No Oil Pressure

[slakjaw]

HI,

In the rebuild book it says to crank the motor over to build oil pressure. I have been cranking and no pressure is building. Please confirm that I have everything correct. The motor is a 7R case with pretty much every thing from original 2.2 in it. I installed everything just how it was on my original 2.2. The oil pressure sender is towards the front of the car and the temp sender is on the rear where the cam oil lines connect. Is that OK to do with this case? How long should one have to crank before seeing oil pressure? Any other ideas? Please.

I know that oil is circulating because pulled the temp sender and oil flowed out.


Thanks,
Kyle

[Jim Sims]

Is the sender hooked up correctly and do you know if it worked previously?

[Bob Spindel]

I've never been able to register any oilk pressure when cranking. (Most 911's don't register anything when ayt idle!) From what you say, I think you're ok. Fire it up!

[Doug Zielke]

I wonder if there really *is* somthing wrong?
After about 3 sessions of 10 second cranking, my 3.0 showed movement of the oil pressure gauge.
Also, the idiot light should go out after just a few cranks.

[Alan Cottrill]

did you put the seals on the oil pump?

[Porsche_monkey]

I couldn't develop pressure by cranking on my first start-up. I cracked a fitting loose on the chain tensioner to make sure I had oil flowing (I did) then I fired it up. No problem.

[cstreit]

You might try and make it easier for the engine to turn over by removing spark plugs...

I have always been able to see oil-pressure on the guage after 20-25 seconds total of cranking.

[ChrisBennet]

I won't swear to it but I don't remember is taking that long to get oil pressure when I've cranked over a newly assembled motor. I crank it over for a little while until the oil pressure needle starts to wiggle.

I'll probably catch s**t for saying this but on the advice of mechanic friend of mine (who's done a lot of 911 motors in 20+ years of business) I've always put some lithium grease in the pump. Something about helping it make suction when first starting I think. Now of course I know the pump is just filled with oil anyway but if my friend told me to put garlic around my neck when rebuilding a motor, I'd do that too.
-Chris

[Rot 911]

He also posted this on the tech board. Turns out he had a stuck gauge.

[slakjaw]

Yeah I Grounded the wire a few times to get the needle to move up and down. then i cranked it again and the needle went to 20 PSI.

[Wayne 962]

Originally posted by Bob Spindel
I've never been able to register any oilk pressure when cranking. (Most 911's don't register anything when ayt idle!) From what you say, I think you're ok. Fire it up!

Sorry Bob, that's not good advice. This is the time when you want to check to make sure that you don't destroy $5000 worth of parts because there's no oil pressure.

It's different when you crank the engine to start it, from when you crank it after a rebuild. It will take 20-30 seconds to build oil pressure when cranking. The no-oil pressure at idle that you are referring to only occurs when the car is warm, not when it's cold. You should be able to get plenty of oil pressure under cranking when the engine is cold.

Check the pressure sender. If you can reach it, remove it and then have someone crank the engine. If oil spurts out, then you're okay, and your sender is either defective or not hooked up properly.

Don't just fire it up - that could be a recipe for disaster...

-Wayne

[Wayne 962]

Originally posted by ChrisBennet
I won't swear to it but I don't remember is taking that long to get oil pressure when I've cranked over a newly assembled motor. I crank it over for a little while until the oil pressure needle starts to wiggle.

I'll probably catch s**t for saying this but on the advice of mechanic friend of mine (who's done a lot of 911 motors in 20+ years of business) I've always put some lithium grease in the pump. Something about helping it make suction when first starting I think. Now of course I know the pump is just filled with oil anyway but if my friend told me to put garlic around my neck when rebuilding a motor, I'd do that too.
-Chris

The grease won't hurt anything, but as you mentioned previously, when you fill the tank, the oil goes right into the pump...

-Wayne