Can Not Prime Oil Pressure...

[nissan200sx.dk]

Hi all.

I am finished with my RB30DET build, but i can not prime oil pressure.. I have cranked ALOT! Tryed priming oil in the block different places.. I wont pump oil

Any suggestions on what to do next??

Thank you

[Bliksem]

What and where are you measuring pressure with and what oil pump have you used?...

[nissan200sx.dk]

Std RB25DET pump, as used in my RB25DET engine.. Worked perfect.

I do not measure pressure, i look if oil comes out. Both from turbo feed line, and when that did not work, i took oil filter off and watch that hole. No oil is coming out anywere.

I have tryed putting 0,4 liter oil through the oil feed line to turbo, to try and prime it up, i have tryed to put 0,4 liter oil through the hole were oil filter usually gets oil. The thread in the middle. Mounted a hose to is, and have filled ~0,4 liter in there also. Nothing works to get the pump pumping oil...?

When i built the engine oil pick-up got a new o-ring.

Any ideas what i can try and do?

[unique1]

if you have a remote filter take the adaptor off at the remote end (not the motor end) and pour oil down the one that comes from the pump (its usually labelled "out") and turn the motor backwards a few cranks with a socket and rachet. Then crank the motor foward with the starter motor with the lines still off for a second and it should start pumping out of the "out" hose. Dont let the motor fire though, unplug the CAS before you crank with the starter and you can even remove the plugs so it spins over easier.

The other option is usually abit of vasoline in the oil pump gears before assembly makes life alot easier, but too late for that now.

You just have to get rid of the airlock in the pump gears and get oil into it, hence pouring it down the outlet will feed it into the pump due to gravity and then when you crank it forward it will then start sucking it through the pickup from the sump.

EDIT: sounds like your feeding oil into the motor rather than back into the oil pump, its the outer you need to feed it into to prime the pump!

Edited December 5, 2009 by unique1

[nissan200sx.dk]

CAS is of, injectors are unplugged and no sparkplugs mounted..

I do not have a remote oil filter. :-(

Oil to the filter dont that enter in the middle??? From the pump..

Oil pickup - oil pump - oil filter (in the middle) - out oil filter (all the small holes) - to engine block. <--- is this not the correct way oil goes from sump?

[unique1]

CAS is of, injectors are unplugged and no sparkplugs mounted..

I do not have a remote oil filter. :-(

Oil to the filter dont that enter in the middle??? From the pump..

Oil pickup - oil pump - oil filter (in the middle) - out oil filter (all the small holes) - to engine block. <--- is this not the correct way oil goes from sump?

im 99% sure its the way i said above (oil goes from the pump to the outer through the filter and into the engine through the middle hole), but it is 1am here so i cant check just yet, ill have a look in the morning and post it up as i have a few motors here being built i can check.

Ill let u know as soon as i double check

[nissan200sx.dk]

THANK YOU VERY MUCH!!

This would be really helpfull, as this is VERY anoying no oil pressure thingy.. I want to start the bastard up!

Is there any change of damage after all that cranking and no oil pressure? (It was all well lubed when assembled).. (And no spark plugs, so no compression)

[Adriano]

No, it will be fine

[STATUS]

THANK YOU VERY MUCH!!

This would be really helpfull, as this is VERY anoying no oil pressure thingy.. I want to start the bastard up!

Is there any change of damage after all that cranking and no oil pressure? (It was all well lubed when assembled).. (And no spark plugs, so no compression)

depends on how long you cranked for, it is ppossible to wipe bearings.

[nissan200sx.dk]

wipe bearings??? is my brand new engine perhaps already worn??

cranked for a total of 5 min i think....

Edited December 6, 2009 by nissan200sx.dk

[unique1]

i just checked a bare block here and the oil pump comes from the outside holes and the centre is the feed into the engine, so u need to feed oil back into the outside area, i just dont know how to do it without a remote filter setup as thats what ive used on the engines ive done. I had issues getting pressure with one of the engines and cranked for over 5 min, before trying this method and finally it worked. Never had any dramas with damage to bearings when i pulled it down. Dont get too stressed im sure theres a very very slim chance its damaged, plus with you feeding oil into the engine as u were doing i bet abit of oil went to the bearings anyway, enough to keep them from going dry.

good luck with it

Edited December 6, 2009 by unique1

[grigor]

I'm guessing you didn't assemble the oil pump with Nulon or similar?

Hoping you assembled all your big ends and mains, cams etc with Nulon.

Oil after filtration goes into the engine via the centre of the filter housing. Drilling goes straight through the block to the turbo oil feed on the left side.

