RB25 OIl issues... ghost issues..

[stevespeed]

Okay so here is the deal, I have an R33 S1 RB25DET in my S13, etc, etc, etc.

Well I finally got everything cleaned up and running right and all that jazz.

I got paranoid about having oil issues and blowing an engine, I shot a rod through my stock N/A KA24DE before doing this swap so I am attempting to have history not repeat itself.

So I am cruising around and all of the sudden I start smelling oil smoke and currently I do not have a center radio/shifter bezel installed since I am fabbing up a nice little gauge pod for it, and smoke starts pooring in, and it gets worse as I boost more.

I look under the car and the oil pan is dented to all hell, but I am still showing good oil pressure during cruising/ light load.

I continue toward home and give it 3 good pulls in 1st, 2nd and 3rd gear. All 3 gears I saw the oil pressure go from around 75-90psi (Oil is 10W30 non synthenic) to straight 0.

It flutters nearer to 75-90 at around 5k and then by the time its past 6k its starts to fall and when its at redline its 0.

Help

[Joe]

find the source of the leak. is it a mechanical oil pressure gauge? im willing to bet money if it is, you have a bad fitting, broken line, etc.

if its an electric gauge you need to find out where the leak is first (see a recurring theme here?) then troubleshoot your electrical short.

whatever you do DONT DRIVE THE CAR.

*disclaimer* I nor NICO is responsible if you follow this advice and blow the engine *disclaimer*

this is what i would do, make sure your oil is full/proper, CLEAN THE f*** OUT OF YOUR ENGINE. sides, corners, back, bottom, etc. NO RESIDUE ANYWHERE.

put the car on jackstands (all 4)

start the engine. keep it in neutral. listen close for knock. if there is no knock, climb under, and look for the leak.

[stevespeed]

I got the leak narrowed down to the turbo side of the engine, I am thinking I either popped a crush washer on one of the turbo lines or a banjo bolt backed off. It is also possible that is coming from a valve cover.

The car is parked 100% still I change the oil pan. There is currently no knocks coming from the engine I have checked numerous times with a mechanics stethoscope.

I traced the leak to the back of the engine this morning, The top of the back of the head on the exhaust side is COVERED in oil. Ill post pics of my findings later tonight.

[Sil240]

Make sure there is no air in your gauge line. Air might give you a false or fluctuating reading.

[Darius]

It is likely the half-moon on the back of the valve cover is the source of the oil leak. It probably needs a good sized bead of RTV run across it again. A leak there will not affect oil pressure, so troubleshoot that as others have described.

[stevespeed]

Darius I think you are correct that the 1/2 moon is the issue. I do not remember coating those in RTV last year during the rebuild.

I talked with RacinJitter last evening and he seems to think that all the oil is trapped up in the head and there is just nothing left in the pan for the sump to pick up. His solution was add another 1/2 quart and see if it solves the issue.

its worth a shot

[Carl H]

oil pooling in the head can occur on rb engines but not to the extent which you have described...thats like saying that 4 qts of oil are in the head.
i'd follow joe's advice and clean the block and at a min just start it and look for leaks.
vaporized oil in the form of smoke means that it is getting hot enough to vaporize...look around the hot side of the engine.

[Darius]

Agreed Carl. Stevespeed- do you have a crank collar installed or is it still the stock oil pump drive on the crank?

[stevespeed]

Stock Drive, Stock Crank, the build was on an extreme bugdet, building an Rb while still in college working an Internship might not have been such a great idea as I thought.

The vaporized oil I have tracked to the back of the exhaust side valve cover, dripping down on to the exhaust and the turbo elbow/02 housing.

I can see massive oil stains on both those areas as well as the block near there. Ill take some pictures when I am underneath it later tonight.

Darius/Carl
How f*** am I with stock crank/stock collar? Should I start saving up for a Raw brokerage collar and an N1 pump?

[Carl H]

keep revs to stock limiter and as long as youre not making retarded hp you should be fine.

[stevespeed]

Okay, thanks Carl

Now the dent in the oil pan? Its about 1/4 inch to 1/3, maybe 1/2 inch at max. Should I be super worried about it? Or just fix the oil leak, add some oil see what happens maybe bang it out if I run out of ideas?

[Carl H]

i'd fix it...rather i would have fixed it before the engine went in.

[Darius]

My oil pan has a decent sized dent in it like you described but it clears the pickup so I didn't bother to change it out.

I'm still hoping that when your oil pressure gauge goes to zero at high revs that it is because of a faulty gauge or installation. Ideally, you would pull the motor apart and have a collar installed, but many have survived without one.

[stevespeed]

Right after the engine went in, I got laid off and ran out of money so I just put it together as best as I could and got her rolling.

My engine I know a fair bit about it's history so I decided agaisnt replacing the oil pump.

I found the issue, I have a leak at the oil return line from the turbo which would explain everything.

I am pretty sure the oil pressure drop at the high revs is lack of oil in the pan due to 2 reasons
1. Lack of oil in general becuase it blew out that return line
2. the kink in the line probably restriced oil getting back to the pan

HOPEFULLY i didnt blow the turbo

[stevespeed]

Soooooo I did some work on it
Replaced the Turbo Oil Return line,
Replaced the Turbo Coolant Feed line
Filled her up with just a touch extra bit of oil
Put on a new filter
Pulled the Valve cover to see if anything was wrong there.

Nothing, still the same issue.

But it still drove fine so I was like WHAT THE?!???!?!

So I went to good old Harbor Frieght bought an 8 dollar Oil Pressure Tester that happened to conviently have a 1/8th BSPT fitting on the end of it (blessing from God himself I am telling ya)

swapped out the Autometer Electric Sport Comp for that and just kept it in the bay.

Started the car up, GOt wayyyyyyyyyyy better oil pressure according to the Us General gauge, and once she was warm I got 30 psi around 1k, and 100 at Redline

The moral of today is! Dont buy old Autometer gauges....

and Mechanical Gauges FTW

[Carl H]

lol, i could have told you that...after seeing numerous boost gauges read 4 psi with the engine off?
no thanks, i'll pass.

[RustspecS13]

Nice fix. Be glad you didn't have to swap out the oil pump or pull off the pan. That would have sucked to say the least...

~Alex

[Darius]

Sweet!!