Sudden Zero Oil Pressure After Pump Change After 30Mins Of Driving!

[Blue32]

Guys,

Thrown a curve ball on a recent oil pump change on an RB25DET. Brief schedule of events:

Built motor run in and no problems, customer wanted to change N1 oil pump to Nitto for obvious reasons.

Pump change completed, all normal considerations attended to (prime pump etc) and it was cranked with oil pressure(no plugs / load on engine).

Engine was then prepared and started to bleed coolant and oil level was checked at correct level both BEFORE and AFTER initial start. Oil pressure still normal at this stage.

A few starts later, and the customer drove the car to tuner to have dyno run, and upon shutting the engine off oil pressure was fine and normal, and upon restart NO OIL PRESSURE (verified on factory light, oil pressure gauge and Defi Oil Pressure gauge / ie 3 independent sources. Tuner pulls of Turbo oil feed, starts car for a brief moment, no oil coming out. Car towed at this stage.

I get it back, suspecting blocked pickup. Remove everything including oil pump - no obstructions SEEN however I have pressurised oil system using AIR PRESSURE and seen a corresponding pressure indication on Oil pressure gauges. Oil pump was stripped, no blockage / foreign matter, gears excellent and no witness marks anywhere. Repacked oil pump with vas, and reinstalled. Via external oil filter block, pressure side of oil system back to pump primed with around 600ml or so of fresh oil (didn't measure) till full and clear of bubbles/air. Filter filled with oil, cooler pressurised with oil (using gearbox syringe and fitting) and then engine cranked once again (no plugs) with oil pressure coming up within 10secs of initial crank and normal limits.

I am confident of the installation (both times) however although I have got oil pressure back, I wonder what the cause was in the first place?? I have covered everything twice and simple things like the oil filter installation is correct. Has anyone experienced this phenomenon??????

I call for experienced engine builders etc here, please don't tell me once you filled your lawnmower with fuel and now you can service the QE2.......

[rob82]

Failed oil pickup rubber seal between pickup and block? Scary putting things back together without a cause.

Edited March 19, 2011 by rob82

[DVS JEZ]

+1

Did u put it back together with a new seal

[The Dan]

Does it have an oil cooler with a thermostat on it? or any other type of oil control device inline with the system?

[Blue32]

No thermostat on the oil cooler setup, and seal on pickup was fine. No o ring on the pickup used - there is a gasket. I agree about the no cause found..... however there was no oil pressure previous and I have made totally sure the path from the pickup to oil pump to filter and back to block (where the factory oil pressure sender / light switch) is totally unobstructed.

[J - Rad]

Have Adrian or you contacted Paul who built it? He may have an answer. I'm not quiet sure how it can become blocked if its done a track day with the N1 pump and it never had a problem. The one thing it did do is suck all the material out of the pod filter as it was mounted too close to the turbo and was a cheap pod filter. But I don't see how any of that material could of made its way through the motor?

[J - Rad]

Have Adrian or you contacted Paul who built it? He may have an answer. I'm not quiet sure how it can become blocked if its done a track day with the N1 pump and it never had a problem. The one thing it did do is suck all the material out of the pod filter as it was mounted too close to the turbo and was a cheap pod filter. But I don't see how any of that material could of made its way through the motor?

[Blue32]

Doesn't sound like fun, although I agree that shouldn't affect the oil pressure issue it has currently experienced

[T04GTR]

perhaps it has a sticky pressure relief valve.

[Blue32]

Do the nitto units suffer from this though??

[rad100]

anything besides a smashed oil pump that could prevent oil pressure?

[rob82]

perhaps it has a sticky pressure relief valve.

If that were the case surely it would be more likely to happen after a big rev. Its very unlikly to be a sticky PRV after an idle shutdown.

[Blue32]

I don't believe it is the PRV either - no witness marks on the piston, and it needs the max oil press (120psi) to actuate, therefore ruling it out from the idle shutdown and restart scenario.

