jimjomack

Follow up on my post on 9/7/03. I checked hose routing and they are OK. I called Moroso and they claim that the oil pump is pumping all the oil up to the top and that I am running out of oil at the pick up tube. With an 8 quart sump on the 502 Gen 6 engines I can't see that happening. I called my engine builder and he said to add 2 more quarts to the engine and try that. All oil plugs were installed correctly including the ones under crab pan. I notice there are 2 sending units at the back of the block. The one larger can above the oil adapter is the actual oil sending unit. Does any one know what the unit is that is mounted at top edge of block just before the bell housing. If I remove this wire the engine alarms do not go off. When the oil pressure reaches 0 psi after 15 min of running at about 3000 rpm the alarms do go off, so I know they work but the engines still do not rap or knock, even if I still run them hard with oil pressure. Could something be happening where the bearings and lifters are getting oil but the sending unit is not? I would like to try and know the real problem before I have to pull the engines and install the stock chevy oil pumps. Thanks for any help.

blue thunder

That second "sender" is a low pressure switch. Basically a set of contacts that close at 3psi or so. Not sure the exact number. When they close the alarm sounds. Sounds like that is working properly. To conclusively find out if you have a bearing problem, cut open the oil filter and examine between the pleats for bearing material. Make sure you chisel it open or some other non-shaving producing method.

BT

OhioRiverCigarett

Is it possible to have good oil presure in the engine and the port above the oil filter to not indicate it (Sending unit or mechanical gauge).

articfriends

iTrader: (1)

Wishful thinking 99% of the time. I had a sending unit go bad before,a tiny piece of crud plugged the hole and gauge hit zero and stayed there BUT alarm didn't go off. I pulled sending unit on the water,put my finger over the oil port and had wife crank motor over,oil blasted by my finger from just cranking.I screwed sending unit back in,still showed zero but I was confident it must be plugged,drove boat all weekend with gauge at zero and replaced sending unit. In your case you have oil pressure cold but not hot,a sure sign that once the oil thins out its going somwhere from excessive clearence or damaged components. The alarm sender AND gauge sender are not going to both quit when hot but work cold,you have bigger issues,Smitty