Rebuilt Rb26: No Oil Pressure + Knocking Noise

[ryu1605]

Hey guys

My boyfriend and I just bought a 1989 r32 gtr Nismo edition with a fully rebuilt engine. Some engine specs are:

- N1 block

- r33 gtr crankshaft

-wiseco forged pistons

-h-beam conrods

- N1 oil pump

- nismo big end and main bearings

- tomei sump baffle

We took it out for a bit of a run today and had to get it towed home by the end of it. We booted it a bit down the straight and wouldn't have even reached 200kms, revved it, and then downshifted to 3rd gear when we heard a knocking noise coming from the engine. We pulled over into a carpark for a look. There was no smoke, no leaks, no smells under the bonnet and the engine wasn't overly warm. There was just a clunking noise that seemed to follow the revs. Turned it off for about 45mins and then turned it back on to find that we had lost oil pressure to the point that the warning light was coming on. Decided that we should try and drive it to see if the oil pressure light would go off and the engine seemed fine. It turned over as normal, wasn't overheating, still had all of it's power but there was still the knocking noise. We checked the oil and it was normal, we also checked the coolant, checked to see if any carbon crap was being blown out of the exhaust and all was normal.

We have read a lot about rb26's and the oil problems that arise with older models however seeing as this is a fully rebuilt rb with a N1 block that has only done roughly 25000 kms we never expected to run into the dreaded rb26 oil problem in such a short space of time without even pushing the engine.

The fact that we lost oil pressure isn't a good sign and we are hoping that we haven't spun a bearing. What else could it be? Rod knock? Destroyed oil pump crank collar? A bad tune?

We are going to drain the oil tomorrow morning and hope like hell that there are no metal shavings/bits floating around that would mean a complete engine rebuild so soon.

Any ideas? Has anyone else come across anything similar?

Thanks guys for any advice!

[Moodles2]

There won't be a crank colar, R33 GTR crankshaft has a long oil drive.

Was the sump overfilled? (in most likely hood: oil starvation. N1 pumps will fill the head faster than a stock pump, without a sump extension or oil restrictors or overfilling to 6l. By the time you reach the end of a straight the sump will be bone dry)

How old was the oil pump? (recently made as in 2 years ago, the N1's have a bad reputation, older pumps were fine)

What oil did you use at the track?

Do you have an oil/air seperator or aftermarket cam baffle plates to return blowby oil to the sump instead of back into the intake and out the exhaust?

[Buraz]

Unfortunately it sounds like a spun bearing! Could be that the oil pump failed, which resulted in a spun a bearing due to no oil pressure. I hope I'm wrong!

[ryu1605]

There won't be a crank colar, R33 GTR crankshaft has a long oil drive.

Was the sump overfilled? (in most likely hood: oil starvation. N1 pumps will fill the head faster than a stock pump, without a sump extension or oil restrictors or overfilling to 6l. By the time you reach the end of a straight the sump will be bone dry)

How old was the oil pump? (recently made as in 2 years ago, the N1's have a bad reputation, older pumps were fine)

What oil did you use at the track?

Do you have an oil/air seperator or aftermarket cam baffle plates to return blowby oil to the sump instead of back into the intake and out the exhaust?

The sump was overfilled when we checked. The N1 pump was a 2009 model and I have read that N1 pumps aren't the greatest but better than stock. The car doesn't have cam baffles or an extended sump. Don't think the previous owner really drove it much as it has pretty much been a weekender for him mostly living in the garage.

The more we read into it, it sounds like the oil pump is destroyed. Better than a spun bearing though I guess. Only time will tell, we'll find out tomorrow!

What pump do you recommend? And other than putting cam baffles in and an extended sump, are there any other improvements that we can make to lessen the chance of something like this happening again?

Really appreciate the response

[DVS JEZ]

If it is the pump then chances are thebearings will be damaged and bits of the pump will be through the motor.

Will atleast need a clean out and new bearings+ pump

[smithy85]

Big name jap brands like Tomei and Jun for the oil pump are more reliable than the N1 but you pay way more for the them.

Does your engine have the head oil drain mod that is quite popular?

[ryu1605]

DVS JEZ: That thought has definitely crossed my mind.

smithy85: Yeah its got the 2 lines coming out the top/back of the engine leading into a catch can where the battery used to be

Cheers for the replies guys

[smithy85]

Not the drains from the breathers.

Rather drains drilled into the back of the head that drain directly into the sump - stops the oil pump from getting carried away with itself and pumping more oil up to the head than the head can drain back, leading to oil starvation.

Do a search on here for the oil control thread, heaps of info on it.

[ryu1605]

Not the drains from the breathers.

Rather drains drilled into the back of the head that drain directly into the sump - stops the oil pump from getting carried away with itself and pumping more oil up to the head than the head can drain back, leading to oil starvation.

Do a search on here for the oil control thread, heaps of info on it.

It has drains in the back of the head with lines that go straight back into the drivers side of the sump.

Drained the oil out of the sump last night and couldn't see any signs of metal in the oil so am now just confused even more.

I was under the impression that generally when rb26's lose oil pressure and develop a knock they dump almost all the oil out into the engine bay. Ours has no signs of oil being anywhere that it shouldnt be. The sump was full after it lost oil pressure, the catch can isnt full, theres no oil leaks anywhere.

As you can imagine we have a million and one questions going through our heads at the moment and are just really confused lol.

We know that the only real way to find out for sure is to get it into a workshop to get checked out but any other ideas you guys might have would be greatly sppreciated!

Cheers,

Drew

[Tengoku Imports]

Hi Drew,

Sorry to hear about your engine dramas. I've blown up more than my fair share of them (Usually late model Toyota ones, and in exactly the same fashion), so I know how you're feeling right now.

Going from what you've described, it sounds like an oil pump failure. There's plenty of oil in the sump, but no oil pressure. So the pump is not sending oil through the engine. When you're at the high rev range of the engine, it gets really hot, and without any oil, the bearings will fail.

That knocking sound is a spun big end bearing, which is basically a bit of metal between the crank and the piston. That knocking sound is the sound of the piston hitting on something, and as revs increase, your crank turns faster, and the bearing hits on whatever faster.

It's very unfortunate to have happened, but hopefully there's no damage on the block, and you can just replace the bearings and go at it again. If there's no metal in the oil, then it's a good sign. You'll need to have the engine professionally checked out to be sure anyway.

Good luck mate, and PM if you want to talk more about it. Happy to chat over the phone.

Tiang