As the title says - I'm curious.

The engine, after itw as rebuilt, was started and had 20psi oil pressure cold, then made its way down to 10-15psi as it warmed up. It was missing a freeze plug at the front of the engine, so there was no oil going to the valvetrain.

But what I'm more concerned about is the bottom end. I've heard that ~10psi per every 1k rpm is ok, so I'm hoping since the motor never went past 1500rpm, the bearings are still good. The freeze plug is now in place and I get strong oil pressure at idle, at least 50psi.

Advice?

 

how long was it run? the longer it ran the more chance damage occured, but provided oil still flowed properly throughout the bottom end, meaning that the missing plug didn't cause oil to skimp on a few bearings, your bottom end I would think would probably be ok, give us a little more info so we can help more, like, which plug was missing (was it truly a FREEZE plug, like, to plug coolant passages in the block), how long was it run that way, anything else that you can think of that might be a little helpful.

Hope this helps a bit, maybe some of the more knowledgable LT1 specific guys will jump in on this one.

 

thanks for the quick reply, jbird.

lets see, the engine was run for about 5 minutes. It ran pretty smoothly, albeit clacking lifters (no oil pumping them up). It only idled, and no load was put on it.

The missing freeze plug was at the front of the engine - I didn't get the exact details, as it was a shop that did my rebuild. After they figured out the cause of the low oil psi, they told me it was a cracked freeze plug - but my friend's father (who is a very very longtime experienced mechanic), says that its more likely that they just forgot to put in the freeze plug, as when the block comes back from the machine shop, there are no plugs installed in the front.

Anyway, the oil pressure started at 20psi, and as soon as it got into the top of the red (around 10-12psi), we shut it off. Hopefully this sheds more light on the situation - right now I'm debating on whether to pick up the car myself, or to pick it up with a tow truck to have it towed to the dealer for inspection of metal shavings in the oil filter and etc.

 

im sure he means oil passage pipe plug....
I'd imagine your bottom end is ok. and the fact that you have 50 PSI now kind of confirms that. if you had put alot of wear on those bearings you would have less oil pressure due to the increased oil clearances.

 

great, thanks for the advice Dave. Now I can sleep a little bit better tonight.

can anyone else confirm this? I'm pretty sure the bearings are ok, but I just want to make absolute sure before pulling my car out of the shop.

 

LT1 specs say 6psi at idle is the minimum so you should be ok

 

I would think that the bearings will be fine. The good news is that you didn't rev the engine up or take the car for a drive while the engine had a problem.

The story about the cracked freeze plug sounds like a load of bull **** to me though...

 

great to hear guys, thank you for all the advice!

Yeah, the cracked freeze plug? It does sound like BS, my friend's father has worked in 16 dealerships with a 3.5 year trade school training over the past 30 years, and he's damn sure they just forgot to put the plug in - because when the engine comes back from the machine shop, the plugs are out and you've got to put them in yourself, at least at the front of the engine.

well either way, as long as the bottom end is fine, ihave no qualms. hopefully I will be driving home in my baby tomorrow, it's been a long time!

Thanks all!

 

You know what?

Spend the 30 or 40 bucks and have the oil analyzed.

If nothing else, it'll give you peace of mind.