Recently did a rebuild but I'm having high pressure over 120psi and oil leaking through downpipe from turbos, had single thought it was bad and running oem twins and still having the same issue, ran it without turbos and headers, did not smoked what so ever but oil pressure gauge was still hitting 120psi max, yes i had the sender replace but still having same issue
anyone know what can be the issue here?

 

Did you do any oil pressure mods when you rebuilt the engine?

Dale

 

I did not, the only thing I did was streetport but otherwise everything is fully stock

 

What oil viscosity is used? At what rpm are you seeing the 120 psi reading?

 

Using 20w-50, car hits the max 120psi over 2krpm

 

Pretty stiff oil. Is that with the engine at full operating temp? If not, what’s the ambient? And maybe see where you’re at once the engine is warmed up.

 

Ambient temp around 75F, I see the pressure sits around 60psi at 900ish rpm but over 2krpm, hitting max and turbo leaking oil via downpipe

 

Perhaps it's overfilled? 4Qts is required with filter.
I think it's likely it's over filled.

Measure your dipstick after oil temp comes up, shut off and have it sit for a minute.
Oil temp comes up much later than the water does, so good 2~4 miles cruise to local grocery and back will do.

Unless you over torqued the pressure nuts on top of inside front cover or at the back, which are left alone in many cases in rebuild, can't see a reason why idle pressure is at 60psi.

 

Do you have a PCV setup of some kind? You didn't cap the nipples on the oil fill neck or anything?

This normally is caused when people try to crush the oil pressure regulator in the rear iron to raise oil pressure and they go too far.

You also will want to get a mechanical oil pressure gauge to make 100% sure the stock sender and gauge are telling the truth.

Dale

 

my stupid ness put 5quarts, but i did drain excessive out, still having some oil leaks but idle around 50ish psi, yes im still running pcv still

 

OK yeah an over fill of oil will cause some major problems. With the right level you should be good.

Typically you want it 3/4 of the way on the hash mark on the dip stick.

Dale

 

not on a rotary......but I recently switched from fram to Wix oil filter. It dropped my OP from 50 to high 30's/40

 

Are those readings when the engine is at full operating temp?

 

fully operating temp sits around 55ishpsi @ 900rpm, over 2500krpm oil pressure hitting max 120psi
But still seeing oil still being burnt in downpipe

 

With an stock engine running 20w50 oil and Wix (NAPA Gold) oil filter and the factory single oil cooler from a Base model, I've never seen more than 110psi oil pressure as measured by an aftermarket sensor mounted on a Banzai-Racing oil filter pedestal. When the oil is hot (105 degC), pressure might be as low as 25-30psi at 950 RPM idle. Here's a chart showing my ECU's logged Oil Pressure vs RPM during about 1 hour of running at a recent autocross. The color of the points is based on oil temperature, so the blue-colored spike at 1500 RPM when the engine is warming up in the pits.

 

It's just odd it's high oil pressure, been using same oil and filter brands before I had the rebuild

 

How good is the gauge? If it mirrors the reliability of readings of some fuel pressure gauges on the market, I'd be double checking.

 

How much psi should I be getting at startup as I'm still getting over max @ 1800rpm, unsure at this point

 

The shop manual says you should have a minimum of 50 psi at 3,000 rpm when the engine has warmed up to operating temperature, but that assumes you are running the recommended oil viscosity of 10W-30.

 

Max pressure at 1800 RPM when the oil is cold sounds pretty normal to me, at least with 20w50 oil. I see about 95-100psi when the oil temp is 15 degC, idle speed about 1500 RPM. Pressure starts to decrease after running for 1-2 minutes (20 degC), and is near normal after running for 3-4 minutes (45-50 degC).

I haven't tried thinner oil recently, since it tends to get diluted with fuel eventually. If there's harm in running rotary engines with thick oil, I haven't heard about it.

 

Would the oil relief valve would problem here?

 

just tested with mechanical gauge, still gives off the same readings on the dashboard

 

Unpleasant option after a rebuild - regulator piston stuck with grit or debris?

 

One thing you haven't answered I don't think is your PCV system, there are 2 nipples on the oil fill neck. If they are capped up you will have weird oil problems.

For testing purposes just start the car with the oil fill cap off and see if anything is different.

Typically a rotary fully warned up will be around 30psi of oil pressure at idle, 60 psi at 3000 RPM. That is healthy.

It's also possible something is wrong with the oil control rings in the engine and you're getting crazy blow by into the oiling system.

Did you build the engine yourself or did a shop build it? What was the reason the engine was rebuilt? What all was done when you built it?

Dale

 

I'm still running the pcv via oil filler neck to UIM, I did the rebuild myself, new housing rotor, seals and O rings, had it balanced and such. Compression over 105, reason why front rotor blew as turbo over boosted (bought used twins for this build 50k miles on them as mine were 134k),
​​I ran the engine without turbo, looped everything but I don't see crazy smoke issues unless with turbos due high pressure typically