Too much oil pressure.

[disco stu]

It's pegging the guage. I know the guage is close because I checked the resistances of the sending unit at certain pressures and it is right on with what Autometer told me it is supposed to be. I am running a HV front cover set up with the pump cover on the loose side. All oil passages thoroughly ported and radiused, bearings feed holes opened up to better match feed holes in block etc. Oil pressure is a tick under 25 hot.

I have to run a 40psi relief spring which keeps it at around 70 psi in upper rpms. The relief is not shimmed or blocked, and slides in and out perfectly freely.

Bearing clearances are all at about .0017 with the coating on them.

Pretty strange, I'm stumped.

 

[Black Car]

What kind and weight of oil are you using?
If dino( regular) & 20w50 or straight 30 or 40. Then use 10-30.
Some people don't like synethic oil but they are usually thiner than convensional (sp) fossil/dino oils.

Gary

 

[disco stu]

5w30 synthetic.

 

[Jerryl]

It's pegging the guage. I know the guage is close because I checked the resistances of the sending unit at certain pressures and it is right on with what Autometer told me it is supposed to be. I am running a HV front cover set up with the pump cover on the loose side. All oil passages thoroughly ported and radiused, bearings feed holes opened up to better match feed holes in block etc. Oil pressure is a tick under 25 hot.

I have to run a 40psi relief spring which keeps it at around 70 psi in upper rpms. The relief is not shimmed or blocked, and slides in and out perfectly freely.

Bearing clearances are all at about .0017 with the coating on them.

I have similar readings.
Mains at at 0.0018, HV pump, 60 psi spring, 5W30.
Cold pressure 45 @idle. Hot around 18@idle.
Warming the motor up (around 2K rpm) I have seen 70 PSI. Always 38-40 at highway speeds warm.
I do not have a calibrated gauge.

Not sure if it is anything to worry about, but I am no expert.

 

[GNVenom]

I had the same condition happen to me before. Turned out I blew a head gasket and the milkshake oil must have caused the super high pressure.

Still couldn't understand why the pressure went so high. Check your dipstick...

John

 

[disco stu]

Looks good. I only have 5 low boost passes on it too. Last time I dumped water in the crankcase my pressure went down.

It's very weird. When I primed it it took little effort to spin it. The drill hardly torqued over.

High oil pressure on a Buick? Have I seen it all now?

 

[DR BOOST]

how many miles on the motor? 25 hot idle doesnt seem high at all. thats where my motor has been for the past 5000 miles.


surej

 

[disco stu]

Next to none. I am glad it has 25 at idle. But am worried about who knows how much over 100 psi it is during a run.

 

[Lee Thompson]

Imo

Sound to me like you built a solid eng. with good clearances and that is EXACTLY why I do not recommend a HV cover. Now that it is on I probably be looking for ways to create a leak. How about opening up the 1/8 tubing (.050) hole feeding the cam gears?
I see 90 PSI @ the traps--60 cruising--no leaks so far.

 

[cool 84]

I have the same problem. I make sure to let mine idle for 10 minutes when cold before I hit the gas. I've blown the filter off with it dead cold and rpms hitting 3K.

I did have something like 80psi hot idle pressure when I blew a headgasket once. I had more water than oil in the pan.

 

[disco stu]

Sound to me like you built a solid eng. with good clearances and that is EXACTLY why I do not recommend a HV cover. Now that it is on I probably be looking for ways to create a leak. How about opening up the 1/8 tubing (.050) hole feeding the cam gears?
I see 90 PSI @ the traps--60 cruising--no leaks so far.

Well, that could be it too. Too bad I got a girdle on it, makes it kinda hard to swap and get them sealed back up right. The main and rod clearances are on the tight side, and I went back with it that way because the bearings looked brand new when I tore it down. I think I will open up the hole on the oil jet for the cam gear.

Another factor that may be contributing to this problem is the fact that the oil is more restricted to the valvetrain because I am running a solid cam (but the lifters do have the oiled roller tips). Oil gets to the lifter oil galleys freely, and the threaded oil galley plug does not block the passage as it is ground back to ensure this.

Might just be too much volume for this engine.

