plsirl

I have a '68 with a '91 302. It has a set of Equus (walmart... I know...) gauges in it that the previous owner installed. One of these gauges is oil pressure, which currently reads around 50-60 before it warms up and a whopping 0 (or this could be in the 5 range, as the dial cant be read perfectly here) after it warms up. It has begun to make what really sounds to me like valve tap; go here if you are really interested in the sound: https://mustangforums.com/m_3582510/tm.htm .

I know the first post here will tell me to get a hand-held oil pressure gauge (I will do this tomorrow, where can a decent one be found?), but is there good reason to distrust the Equus mechanical gauge in the car? I am not experienced with these mechanical gauges; is the line leading to it supposed to be full of oil, or pockets of oil and air as you can see in the attached picture. Do I need to bleed this line or some such thing?

Would worn bearings make this tap tap tap noise? Would you generally suspect that if the oil pressure is indeed that low when warm then the tapping was caused by incorrect oil distribution to the lifters (perhaps causing a collapsed lifter?)? The tap is just as bad when the car is cold and oil pressure reads 50-60. I gave it 10w-40 (instead of my usual 5w-30 and nothing really improved).

What else could be at fault here? I will know more once I test pressure with a different gauge. If an oil pump is going bad would it typically make 50psi cold and 0 psi warm? Could something like the oil pump drive shaft be making the tapping noise?

Lastly, I am fearing the worst (bearings)... if my engine is toast, can anyone recommend a shop in the San Diego / La Jolla area that could help me get a different engine into my car? I currently do not have enough room to complete a full engine swap at home.

For anyone who read this entire thing and does not hate my guts, thanks a ton for your time!




[IMG]local://upfiles/74410/83EC7F6218934F5F80283C5A38E738E8.jpg[/IMG]

turboblast

well I would guess that if your oil pressure really went to 0 psi you would be hearing some real bad noises(bearing knock) Try another gauge. Also the clear plastic tubing from the eng. to the gauge does not always look like solid oil sometimes there are spots where it is clear, this is normal.
The ticking up top could be a sign of low oil pressure. Have you changed the filter also recently?

plsirl

Thanks for the reply.

I changed the oil and filter last week, but completely forgot to check the filter for shavings before I got rid of it.

Any ideas where the best place to grab a manual gauge is? Is there an Autozone loaner or something? I'd hate to buy a new set of Autometer gauges and find the same reading.

67mustang302

Well, I listened to the clip, and even though it's hard to tell from a recording, that doesn't sound like a bearing, it'd be way deeper and "scarrier" sounding if it were. Could be valvetrain, or an exhaust leak(hard to tell in a video clip, and often they sound very much alike). As far as the gauges, Autozone may have a loaner, but you could get a simple one from a test kit of some sort. If you REALLY had 0 psi you'd hear the engine trying to rattle itself to death, you wouldn't have enough oil wedge to float the crank/rods, and it'd smack the crap outta the bearings at rpm or under a load. You'd hear it and cry

Colorado_Mustang

It's likely the bearings are washed out and the hot oil isn't thick enough to maintain pressure. I've had engines like that, and they are surprisingly quiet and well mannered. I'm guessing you are also referring to the pressure at idle. What's the pressure at 2k RPM cold and hot? You could band-aid this fora while with heavier oil (20w-50 or straight 50 weight) while you assembly a new engine.

67mustang302

If your oil pressure is bad from worn bearings you could run a high volume pump, cheaper than a rebuild, between that and heavier oil you could get a fair bit more life out of it. Just make sure you run a hardened oil pump drive shaft

plsirl

You're right, I wasn't too clear, here is a rough breakdown of what my gauge reads:

Cold:
Idle: 25-30psi
2k rpm: 50psi

Warm:
Idle: 0 psi
2k rpm: 0 psi

I am going to Sears in 5 minutes to buy this: http://www.sears.com/sr/javasr/produ...seBVCookie=Yes
to confirm these readings.

plsirl

I am considering my options, would I be able to rebuild the bottom end of this with the engine still in the car? It is a 91 engine with a flipped oil pan to fit my 68 mustang.

Pic:


[IMG]local://upfiles/74410/A7D32F6993CF4FAE8C1496529920D24F.jpg[/IMG]

67mustang302

You could swap out main and rod bearings with the crank still in the engine(that's hard), or partially drop the crank to make it a bit easier. If you don't have a way of getting the engine out, yeah, you can do it with the engine in the car, but without a lift it's a pain, unless someone here has a trick to make it go smoother

Colorado_Mustang

Lift the engine off the mounts and place a chunk of 2x4 between the upper and lower mounts. Make sure you don't hit the firewall, though. Some cars may not have the room. To really do it right, you'll need to pull the tranny, as it is very likely the crank will need some work. It can definitely be done with the engine in the car, but it will bea royal PITA to get the rods back onto the crank properly (make sure to remove the spark plugs). You could remove the heads to help out. This won't be a 1-person job.