Loosing oil pressure on right hand turns. Any idea what would cause something like this? Odd thing is, a long sweeper (transition from full throttle accel to braking) doesn't get it to light up, but a slower, shorter turn does. Also, seems like oil pressure may be slow to build on start up, but that may just be my imagination.

Anyway, would appreciate any tips here. I'm hoping it maybe the sender wiring, or something else that won't keep me from hitting Roebling Road this weekend...
Ahmet

 

Dumb question but, I have you checked your oil level? If its low and hot, you'll get the light.

 

When you are losing oil pressure, what is the pressure dropping to?

 

Some on the e-mail digest suggest adding an extra liter of oil before the race and others suggest adding an oilpan baffle.

 

Could be a cracked pick-up tube.

On my race motor that blew-up a few years ago I studied my incar viedo and found something odd.

In the hard braking zones my oil pressure would drop to zero for a second or two. The come back up on the straights. Since only checked my pressure on the straights all looked fine untill the #2 bearing spun and blew-up the motor.

 

I'm leaning on a cracked pick up tube as well... This is too bad as dropping the oil pan is a procedure I cannot make time for this week.

Oil pressure drops as observed by the gauge. It drops to around 1 (but as you guys know, 1bar is very close to 0 on the gauge), and the pressure light flashes/comes on. What sounds like loud-ish valve tick is audible at idle after a somewhat lengthy drive.
Ahmet

 

A cracked pick up tube can be diagnosed by longer oil pressure build up times from a cold start. The crack will let air in and the system will lose its prime.

Chris White

 

Could be a cracked pickup tube (as has been suggested); this is particularly common on cars with "deleted" balance shafts. Also it could be a slightly low oil level. There's a design flaw in the Porsche engines where they placed the pickup too close to the return - thus, nice aerated "frothy" oil tends to get picked up causing a pressure drop under extreme conditions, rather than the nice "liquid" oil that normally bathes the pickup. This may or may not be related to the #2 bearing failure.

As has been stated, the likely fixes are (in order of increasing difficulty):
- add an extra quart of oil (keep it near the top notch on the dipstick, maybe even a little above.
- repair/replace the oil pickup tube
- add oil pan baffle

 

My last 86 had a cracked pick up tube with no other symptoms (when the balanceshafts were off timed). My current track car (87) DOES have balance shafts, and they ARE timed right... What else would cause a cracked pick up?
Ahmet

 

Cracked oil pan baffle??

 

Is a cracked pick up blatantly obvious upon inspection? I would think it cracks right where the tube extends out from the mounting boss, correct? Is it something worth running a weld bead around while you're welding a collar around the pickup, or would that risk making things worse?

 

Make sure the crank bolt is torqued to spec. Also replace the opv. before you pull the pan. If you still have to pull the pan I suggest you also redo the loctite gasket on the oil pump. I have seen the loctite crack over time.

 

Ian, I don't think it's going to end up being the oil pan baffle as this wouldn't do anything for oil pressure on start up. Also, even without a baffle, the light shouldn't come on for any light cornering...

Dan, on my 86 the cracked oil pick up tube was not easy to spot at all. It was a VERY weird thing, hard to describe. It was towards the top of the pick up, but not along the joint, so adding a bead there may not do anything. I will take pictures of this pick up tube if it is indeed cracked.

Jimbo, why do you suggest replacing the relief valve before pulling the pan (I suggest this is what you mean by OPV?). Do you know of a way this valve can cause the problems I'm describing? (Start up/low general oil pressure, but perhaps not lower oil pressure on right turns than left)?
Ahmet

 

Sorry. OPRV do a search. There is an updated valve available from paragon.

 

Yes the OPRV can fail. I don't believe that I can fail in such a way as cornering loads can cause problems. If fails it will fail just the same with car sitting stationary.

If the tube is cracked it can physically move in the pan when cornering. This opens the crack enough to suck air and less oil. Once the car levels off the tube moves back and the oil flow is returned.

The car usally won't last long like this.