If that is the case, is bypassing a large amount of the oil bad? I mean, it does bypass to the low pressure side of the pump gears, correct?

 

[tenright]

Geez..mine sees 30 to 40 hot idle all day, and 60 to70 on a WOT run. When I originally asked about this it was even higher...50+ at idle and almost 90 cruising. I cleaned out the relief valve assembly, put in some lighter weight oil and it dropped to where it is now. Most of the replies I got said don't worry about it, had one reply said he had 100 + when he romped on it.....


T

 

[RealestVIN7]

Be thankful you have oil pressure. At idle I have 6 lb. and at full throttle I have 23 lb. (if I'm lucky).

 

[49-blues]

Are you running a turbo saver or oil cooler-could use up some of the pressure, or i installed an adjustable pressure screw fitting on the relief spring- i think i got it from kenne bell, you can adjust the pressure while its running with a set screw. I just put in a 70lb spring on my rebuild-i may want to rethink that.

 

[Black Car]

"I know the guage is close because I checked the resistances of the sending unit at certain pressures and it is right on with what Autometer told me it is supposed to be."

May I suggest still using a mechanical calibrated gauge just to make sure the numbers are correct?
I had a similar problem with my engine. Cold, it would peg the electrical gauge but hot it would drop close to zero.
I had the electrical gauge specially calibrated by the factory or was suppose to be.
Long story short, the gauge read low on the low end and high on the high end. Installed a knowned calibrated mechanical gauge. I have 15-20 psi hot and cold is 80 psi. As the engine warms up, the pressure drops down.
From 20 psi hot the pressure goes up as rpm goes up. WOT is about 70 psi.
Normal cruise (2000 to 2400 rpm) is about 40psi.
All my worrying was for nothing.
Not saying you will find the same thing but, it won't hurt to check.

Gary

 

[Mad_Trbo]

It's pegging the guage. I know the guage is close because I checked the resistances of the sending unit at certain pressures and it is right on with what Autometer told me it is supposed to be. I am running a HV front cover set up with the pump cover on the loose side. All oil passages thoroughly ported and radiused, bearings feed holes opened up to better match feed holes in block etc. Oil pressure is a tick under 25 hot.

I have to run a 40psi relief spring which keeps it at around 70 psi in upper rpms. The relief is not shimmed or blocked, and slides in and out perfectly freely.

Bearing clearances are all at about .0017 with the coating on them.

Pretty strange, I'm stumped.

I would recommend running a mechanical guage right off the block where the stock quage hooks in. If your relief mechanism is working properly you should not have a problem.

 

[STP]

IMO if it's under 100psi WOT, run a good filter (read Wix or Baldwin) and leave it alone....Only thing I would worry about is blowing a filter apart.

 

[RealestVIN7]

Not to hijack this thread but... As some know, I am rebuilding my motor for the 2nd time in a year. My oil pressure cold is around 60-70 lbs. but when it warms up, it stays below 8 lbs. Cruising around it would go up to 23 lbs., but no higher, even under WOT. Now, of course it is knocking, hence the rebuild. It all started a few months ago, but I thought it was just valvetrain noise. What could have caused this? I wasn't hard on it at all.

 

[Mad_Trbo]

Not to hijack this thread but... As some know, I am rebuilding my motor for the 2nd time in a year. My oil pressure cold is around 60-70 lbs. but when it warms up, it stays below 8 lbs. Cruising around it would go up to 23 lbs., but no higher, even under WOT. Now, of course it is knocking, hence the rebuild. It all started a few months ago, but I thought it was just valvetrain noise. What could have caused this? I wasn't hard on it at all.

IMHO improper oil clearances would generate this issue. Measure and measure again.

As far as higher oil pressure goes there are a couple of concerns you may want to be aware of.;

- As previously mentioned a ruptured oil filter.
- Bearing erosion.
- Higher oil temperatures
- HP robber due to the fact that the higher oil pressure requires more work to turn the oil pump.



The person who started this thread may want to look further into the oil relief valve if it is functioning correctly you should not have a worry. There is no way the oil pump can out pump and replace the oil in a manner that exceeds that vavles ability to bleed oil off.

 

[Pronto]

Does the higher pressure affect the seals in the turbo?