puder

the marina that worked on my boat last summer told me they "topped off" my oil before I picked it up. My oil dipstick rusted and the tube cracked so it had to be removed and capped temporarily. They said they "topped it off" just to make sure i would be fine to run for a little bit to test/tune the new engine setup. Well i just started working on her tonigh and when I pulled off all the oil lines and such not very much oil came out. O si went and opened the dump holes on the oil pan. In all maybe 1 1/2 quarts came out.

Unless i had special oil that evaporated since september i am thinking they never "topped it off"

would the super low oil (maybe 2-3 quarts) account for the low oil PSI? It occured all of a sudden. Prior to all the work i did last season (heads cleaned up, added a little blower)the pressure was fine, afterwards it was low.

Andree

Hi Puder,
first of all did you checked the pressure with a mechanical gauge? maybe you have only a gauge problem. If not just let the engine run with correct oil and new filter if the filter is closed you have no pressure too.Test again. No pressure than change bearings and pump and in 95% thats it. Usually the front or the rear bearing break down first. If you want to eleminate another potenial failure change by pass valve for the oil filter maybe the spring in it was old or broken. I have done the work last year on my 1988 454 and in my case it was a bearing I changed all and the pump and it was fine.
Andrée

28Eliminator

puder, That will definitely cause the low oil pressure.
It probably had enough oil to show good pressure when you got it back from the marina. How long did you run it on low oil pressure? If you don't have a lot of time on it, then you may be ok with just changing oil and filter. I would try that and see if the oil pressure comes back up. If it doesn't then you will have to do what Andree said; however, you won't know what parts you need until you get it apart. If you need to change a bearing then you will probably need to polish the crank journal at a minimum, which requires you to remove the crank. If I was going to pull it apart, I would go all the way and rering it also, unless you did that last year also. I would only want to do the job once and know that it wasn't going to break down in the middle of summer.
Good Luck and let us know what you find out!

WETTE VETTE

The mechanical guage is a good idea. You could also cut open the oil filter and see if it is full of metal. If it is you probably have bearing problems on the mains. If you are using a high volume oil pump and the clearances are near what Chevy specs, you'll want no less than 5 qts in the pan. With a low volume pump and below 6500 rpm you need no less than 4 qts in the pan. There is no real reason to run your oil this low though. Just another useless piece of info that may come in handy some day. Good luck!!

puder

i did put i a mechanical guage. AT idle i was around 20psi. Which was ok. But as rpm increased it was steady for a little bit and theyn slowly dropped ouf down to about 12-15psi. I didn;t run it very long and kept the rpms down. I figured at idle and ow rpms i was ok with that pressure but at higher RPM it wasn;t enough.

I don;t think it is a problem with the bearnign simply becaus one day it was fien and then next it was low. When it came back from being worked on it was low. I woudl thin kif my bearings were shot it would gradually get worse and worse. Am I right in that presumption?

FYI all eth work that was done last year was done with teh negien in teh boat. I pulled it this winter and now have it in my garage. I am re-rigging my engine bay (and converting to a bravo)and going over the engine to make sure she is goign to run right this season and doing a paint job on her.

If i start the engene in my garage will it show decent oil PSI at higher rpms without a load? I know the blower won't register and boost without a load on it. BUT iwoudl think teh oil PSI should be fine.

WETTE VETTE

If it is out of the boat I would drop the pan and pull the main caps off and check it out. If they look OK you should be good to go. If you do this get one of those 1 piece pan gaskets, they're pretty simple to put on. I would hate to see you have to pull the engine back out after your first blast across the lake.

puder

LAKE!!!!!!

WE DON'T RUN IN NO STINKIN LAKE!!!!!!!!!

the LI sound is salt and canget pretty snotty some days.

but thank for the info on the one piece gasket. Will do.

Andree

Puder ,
Actually you're right if you had a bearing problem the oil pressure will go down Hour by hour. Exept the bearing cracks but this very seldom. The easiest way and cheap is change the filter thy by pass and oil and test. But i would have a look at the bearings because it really sucks if you have to pull out your motor and the sun is shining. And you can be sure if your motor is back in the boat it will rain.
Good Luck
Andrée

puder

i think while its out i might as well check out the bottom end of it.

Prepare for another rash of questions abotu proper plasitguage use!!!

checkmate981

Puder,
20psi @idle is really not so good.If you got 1 and half quarts out of the pan when you drained it this year chances are you sucked the pan dry last year running it witch is not to good for the bearings.Like everybody else said,Pull the oil pan and pull some main ,rod caps and check some bearings.I hope you make out ok
Dave