Weekend drive

[Astrowing]

I drove about 150 miles this weekend to get the Tbird to my new workshop and I learned a lot about it. The power is good and it ran 65 to 70 mph effortlessly. Wife followed me and no visible smoke except when I went to full kickdown to merge into some traffic. However, oil pressure is a concern. When cold, I'm seeing 50 psi at road speed. When warmed up it drops to about 35 psi. At idle, it's good when cold, but drops to 10-15 psi at idle. Is this indicative of main bearing wear?

Also, the drivers power window started moving down and I quickly reversed it with the button when I was parking it to leave it. It's like it tripped the breaker, but these breakers don't have a reset correct? The failure was coincidental with trying to operate it. Can someone tell me where the 15 amp breakers are located and do they reset automatically?

[simplyconnected]

Low oil pressure can be caused by LOTS of things. Remember, your oil is picked up off the pan, then it goes through your oil pump, THEN it gets filtered.

Is your pickup screen clogged? This is VERY common with old engines from the days when oil had no detergents.

Since all the junk goes through the pump rotors first, they wear and they imbed little pieces of metal in the rotors. Sloppy, worn out rotors are inefficient, especially at idle speeds.

Bearings can dump oil pressure when they wear, too. It's like a flowing garden hose; when you put your thumb over the end water sprays far because you build pressure. Take your thumb off (lower the resistance), and pressure goes away.

You should see at least 30-psi at idle, and anything over 40 at higher engine rpm's. My Y-Block gives me 40 at idle, and 60 at high rpm's. To me that's a little excessive, but, ok. The oil pump is original, with a rebuild kit from MAC's that cost about twenty bucks.

Your window motors usually have a breaker on the GROUND lead, and I think they are self-resetting. - Dave

[Astrowing]

Thanks! I agree that the oil pump is the first place to start. I read the lubrication theory of operation again, and the oil pump output does go to the oil filter first, which just happens to be where the oil sender is located. The oil pressure you read on your gauges is basically the output from the oil pump then. It does not really given you an indication of downstream pressure in the main bearings or elsewhere. Unless of course the bearings are so bad that they are leaking like everything and the oil pump can't keep up. I'm not hearing any bearing knock at idle, so I think the oil pump/screen is the culprit.

[Astrowing]

Can someone tell where the 15A front window breakers are located? The manual says under the instrument panel, but would like to know where I'm looking. Thanks!

[scumdog]

Thanks! I agree that the oil pump is the first place to start. I read the lubrication theory of operation again, and the oil pump output does go to the oil filter first, which just happens to be where the oil sender is located. The oil pressure you read on your gauges is basically the output from the oil pump then. It does not really given you an indication of downstream pressure in the main bearings or elsewhere. Unless of course the bearings are so bad that they are leaking like everything and the oil pump can't keep up. I'm not hearing any bearing knock at idle, so I think the oil pump/screen is the culprit.

What grade of oil are you using?

[Astrowing]

10-40W is what I've been running. Should I run straight 30W?

[scumdog]

10-40W is what I've been running. Should I run straight 30W?

Hmm, you SHOULD be OK but I use 20-50.

[kuusamon]

Not sure but if I am right the breakers are located behind the kick panels I believe.
greets,

[Dakota Boy]

front window circuit breakers are up inside the dash, one on each side.

[Astrowing]

How high up under the dash are they located? If they trip, are they manually resetable or is it automatic after they cool?

[Anders]

When cold, I'm seeing 50 psi at road speed. When warmed up it drops to about 35 psi. At idle, it's good when cold, but drops to 10-15 psi at idle. Is this indicative of main bearing wear?

Donīt know realy, but itīs telling me that I have less nervous moments if I donīt install a oli pressure guage.....