Morning all,
I ran into a weird issue this last weekend on the first start of my fresh rebuild/swap. When I started the car it would start just fine and idle but the car was idling at 2000rpm. I let it sit for about 10 minutes while messing with the tps screw and bleeder air valve. I could get it to settle down but either way....while the car was sitting there running, my aftermarket oil pressure gauge was reading over 110-120 psi of oil pressure. Does anyone know why this would be happening? I don't have any clue.

The stock oil pressure sensor has been taken out since the auto meter pressure sensor plugs into the same place. Either way any help would be very helpful. Thanks all.

I should expand on this a little. The current idle is at 2000 RPM...Thats when I see 110-120psi. I haven't been able to get my idle down yet but I think it may have something to do with my cold start thermal pallet being messed up. Would this cause the oil pressure to skyrocket? Also I blocked the oil squirters on my block and used the mazda bolts at the oil pump to block the old lines off there. Would this have anything to do with it? I basically premix now.

 

Did you replace the stock by-pass valve?
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/question-about-really-high-oil-pressure-754172/

 

No, in fact I still have the throttle body cooling system in place. What is this by pass valve? It stops oil from reaching the motor?

 

Sorry, should have been more clear...it's the "wax pellet" or "thermal pellet". I think the FSM refers to it as the "eccentric shaft by-pass valve"....same thing.

 

Ouch that sounds bad. What does replacing this involve?

 

IIRC, it usually fails in bypass mode. If you have high oil pressure all the time, it may have been eliminated - i.e., it does not have the bypass capability. Many rebuilders do this elimination to prevent failure of this device, which would result in dangerously low oil pressure when the engine is warm.

 

So what does this mean for me? How do I check if it's eliminated? How do I find out if thats the issue? Will my oil pressure remain this high forever then if this was infact eliminated?

 

Unfortunately, you've about reached the limit of my knowledge. I have never built an engine or modified or eliminated the bypass. My (original) engine still has it. Even in that case, my cold oil pressure on the stock gauge is over 100 at 2000 with 10W30 oil when I first start it. However, MANY engines are built without the bypass with good results. 110-120 psi is, IMO, not unusual at cold startup, especially with the bypass eliminated.

There also are other things that could affect oil pressure, such as a stuck oil pressure relief valve, or heavier than necessary oil viscosity.

Have you gotten the engine thoroughly warmed up? If so, what was the oil pressure then?

Maybe someone with more specific knowledge can chime in here.