Oil Pressure

Good morning V8 Buick. This past weekend I finally got all my gauges installed. I'm happy with all the readings except the oil pressure. I drove around for about 2 hours got it nice and hot then took the pic above, at neutral idle and it shows 5psi. In drive with the brake on its at 2.5psi.

I know this question has been asked probably a million times already, but I need some advice on oil pressure. From what I've read here, I should have around 8psi minimum at idle and an additional 10psi per 1000rpm.

Well I'm not getting close to that. At 2000rpm steady I'm getting about 12.5psi. At 3000rpm I'm getting 17.5psi.

Cold start up I'm at 40psi.

I've had the car for 3 years now and have been driving it like this, not knowing my exact pressure. Now that I know for sure, I'm concerned.

Where should I start? TA stock oil pump, or hi pressure? Booster plate? Do I need to replace the stock timing cover?

Thanks!

 

Do you know the real mileage of the engine? There are reasons this could be happening, some expensive, time-consuming and not fun). I would start the route you alluded to with the oil pump. I would pull the timing cover and look at the gears, gear pocket and the oil filter cover. The booster plate will def help if your issue is in the cover/pump.
I run a booster plate, blueprints gears from American Machine and Performance, adjustable pressure regulator from TA And a new filter cover from them.

Hopefully you find a problem there before you are forced to go in the engine. Good luck.

 

lotsa variables here... is that a mechanical or electric gage? Mechanical; Id swap another gage for comps. Electric, if you know the values of the sender, check that with an ohmmeter. The pumps another story; been in there yet? Might be as simple as a stuck open relief valve, or a collapsed spring on same. FWIW, I have a used but new looking T/A booster plate and gears from mine as a take out that are available. PM me if you care to chat about that. ws

 

I also think that with 2.5 psi at hot idle the hydraulic lifters would start clicking. You need at least enough pressure to keep the lifters pumped up to overcome valve spring pressure and with the rocker arm ratio, thats 1.5 X the spring pressure. ws

 

Engine has 84k (i believe to be original) miles. I was told by the seller that it was rebuilt in 2004 with a mild crane cam and lifters.

Gauges are electric. I have not been in the pump at all yet. I get occasional lifter/valve noise at cold start, but it stops after about 2-3 seconds.

Cranking the engine (cold) does not read on the gauge. After startup when oil is flowing (like I said about 2-3 seconds) I see pressure and no noise.

 

Don't go into the oil pump yet. Verify pressure with a mechanical gauge. If you get the same readings then I would look at the pump. Once there you have few options. If you have low pressure because the end clearance is too wide, then you can fix that easily. If the end clearance is good, suspect main bearing clearance is wide. If that is the case, you can run a high volume pump. Wide main clearance will be a large enough bleed that you shouldn't have any HV pump issues that others have had. I fixed up a local guy with a HV pump and it's still going strong. I would only run the KB style of booster plate, the Melling doesn't do much other than a new wear surface. PM me if you like and we can discuss.

 

PS Your voltage looks very high to me.

 

I replaced the original 55a alt with a 105a Jamie built. Would that make a difference?

Also a new optima battery.

 

Thanks for the link Larry, I was looking for that one!

Does it matter if rpm/pressure is checked in neutral vs. under load?

 

Yes, that is the difference. Maybe your gauge is off also. Typically 15 in my opinion is high for these old cars. Maybe someone else will chime in. The style of alternator you installed typically puts out more voltage at lower speed than what you had originally.

Let us know where you end up on your pressure. If you need parts, I have some and we are local.

 

Thanks Rob

I'll have to get it hot again this weekend and put a mech. oil gauge on it.

At least I have one gauge (temp) out of 3 that looks normal!

 

I was assuming mine would read the same somewhere in the middle between 14 and 15. I'll put a meter on it and check if the gauge is reading correctly.

If the gauge is reading correct do I need to do anything or just leave where its at?

 

H/V pump stuff is spoken for... ws

 

OK Kevin,
I have to ask what the knob between oil & temp gauges does?

 

That's a back light dimmer switch. The one in the upper left is on/off.

 

No worries Bill thanks for the offer!