tt9714

Although this may a little premature (my car is still in pieces), I'm looking for feedback on the procedure to follow when restarting my engine ('86 951) for the first time after major mechanical work. (the block, head, and cam tower were untouched)

On the bottom end, I have replaced the rod bearings, oil pan baffle, and oil pan seal. On the top side, I have taken out & reinstalled my turbo. I have also replaced my clutch master, clutch slave, and brake master cylinders.

My initial thoughts:
1) flush the fuel lines before reconnecting to fuel rail by manually turning on the fuel pump at fuse panel; collect some fuel in waste container
2) pressurize fuel system by manually turning on fuel pump at fuse panel (fuel lines connected)
3) refill coolant
4) refill engine oil
5) build oil pressure before starting. Temporarily disconnect the fuel pump fuse.
6) after observing sufficient oil pressure on dash gauge, reconnect ignition and start engine
7) bleed coolant system after starting engine
8) deal with the hydraulics (brake & clutch) separately after engine is running properly

Thoughts and comments please...

Luke

how do you build oil pressure without running? <img src="confused.gif" border="0">

Ahmet

Turn engine over without spark and or fuel (pull DME relay out).
Ahmet

Perry 951

You can't. Cranking does not spin the pump fast enough to draw the oil into it.

Use a good amount of assembly lube. That is about all you can do.

afahrlan

The oil pressure sits near 0 w/the red warning light for the first 1 to 2 seconds after starting my 951 when cold, then shoots to 5. I assume this is normal? Topped off oil and no leaks etc.

Andrew

Mike B

Stan Kolen posted this on the Pelican Board

[quote] Make shure you spin the engine with the starter and the plugs out till you get an oil pressure indication, B 4 your first start.
If you dont get a pressure indication the only way to prime the oil pump is to remove the oil filter and pour oil into the filter cavity and then turn by hand the crank pulley in reverse, this will put the oil into the pump galley you will need to pour about 6 oz of oil into the system and turn the crank backwards, This should put a good prime into your system, reinstall the oil filter and crank with the starter till you get a solid oil pressure indication on your gauge. <hr></blockquote>

Seems like sound advice...<a href="http://www.pelicanparts.com/cgi-bin/vb/showthread.php?s=899893395f0c31c8fda40738cc3a5344&threadid=61986" target="_blank">Here</a> is the whole thread if you're interested...

Ahmet

[quote]Originally posted by perry951:
<strong>You can't. Cranking does not spin the pump fast enough to draw the oil into it.

Use a good amount of assembly lube. That is about all you can do.</strong><hr></blockquote>

Both of my 944s have pressure (according to factory gauge) after the engine turns over 2-5 times depending on the viscosity of the oil/outside temp. If the oil pump has been apart priming it as Stan suggests is the only way to get pressure. My original post was a reply to Luke. In tt9714's case this should not be necessary, it wasn't when I did the bottom end on my 944.
Ahmet

Perry 951

If you read the shop manuals, it tells you the way to prime it. (Adding oil in place of the filter.. as stated above.) Taking out the plugs and crank up the starter is not what I would do, but everyone has their own ways.

You cannot spin the pump fast enough during cranking to overcome dry cavitation. You will see slight pressure on normal startup becuse there is oil in the pump and main feed galley. It is minimal, and I would say the gauge is bouncing from the current draw of the starter. However, on a fresh rebuild, there is no oil in the pump itself. 9 out of 10 times it would begin to draw oil into it within seconds, but there is a possibility of cavitation and no oil for an extended period.

Bottom line, if you have good assembly lube, and used a decent amount of it, you have no worries. If you have not removed the oil pump, it should start the same as changing the oil. Just a moment of no pressure. (actually, there most likely is pressure and oil flow in the crank, but the oil has not reached the sensor yet.)

Ahmet

Perry, it's my understanding that this specific car in question does NOT need any special procedure...

I don't know if our pumps are different or what but my 84 has the oil light go off around the 2nd crank (this is when the gauge also registers slightly above .5bar), and around the 3rd or 4th crank the gauge shoots to 5 and stays there if I keep cranking.

Anyway, you're probably right priming is a good idea, but I don't think it's necessary if you've still got oil in the pump/oil filter etc. and I think this car in question does.
Ahmet

rplencne

After a complete rebuild of our early '85 last summer, we primed the engine by removing the plugs and cranking it over (with the fuel pump disabled) for about 5 seconds. With the plugs removed, the engine is allow to spin over a lot faster. That was enough to get the gauge to start showing some pressure (&gt;1 bar). We did have the oil pump apart during the rebuild, but we used assemably lube in it to help draw the oil up during the priming. Just make sure the spark plug area is clean so you don't draw any junk in while cranking.

-Bob P.