no oil pressure on a rb20

[brianb242]

whats up everyone, I'm new to the forum and thought i would introduce myself. I own a 95 240 sx, I've only owned the car about 2 weeks, it has a rb20 swap in it everything else is basical stock except for 17' wheels and a front mount. I've been working on cars for close to 12 years so I have a good bit of knoledge when it comes to working on them. I joined this forum hoping to learn more about my specific model, especially the engine. I bought the car from the previous owner with the rb swap already done. After fixing a few things and cleaning up some of the hack job this guy did I got the engine to crank. Engine didn't have the turbo or any of the intercooler piping connected as he took his aftermarket turbo out and kept it, original owner said that the oil light came on while driving and he thought it had a bad oil pump. I was very skeptical of his thoughts but since I gave him next to nothing for a really clean car with a swap already in it, (less than what it would cost me to buy the engine) I didn't mind havin to put the time or money into it. I have a hard time believing the oil pump just went out, out of nowhere so this is basicaly my thought... get a mechanical oil gauge and see how much oil press the engine actually has, then go from there, the questions I have are.... I heard if you run these engines hard you can tear up the rod bearings and that would be the reason for the low oil press(too much gap n the bearings) My oil sending unit is a single wire(maybe from the ka engine) does these sending unit have problems of going bad? how do i tell what year engine i have? Who is a good place to get parts if I decide not to replace the engine. just want to add I haven't been able to put the trans in reverse goes into every foward gear smooth as new. not sure on the problem yet just putting that info out there. thanks for the info and help in advance.

[brianb242]

another question.. the guy had a 6an oil line and fittings feeding oil to the turbo will that be a problem (to much volume) will it blow seals in the stock turbo?

[TheRBguy]

If its not building oil pressure the motor is probably already boned, and i know a kid that had an Rb20 in an s13 and he drifted it extreamly hard if he was against the rev limiter it wasnt running and that thing ran great till the day he sold it, Rbs dont have a problem handling abuse.

[brianb242]

If its not building oil pressure the motor is probably already boned, and i know a kid that had an Rb20 in an s13 and he drifted it extreamly hard if he was against the rev limiter it wasnt running and that thing ran great till the day he sold it, Rbs dont have a problem handling abuse.

I'm not eactly sure if it has oil pressure or not, not yet till i get a mechanicle gauge on it. all I have is a dummy light on, I don't know much about this engine so I posted to ask the guys on here who know more than me. i'm not asking anyone to do the work for me, I'm off today so I've spent all day on this site researching as much as i can to learn. I downloaded the service manual so I will be taking it apart here soon to measure the clearences and look at all the bearings. just looking for advice and answers to my questions. if it is shot no biggy. good to know these are good engines. I'm actually fixing the car to sell.

[TheRBguy]

The stock oil pressure sending unit does not go to the ECU i know that, in a skyline it just turns on the idiot light, so i would just take it out and come up with some sort of pressure gauge to thread in there.

[brianb242]

The stock oil pressure sending unit does not go to the ECU i know that, in a skyline it just turns on the idiot light, so i would just take it out and come up with some sort of pressure gauge to thread in there.

that was what I was planning on, in the future I may put a T fitting there and install a oil pressure gauge

[TheRBguy]

On my rb25 i just threaded out the stock one and threaded the aftermarket sensor in.

[334D]

The stock oil pressure sending unit does not go to the ECU i know that, in a skyline it just turns on the idiot light, so i would just take it out and come up with some sort of pressure gauge to thread in there.

incorrect dude, (not that its any help to the OP anyway) -32/33/34 RB skylines usually have an oil pressure sender + oil pressure gauge on the standard dash cluster. Can be difficult to get an easy and accurate a reading as it's not in PSI, but still good enough for showing that you have oil pressure.

Stagea's have the 'idiot light'

+1, thread in an aftermarket sensor, can't go wrong

[l0nestar]

The common failure point on the RB series engines is the oil pump drive (front of crank snout). I'm not familiar with bearing failure on the motors as a 'common problem'.

Yes, that is too large of a feed line for the turbo. find an OE hardline, or some OE upgrade replacement (non banjo style) lines. I think Circuit Sports makes some for ~$100.

I wrote this reply on Friday, sorry if these were already covered.

[brianb242]

The common failure point on the RB series engines is the oil pump drive (front of crank snout). I'm not familiar with bearing failure on the motors as a 'common problem'.

Yes, that is too large of a feed line for the turbo. find an OE hardline, or some OE upgrade replacement (non banjo style) lines. I think Circuit Sports makes some for ~$100.

I wrote this reply on Friday, sorry if these were already covered.

thanks for replying I didn't think the bearing idea was anything worth looking at either, just had to ask b/c of the source it came from, he's kind of a know it all..... and I figured the line was too big, summit has the fittings and a stainless braided line for about 80 bucks, as soon as the weather gets a little better I'm going to tear it down, theres snow in my driveway from our (white christmas). never heard of a part called a (oil pump drive) basically oil pumps go out on these engines? i've looked there about 180 bucks.

[l0nestar]

You have snow too? wonderful.

