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Oil Pressure Drop On Boost.

EAT26

By EAT26,
in Engines & Forced Induction

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GTRsean Grand Master

GTRsean

Posted
Posted

Nope, never had that problem.

That could be from excessive blowby causing oil buildup in the breather pipes on the cam covers, then getting sucked into intake..

turbo oil seals,

valve stem seals worn, unlikely.

Do you run an oil catch can?

GTR_JOEY Grand Master

GTR_JOEY

Posted
Posted

Car isnt actually running yet, just trying to get ideas for making 400rwkw more reliable

EAT26 reckons his car blows a tint of blue smoke now at high rpm when free reving.

But yea will definatly be running a catch can

GTRsean Grand Master

GTRsean

Posted
Posted

what oil pressure gauge u got? stock seems to be a little slow in registering low pressure

Never seen it on a stock gauge. They are slow so that normal people don't freak out when the gauges swing around!! :D

I've only seen it on aftermarket gauges.

GTRsean Grand Master

GTRsean

Posted
Posted

I'd say the gauge has electronic dampener to delay the oil pressure sender input.

Don't think that anyone has tried modding the gauge. I put an aftermarket oil temp and pressure gauge in the glovebox for 32GTR, stealth!

Don Dada Mentor

Don Dada

Posted
Posted

Yea...Dont think you would pick it up with the oem gauge as its slow.I have a mechanical guage so you see it instantly.

Dont know why nissan didnt fix this in the later gtrs. They could have at least redesigned the dip stick, as I'm sure this caused quite a few spun bearings

GTRPSI Mentor

GTRPSI

Posted
Posted

Best way to confirm your not dropping your oil level by building it in the head is to drive it warmed up at low RPM and then drop it into second and boost it.

At low Rpm there should be no oil build up in the head and a squirt to the redline in second should not be enough time to drop your oil level low by building the oil into the head.

If its still dropping id be looking at the oil pressure sender, oil pump pressure relief valve or something more serious like rod bolt stretch, loose main cap girdle etc which may lead to a spun bearing.

Try a thicker oil see what happens.....

mico Proficient

mico

Posted
Posted

when u put 6l in did it fill up to the hump tho ?? did u try it on the dyno with the extra oil in (no g's there) ? get an aftermarket gauge, make sure the oil is up to the hump and if it still drops its almost gotta be the backing plate screws coming loose.

GTRNUR Grand Master

GTRNUR

Posted
Posted

I had this same issue when fast cornering back when I had a stock motor/sump setup in the car. It would happen when coming out of a corners and accelerating onto the straights in 2nd gear. This was when competing in sprint events.

The issue first appeared when I purchased a good set of semi slicks. Basically once I got the suspension and tyres sorted so I could maintain good cornering speeds and get good mid corner grip, I would lose oil pressure about 20-30m out of the corners. The extra cornering grip was allowing me to get on the throttle a lot more mid corner, resulting in more cornering G's, less oil depth around the pickup and more oil in the head.

A couple of the on camber corners that were angled up hill were the worse than other corners. Possibly because my balls don't permit me to push as hard in the off camber corners where the sand trap is actually a swamp.

5.5lt+ (probably not quite 6lt) made no difference, but I did try the overfill to the hump. I was using 10w60 in summer, and in 35 degree heat. If anything I think that using a ligher grade oil would help more, as it will return to the sump faster from the head, and also from the sides of the sump after cornering. So I think that using a 10w40 and only driving it hard when your oil temps are 90+ degrees would help. Higher temps lowering viscosity.

Stock sump setups just arent good enough for high lateral G cornering. A stock GTR engine is not a motorsport grade engine. Its a fast street car engine. Once you are in 3rd or above then the G's arent enough to get the oil away from the pickup so your oil pressure drop issue shouldnt be happening then. Thats unless you have a modified engine etc, in which case hopefully you've upgraded your sump capacity and added trap doors as well.

Im sure many will disagree with this having not experienced oil pressure drop issues once they over-filled. It all comes down to how you drive, how fast you can corner and especially the track.

  • 2 weeks later...
sikmechy Rookie

sikmechy

Posted
Posted (edited)

Or if it the sump baffles that are the problem then u could just take the stock baffles out and decide where they would be more effective or weld more in. I think thats high on the cheap list

Edited by sikmechy

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