Adding Booster Oil Pump?

[Kunery]

My 1970 F-250 (360 V-8) has an oil pressure guage that now barely gets up to the lowest bit of the operating range. I use 20W-50 oil in it. The gauge used to get up to the middle of the operating range, 10 years ago. Mechanics have said the oil pump's worn out, but can't be replaced w/o a complete engine re-build.

Isn't there any way to add an electric pump into the lubrication system somehow to boost the oil pressure back up to where it should be?

(I seem to recall some WW-II aircraft engines had auxilliary electrical oil pumps they'd run before starting, to have proper lubrication from the beginning of cranking the engine, and prevent "dry starts".)

Any suggestions? I feel like a creep, running my old truck into the ground for lack of oil pressure -- but in $ terms it makes no sense to re-build an otherwise OK engine. Thanx.

 

[XS650]

Are you sure it's the pump and not the gauge or sender?

 

[Kunery]

I'm nota certain -- but it used to come up to full operating pressure and over the years the pressure has sagged down further and further, as it would if there was more wear on the pump. Can the gauge be checked for accuracy?

 

[SteveD2]

I don't know anything about your engine...but the oil pump should be easlily replaceable by just dropping the oil pan. A "complete rebuild" would include boring out the cylinders and replacing the pistons and bearings, which have absolutely nothing to do with the oil pump.

 

[terryr]

It's easy enough to change the sender. If that isn't it then the bearings are just getting worn out. As they wear, the oil gets out faster and pressure can't be held. One day it will drop to zero.
This happened with one of my engines. When it went very low I used straight 50W, then a year later it still went to zero (indicated). I drove it 2 months more and it never seized.

 

[Kunery]

Thanks all. I don't hear any clacking of lifters; it uses about a qt per 250 miles, and does blow an impressive blue cloud on starting up -- but not much noticible once its running. I'll try having the sender replaced.

 

[Gary Allan]

quote:

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it uses about a qt per 250 miles, and does blow an impressive blue cloud on starting up -- but not much noticible once its running.

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Okay ..valve seals most likely for the clouds at start up (this can be fixed in the vehicle). Consumption is high ..but given the age of the engine ..totally acceptable assuming that the power and "drivability" are tolerable.

Let us know your results from having the sender changed out.

 

[JohnBrowning]

Kunery, If you blood pressure gets too low you do not replace the blood pressure cuff! Low oil pressure is a symptom. I doubt that a worn out oil pump is the main problem. Their is a far greater chance that you crank and rod bearings are worn out. When the bearings wear out they hemorage oil. It is true a high volume pump might pump enough oil to keep the bearing shells flooded but for how long?

You can change the oil pump easy enough but if the bearings are worn out do not expect to see much of an improvment even with a high flow.

I think I would plasti guage the bearings while I replaceing that pump. I would also make sure you get a high volume oil pump.

 

[Gary Allan]

Do you hear the lifters under any condition?

The mechanic may have meant that you probably need a rebuild ...but as was stated ...you just drop the pan to replace the oil pump. I'm fond of high volume replacements myself (not everyone shares this affection).

For either condition to be true (the oil pump being worn out or the engine needing a rebuild) something else has to be apparent (massive oil consumption, ticking/clacking lifters, rumbling bearings).

If these symptoms do not exist ...the conditions that they would indicate probably don't either.

Replace the sender as others have recommended.

 

[Gary Allan]

John ..think about it. This engine is over 30 years old. Sure it probably needs a rebuild. It's older than many of the members on this board and has seen more dirty combustion than any 50 contemporary engines..but are you going to throw several grand (potentially) into a 34 year old vehicle that isn't "cherry"??? Or bother to go to the extreme of pulling down the pan and unbolting the caps to plastigauge the mains?

He "may" bother to throw in a $55 oil pump if it allows it to function longer. Also consider that it just may be a stuck (scored, varnished, worn out) relief spring that's giving him his low oil pressure. He complains of no "rod knock" or "rumbling" ..nor any valve tap.

But first he's going to replace the sender.

Everything you assert may very well be true ..but let's not all jump on the "doomsday" bandwagon prematurely.

 

[cryptokid]

if it isnt the sender, and is indeed an oil problem, just throw a oversize oil pump on and run the thing for another 50K miles.

a oversize oil pump is a bandaid for the problem, this is true. however, it sure works **** good and is an economical way to extend the engine life out another bunch of miles.

 

[DEWFPO]

How many miles are on the truck?

Have you considered running some auto-rx to clean some of that old 20-50 out?

It might be worth a shot. Might help with the oil consumption issue and might even free up that gauge again. It really depends on the mileage and whether the engine is mechanically worn out or just "gummed up".

DEWFPO

 

[crashz]

Being a huge fan of older trucks of any brand, my advise is to check the actual oil pressure with a mechanical guage (an el cheapo installed underhood will do just fine).

Say your oil pressure is way down:
1) do a compression check
2)If compression is acceptable and relatively even then I would purchase a new high volume oil pump, new rod and main bearings, an oil pan gasket, motor mounts(these are alomst alway shot), front and rear main seals and plenty of AutoRX.
3) Installing the after mentioned parts will bring your oil pressure way up and clean out your rings. Most likely reducing the valve seal leakage too. Your engine will be clean, leak free and will operate like new. Consumption should drop and power will increase.

This is a $500 rebuild that should last for a long time. It is not a complete rebuld though, so don't expect another 30 years!

 

[Shannow]

quote:

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Originally posted by JohnBrowning:
Kunery, If you blood pressure gets too low you do not replace the blood pressure cuff! Low oil pressure is a symptom.

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JB,
but if a doctor takes your blood pressure and diagnoses a heart transplant without further testing, you go see someone else.

In this case, I'd substitute a decent gauge for the pressure transmitter, and see what it says.

If it says low oil pressure, I'd switch to Pennzoil long life, and run it until the engine told me that it needed replacing.

If it had an external oil pump I'd replace it as a matter of course, with a high volume unit.