[Supa Steve]

Experience tells me whoever did the pump change put the oil cooler/relocator lines ass about and this fed pressure up the inside of the oil filter forcing it to reverse flow. This mistake has caused the engine to starve of oil due to the anti drain back valve inside the filter. When it was returned to the person who did this they realised what they had done and put them around the right way. They then gave away they may have already knew the cause by posting this line on the internet I have covered everything twice and simple things like the oil filter installation is correct.

I could be wrong but as you asked for advice from someone with experience i thought i might give some.

[ronnydotk]

Experience tells me whoever did the pump change put the oil cooler/relocator lines ass about and this fed pressure up the inside of the oil filter forcing it to reverse flow. This mistake has caused the engine to starve of oil due to the anti drain back valve inside the filter. When it was returned to the person who did this they realised what they had done and put them around the right way. They then gave away they may have already knew the cause by posting this line on the internet I have covered everything twice and simple things like the oil filter installation is correct.

I could be wrong but as you asked for advice from someone with experience i thought i might give some.

It would never have had any oil pressure if this was the case (or only what could get passed the prv) and as blue32 said after about 10sec of winding 1st time around oil pressure was seen. And winding an engine on the starter isn't going to open a prv.

[rad100]

and the fact that 40odd minutes of driving from home to the tuner had perfect oil pressure..

[Supa Steve]

guys the anti drain back flap will pass oil till the pressure eventually forces it to completely block flow. Im sure if you cut open the filter the anti drain back flap would be marked where it was forced against the holes. If it had no anti drain flap it may have been filter element or bypass failure as ive also seen the filter membrane eventually collapse from running in reverse and also the internal bypass valve collapse in others. Get the filter and inspect it as there are clues left at every crime scene that tell the story of what happened, you just need to be experienced enough to know where to look.

Engines dont mysteriously loose oil pressure then have it return unless there is a root cause. When you consider it only occurred after the engine had been worked on and now pressure has returned after it had been again worked on with no component change leaves no doubt it was some human error that had caused it.

What size sump does it have? As the only other thing that may have happened is the nitto pump has emptied the sump during the 40mins and the oil system had developed a big air lock unable to move any oil that had since returned. Just a thought.

Edited March 22, 2011 by Supa Steve

[Blue32]

Experience tells me whoever did the pump change put the oil cooler/relocator lines ass about and this fed pressure up the inside of the oil filter forcing it to reverse flow. This mistake has caused the engine to starve of oil due to the anti drain back valve inside the filter. When it was returned to the person who did this they realised what they had done and put them around the right way. They then gave away they may have already knew the cause by posting this line on the internet I have covered everything twice and simple things like the oil filter installation is correct.

I could be wrong but as you asked for advice from someone with experience i thought i might give some.

I thank you for your input - and you are right that this would indeed cause the issue, albeit with different characteristics (like it wouldn't make 8 Bar of oil pressure when cold and a few revs onboard if the PRV was venting oil straight back to the sump). The filter is still sitting on the workbench and you are welcome to inspect, however you will find no problem as the filter / cooler setup has not been manipulated. It also begs the question why would I bother to post this quandry if I knew the problem in the first place??

You have been helpful outlining a possible cause - as this is the reason I started the thread in the first place, however I can assure you that the reason is definately not what you have posted. Any other ideas?

[Blue32]

What size sump does it have? As the only other thing that may have happened is the nitto pump has emptied the sump during the 40mins and the oil system had developed a big air lock unable to move any oil that had since returned. Just a thought.

This is another possibilty - factory sump however Adrian stated the car was being driven sedately to the tuners (obviously prior to tuning) and I wouldn't expect a high oil flow / feed situation to the head - especially on the street. The engine also runs head restrictors and external oil return to the sump. Also, once the oil pump is past initial prime and coated with oil, the pump should pump air. Many Rb's that spin bearings on the track etc suck air only for a short period of time then regain oil pressure - although by then the damage is done.....