You must remove the spark plugs and ensure you have oil pressure before you do serious cranking, 5 minutes is too long.

As explained by other posters, you've got to remove the air lock in the pump, probably by hand reverse direction cranking while adding oil to the outer ring of the filter housing.

You're going to make a mess but that's better than having a bearing pick up.

Vaselene is a bit too thick for an initial start-up as it can get forced into the end of the oil gallery thus starving those bearings until it's eventually squeezed out.

Thick engine oil is used a lot but as most Rb25/30 builds take a loooong time, it may have all drained back to the sump before start-up.

Best to use a proprietary purpose made product.

[brada31ke70]

put the spark plugs in and start it, it will have oil pressure, probably just not regesting on your gauge, the pump cant have an air lock because it pumps air until it pumps oil, there is no one way valve before it gets to the oil pump so it must pump air everytime you start it until it starts pumping oil, if that makes sence.

[nissan200sx.dk]

Thanks alot for the replys! I will try today to feed oil the other way in..

[STATUS]

put the spark plugs in and start it, it will have oil pressure, probably just not regesting on your gauge, the pump cant have an air lock because it pumps air until it pumps oil, there is no one way valve before it gets to the oil pump so it must pump air everytime you start it until it starts pumping oil, if that makes sence.

MATE THAT IS THE WORST THING TO DO... ignore this guy... ffs.

Not one part his post is factual. In fact if you reverse it it is about perfect.

Its quite common for airlocks between the pump and the pickup, when assembling it is best to use a small amount of assy lube in the rotors to cause a suction in the pickup, without the lube it is possible for the pump to bypass around it self and not draw up the oil.

A good trick is to cut the upper half off a filter, pull the guts out and fill it with oil (including the rubber anti return valve), turn engine over backwards until it draws all the oil into the engine. Prefill you new filter with oil and crank it to get pressure.

Edited December 6, 2009 by URAS

[unique1]

put the spark plugs in and start it, it will have oil pressure, probably just not regesting on your gauge, the pump cant have an air lock because it pumps air until it pumps oil, there is no one way valve before it gets to the oil pump so it must pump air everytime you start it until it starts pumping oil, if that makes sence.

lol and what if it doesnt get pressure? bang its f*kt, i think thats a stupid option mate i would never ever do that, it only has to idle for 10 secs at 1000rpm (and not get oil pressure) and it will be like cranking for 10 min without zero oil, not smart in anyones book.

[Swiper the Fox]

Best way to do it is to modify a gearbox filler syringe the following way...

pull the guts out of it and modify the top screw part to accept an airline fitting (weld it on). screw a ball valve into this fitting then attach an airline coupling. The lower hose needs to be locked on to the nipple with a wire tie and a barbed hose tail with a 1/8 NPT thread inserted into the end of the hose and wire locked also.

You then attach the syringe to the oil pressure sensor fitting on the engine and attach the compressed air line to the ball valve, fill the canistor with run in oil and slowly open the ball valve until NEARLY all the oil is deposited into the engine. Repeat this until 4 litres of oil is in the engine (4 times) checking to see if oil is seeping from the cam bearing journals through the oil cap hole. Fill the engine with the rest of the oil to the required level and start the bastard.

This is a much better method of priming the oil system.

Edited December 6, 2009 by DiRTgarage

[JonnoHR31]

start her up and sit on limiter straight away, if the motor survives you have oil pressure

seriously tho, once it has oil, cranking should produce enough pressure to show up on any gauge, should be enough to turn the oil light off too

[STATUS]

Best way to do it is to modify a gearbox filler syringe the following way...

pull the guts out of it and modify the top screw part to accept an airline fitting (weld it on). screw a ball valve into this fitting then attach an airline coupling. The lower hose needs to be locked on to the nipple with a wire tie and a barbed hose tail with a 1/8 NPT thread inserted into the end of the hose and wire locked also.

You then attach the syringe to the oil pressure sensor fitting on the engine and attach the compressed air line to the ball valve, fill the canistor with run in oil and slowly open the ball valve until NEARLY all the oil is deposited into the engine. Repeat this until 4 litres of oil is in the engine (4 times) checking to see if oil is seeping from the cam bearing journals through the oil cap hole. Fill the engine with the rest of the oil to the required level and start the bastard.

This is a much better method of priming the oil system.

We use an accumulator (canton) to pre charge all our engines too but i m guessing he doesnt have the equipment

[Marko R1]

MATE THAT IS THE WORST THING TO DO... ignore this guy... ffs.

haha dont hold back

i cracked up when i read this but it is great advice nonetheless