Problems with oil pressure 512tr, need help

Do not start the engine until you found the problem. Your engine may get damaged if no oil is lubricating the bearings etc, if you start it. Take out the fuel pump fuses so the engine doesn't start. Have you tried Eurospares, Ricambi for new parts ?

 

In my experience, those scratches are not bad enough to create a zero (or close to) pressure condition. Check the pressure with a known good mechanical pressure gauge first (at the pressure sender location). Don't rev it, just idle it. If pressure drops below roughly 10psi/1000 rpm STOP.

Remember, I believe you have a dry sump system which means you have a multiple stage pump for scavenging (sucking) the oil from the crankcase up to a holding tank which then feeds the pressure pump. There's probably an oil cooler in the circuit as well. If there's a restriction anywhere along this circuit you'll see low pressure. Also, make sure the holding tank has enough oil to start with!

Since you mentioned the engine as being just rebuilt it could be an assembly issue as well. Maybe a bearing shell was left out, an oil galley plug not installed, a head gasket installed incorrectly, there are many possibilities but I'm not that familiar with the oiling circuit on that engine.

 

The 512TR WSM has some very good drawings with all the internal dimensional specs for the oil pumps (like, for the high pressure pump, the radial clearance from the gear ODs to the housing IDs should be .027~.048 mm, and the nominal clearances and wear limit for the bearing areas) -- unless you are outside those values, I wouldn't think a new housing would be needed (nor make any difference). And, forgive me if this seems overly-simplistic (compared to already disassembling the high pressure pump ), but did you try using a different oil filter (in case yours has collapsed internally)? Unless the housing and/or gears have some obvious dimensional problem, I'd be more suspicious of the pressure relief valve not working correctly, being stuck open, etc..

 

Steve's post is excellent. I don't know the 512's but if it is a dry sump, you can check the oil level in the tank under revs. If scavenge pump is not working proper or screen is clogged, low OP can happen (not delivering oil to the tank at the proper rate)

 

Any update?

 

How's the bypass spring and valve in the pump?

 

Check all of the oil lines, have seen on a 348 the main feed from the oil tank to sump collapsing internally causing restriction and loss of oil flow to the pump, resulting in low/no oil pressure.

 

Check the white molex connector on the left rear of the engine bay for corrosion, it's not water proof, the gauge may or may not show a reading, "Before you blame the oil pump" and also check the oil sender switch on the top of the oil filter housing.

Btw what engine oil weight are you using, remember has to be "synthetic" 10w-50 minimum.

TR do not like light weight oils!!!