# New RB, No Oil Pressure ?



## 900ss (Aug 16, 2010)

Has anyone had any experience of a new built RB motor losing oil pressures on start up ? 
Long story short I’ve put together a RB25/34 using a new built spool 3.4 bottom end, new nitto pump and fresh built 2.5 neo head.
Engine is all but built in the car but now on cranking with no plugs fitted and no fuel flowing I’ve noticed after an initial build up of oil pressure I now have none!
On initial cranking oil flow could be seen working its way up to the head and cam caps as well as feeding the turbos oil line, but after a short while the oil flow has stopped 
After lots of checking and looking on the net ive seen a few cases of fresh built RB motors NOT building oil pressure atall until the engine actually fired and started, but none mentioning pressure building up, then dropping back off ??
Any help appreciated as for the life of me I cant see why its done this … ?
tbh I rather not fire it up as is unless a final resort, or unless anyone knows of a cheat to help get back cranking pressure ??
ta


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## TABZ (Apr 30, 2003)

How are you checking pressure? Oem gauge or after market at the housing?


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## 900ss (Aug 16, 2010)

Oem gauge + rocker covers removed watching oil flow to cams as well as watching oil flow from turbo oil feed 
On cranking I now have none


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## TABZ (Apr 30, 2003)

I done something similar during fitting a rebuilt turbo.
I found by placing an oil pressure gauge at the housing it would register pressure but no sign of oil at turbo or rockers until it fired up.

The oem gauge wasn't accurate or reliable.


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## 900ss (Aug 16, 2010)

Cheers Tabz 
Lazy gauge I could live with but no physical pressure doesn't seem right 
Maybe firing it up is the only option to get the pump fully primed ?


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## TABZ (Apr 30, 2003)

After all you've been through getting it to where it is, I really hope it's something simple.


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## FRRACER (Jun 23, 2013)

Keep cranking it with cas disconnected it took mine about 30 odd seconds till the pressure began to rise.


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## mgtkr1 (Aug 27, 2015)

can you not prime the pump manually? Ive had it before where it wouldn't show pressure for love nor money. wipped the pressure relief spring out, pour oil in and bingo,healthy oil pressure


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## Dan ep3 turbo (Sep 29, 2013)

Are you sure you have enough clearence between oil pick up and sump pan?


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## teetee (Jun 30, 2013)

When I build my ca18det, I didn't get oil from turbo oil feed hose after cranking a minute, then I started engine and after couple seconds I have oil pressure. Engine has been good for ten years now.


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## dA_RoB (Dec 21, 2012)

With the OEM gauge I don't see any oil pressure until engine is started.
Normally I crank it for 10 sec before first start of the day!
Nothing to be concerned about! 
However, in the future when going to a new ECU, I'll change the oil pressure sensor and feed it straight into the ecu. The gauge in the cockpit really is just a rough guess!

BR
RoB


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## Dan ep3 turbo (Sep 29, 2013)

When my 26 first was turned over after build I took plugs out and with tomei oil pump I see 1.5bar oil pressure on turn over and that was pressure at turbo oil feed. A good engine with decent pump should easily see 1-2bar on turn over


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## 900ss (Aug 16, 2010)

Cheers all, will try the relief valve to see if that works.
As said what doesn't add up is it HAD oil pressure as it could be seen working out of the cam caps and from the turbo feed line, but now has stopped.
Dan, oil pickup is semi golf ball shaped so no chance of it being bottomed out (would have never got the sump on if it was)
The only thing that I didn't get right (wait for it ) was on cranking the battery went flat, so unless the oil somehow drained back due to not being pumped fast enough and now has lost the initial oomph it would have had by the pump no longer being prepacked ?
btw have already got it cranking at speed now, plugs removed .... 
Will try it all again today to see how many more circles I can go around :runaway:


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## R32 Combat (Jan 29, 2004)

Maybe an oil squirter has broken off and all the oil is returning to the sump from there.


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## davew (Apr 28, 2003)

R32 Combat said:


> Maybe an oil squirter has broken off and all the oil is returning to the sump from there.


we had similar, a local customer had his "professional" mate build the engine for him on the cheap. He forgot to fit the oil squirters completely


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## 900ss (Aug 16, 2010)

It isn't fitted with oil squirters being an RB30 based engine so can't be that ...


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## R32 Combat (Jan 29, 2004)

OK, also check oil core plugs. A leak is very obvious though.


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## FRRACER (Jun 23, 2013)

Is the sensor plugged in?


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## 900ss (Aug 16, 2010)

Well its sort of sorted itself, sort of. 
After cranking and cranking for what seemed like a minute plus oil pressure finally worked its way back to the cams and turbo line.
Gauge read as it should to but .... the second I stopped and then tried cranking again pressure was lost again 
It did this a couple of times so pressure is building if cranked long enough 
tbh am now thinking I need to fire it up to get it to fully build and hold pressure ??
I did try the relief valve on the side of the pump to, but no way did the union want to budge.
Being a brand new pump I didn't want to crack the case in forcing it either ...


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## Lith (Oct 5, 2006)

How is this build coming together? Did you end up with the EFR9180?


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## 900ss (Aug 16, 2010)

Yes its slowly coming together, but working outside doesn't help in this weather.
Have just had this new exhaust manifold fabricated so I can start back on it soon 
Yes that turbo fits in there a treat and at least I can shut the bonnet now - just :chuckle:


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## mgtkr1 (Aug 27, 2015)

did you solve the oil pressure niggle?
looks like a serious build


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## teetee (Jun 30, 2013)

tight fitment, compressor housing is very close to chassis.


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## 900ss (Aug 16, 2010)

mgtkr1 said:


> did you solve the oil pressure niggle?
> looks like a serious build


No not yet, but that's only down to me not working on it
But I fully intend to pull my finger out now I have more time on my hands 



teetee said:


> tight fitment, compressor housing is very close to chassis.


It is and yet to see if I get away with it or not 
Maybe have to rotate and shave the housing a rats **** to give me a little more room


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