The issue is the material on the end of the crank that drives the oil pump. Lemme dig up a picture..


Crank Snout:


Oil Pump Drive:

This is a shot of the back-side of the oil pump. The flat spots in the center are what are referred to as the 'oil pump drive'.

A common fix is an 'Extended Collar'
Extended Crank Collar - Raw Brokerage

[brianb242]

You have snow too? wonderful.

The issue is the material on the end of the crank that drives the oil pump. Lemme dig up a picture..


Crank Snout:


Oil Pump Drive:

This is a shot of the back-side of the oil pump. The flat spots in the center are what are referred to as the 'oil pump drive'.

A common fix is an 'Extended Collar'
Extended Crank Collar - Raw Brokerage

Never had anyone refer to that part as a oil pump drive... learn something new everyday... what causes that to happen? poor design on nissans part? or..... I buy that collar slide it on, no machining needed? should I still replace the pump? does the drive get damaged in the process? I had to do something simular to my h22, where the seal wore a groove in the crank and you get his $10 sleeve that goes over it and your go to go.

[s14_sport]

The common failure point on the RB series engines is the oil pump drive (front of crank snout). I'm not familiar with bearing failure on the motors as a 'common problem'.

Yes, that is too large of a feed line for the turbo. find an OE hardline, or some OE upgrade replacement (non banjo style) lines. I think Circuit Sports makes some for ~$100.

I wrote this reply on Friday, sorry if these were already covered.

I have to chime in on this alittle....

The oil pump drive on the RB engines is a weakness...but, its far from a common failure point. I deal with alot of RB's and have never seen an RB engine fail due to the short crank snout. The most common thing I have seen in RB's is rod bearing failures and ringlands breaking and even when these engines were pulled apart there was no excess wear on the pump drive or crank snout.

[brianb242]

The common failure point on the RB series engines is the oil pump drive (front of crank snout). I'm not familiar with bearing failure on the motors as a 'common problem'.

Yes, that is too large of a feed line for the turbo. find an OE hardline, or some OE upgrade replacement (non banjo style) lines. I think Circuit Sports makes some for ~$100.

I wrote this reply on Friday, sorry if these were already covered.

I have to chime in on this alittle....

The oil pump drive on the RB engines is a weakness...but, its far from a common failure point. I deal with alot of RB's and have never seen an RB engine fail due to the short crank snout. The most common thing I have seen in RB's is rod bearing failures and ringlands breaking and even when these engines were pulled apart there was no excess wear on the pump drive or crank snout.

ok but would a rod bearing failure in my particular engine cause it to have no oil pressure?

[Genpac]

No, it would knock like a motherfuc&er. Careful of the sender threads, they aren't your typical 1/8"NPT, they're metric BSP.

[Gabes13]

Im pretty sure you have to weld that collar on, or else it would spin like a bearing haha

[brianb242]

Im pretty sure you have to weld that collar on, or else it would spin like a bearing haha

thats why i was asking what it takes to install it.

[brianb242]

No, it would knock like a motherfuc&er. Careful of the sender threads, they aren't your typical 1/8"NPT, they're metric BSP.

the threads are probably 10mm by 1.25 or 1.0 just to see what the engine would do I cranked it for a second after changing the oil, thank god no knocking or abnormal noises, I'm waiting on my sending unit for my autometer oil press gauge

[brianb242]

I installed the aftermarket oil press gauge and just like i figured still no oil pressure, will be tearing down the engine this weekend will be posting pics of what i find on here soon......

[RustspecS13]

Yeah that sucks, my friend just wrecked his S14 and the oil pan got dented. He did a burn out for fun after wards.

Then we go to put a new oil pan on it, and it had rod knock. The pressure regulator broke off when the sway bar hit the oil pan. That 10 second burn out just trashed the rod bearings. it hadn't been started since, but lots of metal every where.

Good thing its not my engine, so its just funny to me Hes experimenting with just putting new rod bearings and oil pump in it, and changing the oil a few times. We'll see how long it lasts

~Alex

[l0nestar]

Never had anyone refer to that part as a oil pump drive... learn something new everyday... what causes that to happen? poor design on nissans part? or..... I buy that collar slide it on, no machining needed? should I still replace the pump? does the drive get damaged in the process? I had to do something simular to my h22, where the seal wore a groove in the crank and you get his $10 sleeve that goes over it and your go to go.

No. You have to machine the crank down for the collar to be installed (normally). There are two different styles. The collar I had made, was designed to be heated first, and then slid on. Then has a grub screw that was tightened down after cooling, then was machined flat. I don't think I took a picture after the collar was installed..

[brianb242]

sounds like it just easier to replace the engine in my case.....

[brianb242]

well today i ordered a new swap, engine, trans, ecu, and harness. not a bad price for it...$1,400 I won't need the ecu or harness since the car had a swap already in it. whats a good price to sell the stuff i don't need? i was thinking 300 for the ecu and 100 for the harness, this sound about right? Any one looking for this stuff? I will post on the fs page w/pics

[l0nestar]

$100 on the ECU and I don't know about the harness. $100 sounds fair.