the other three are perfect 60 psi cold 30-60 hot with good response to the throttle..it has to be the pump is no good..cant be anything else??

**427king** · #7 03-11-2009, 03:56 AM

Have you replaced the pressure relief valve?

**Alss** · #8 03-11-2009, 04:10 AM

[ QUOTE ]
Have you replaced the pressure relief valve?

[/ QUOTE ]

this block does not use one.....bowtie design thanks for the good ideas..keep them coming..gotta be a simple answer

**427king** · #9 03-11-2009, 04:19 AM

Pull motor,drop pan,change pump.Dyno. Lastly, dont assume you cant have crud [or a blocked screen] in a brand new motor. Have seen many silicone/gasket material blocked motors too.

**69SSZL1** · #10 03-11-2009, 05:05 AM

Is this a new ZL-1 Chevy block 053 casting? it does use a relief valve under the oil filter. Make sure is was installed and staked in the correct hole as there are 2 holes it fits in. If not there, could be your problem.

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