So here is the chain of events...A buddy comes by for a ride, I crank it up and let it warm up for a few minutes and all systems are normal. We drive for about 3 miles to the highway and we are at normal operating temp and everything is good to go. Pull on the highway and run it thru the gears but not too hard up to ~70 mph and I smell a faint hint of anti-freeze that lingers for a mile or so then stops. Increased speed to ~90 for a mile + and then slowed down to ~80, glanced at temp gauge and it is normal, checked oil pressure and it's dead ZERO; at which point I freaked and got on the shoulder and immediately shut off the engine just as I heard it start to knock.

So I currently think the thermostat stuck because even though the temp gauge showed <200 degrees the upper radiator hose was pressureized with steam and no liquid best I could tell and some anti freeze was coming from the expansion tank overflow hose, and that maybe I lost the oil pump at the same time for possibly even an unrelated reason. Got it on a flat bed back to the house into the garage for investigation now.

There was no oil on the ground and the level is still full so I ruled out the oil pressure sending unit. I ruled out the gauge because of the knock. I'm guessing it's the oil pump. Any other ideas that I should check first? Current plan is drop the pan for inspection and replace oil pump and pick up. Then address cooling issues.

This is a '70 vert with a big block & 4 speed. Can you drop the pan without removing anything else? First look appeared you might have to remove the cross link rod. If you do, is there anything special about reinstalling it, like alignment issues?

Thanks in advance for suggestions, tips and ideas.

I think I need a beer....

 

It's a good day for a beer.

You're going to need to lower the suspension to get that pan off, and luckily you can do this by unbolting the idler arm from the frame. It all just drops when that's unbolted.

You said your oil level was okay? I know you ruled out the sender but you need to test it. Turn the ignition on, and remove the sender wire. It should go to zero. Touch the wire directly to the block for a ground and it should peg out the reading. If both of these are true then the sender is fine.

Next, pull the valve covers one by one with the engine off and see if there is clean oil pooled in the valleys of the head. Is there fresh oil on the rockers? An engine starved of oil will sling all the old oil off so the rockers will essentially be dry.

If there is fresh oil, start the engine and see if oil is coming out at the rockers. If yes, then the pump is probably fine.

I might also suggest a leak down test and a cylinder pressure test before you drop the pan and replace the oil pump. However, it's possible the pickup is clogged so that's worth looking into.

 

Does your 70 still have the direct gage? (actual oil line) Did you here the lifters ticking-if it has 0 pressure they should tick.If you have an electric gage make sure the wire didnt burn and short on the header.Hook up a $10 direct gage and see if your gage is lying.

 

Did the engine knock or did you hear anything unusual when the PSI was reading zero? If not, the oil pressure may be fine, but the gauge, sender, or wiring to the gauge may have a fault. Or the plastic line to the gauge could have broken. A broken line will leak, but not huge quantities of oil. Maybe your engine is fine. We'll keep our fingers crossed for you.

 

Since you say the engine was knocking I would certainly not start it to test the pump and gauge.
Pull the valve covers, get an oil pump primer tool (Auto Zone loans them for free) and hook it up to a drill and spin it clock wise for a minute or so. If the pump is working you will see oil come out the holes in the top of the push rods.
If you get oil to the rockers, then have someone read the gauge while you spin the pump some more.

This will tell you if the pump and gauge are working.

 

Let's see. 90MPH at zero oil pressure? Chances are, if it started to knock, you dusted it. Pull the pan, check #1 rod bearing first. You'll know.

 

Wrong. Don't start it at all. Check the bearings while you still have a crakshaft. THEY GO FIRST.

 

Ok, my bet is since there was oil and no oil pressure....the pump housing broke. Melling maybe? But....he couldn't be driving like normal without oil pressure unless it's a solid lift cam which at this point would be toast.

 

Have you ever seen a motor pushing a car at 90+ MPH with NO OIL PRESSURE that didn't overheat? Heck, even just low oil pressure going that fast would cause it to overheat. In that car, at 90, that's what...somewhere north of 4000 RPMs? With no oil? It would have overheated, probably seized, with a little extra catastrophic failure to boot.

I also said check under the cover first, with the engine off, to check for fresh oil on the rockers. The rockers, with no oil, would have slung all the pooled oil off and baked the residue. If there is pooled fresh oil then he probably has oil pressure enough to oil the valve train.

 

Hmmm...must not have read the post well enough..did not see where it said it was knocking.
I agree with Bob his idea is the best way to approch this.You need to check the dist. drive anyway.You still need to check the bottom end also.
Clockwise-Right Bob

 

Thanks for all of the input guys! After sleeping on it I'm trying to convince myself that I have 2 seperate problems and I'm about to head to the garage to see what I can learn.

I do have the original tube type sending unit for the oil pressure, not the electric, and there is evidence of a slight leak at the sending unit.

Right after I shut down the engine, I looked thru the oil fill hole in the passenger side valve cover and there was a lot of oil still dripping off everything, but that could be just the timing of when I looked.

I have just about convinced myself the ticking/knocking was heat related and not lubrication related. I know this can be a costly error if I am wrong, so the oil priming tool sounds pretty smart as does the mechanical gauge.

DB-
Your RPM guess is pretty close, it was about 3700.

Thanks again guys!

 

Latest update...

Finally got time to drop the pan tonight. Oil pump drive shaft was snapped at the pump end. Two big chunks of metal from the sides of the drive shaft were in the bottom of the pan and the pump gears were frozen. Pulled the pump apart and found a small metal chunck just big enough to lock the gears. The metal appears to have come from the pick up tube where it swages onto the pump. Someone had pounded it pretty good putting it on is what it looks like to me, but then again it could be some of the metal from the shaft. Everything else appears to be OK but we will soon see.

Oil pump, connecting shaft and nylon seal, rear main seal, & a pan gasket; I am hoping is all it takes and to be running by Sunday.

I'm pretty sure this is not the original block in the car, can someone decode the block numbers for me?

Looks lIke T1IOICRX & 12B55071. It's a 454, 2 bolt main.

 

Given what you just found.. I think you should be pulling it apart for a complete inspection.

 

as someone mentioned, pull the #1 rod cap, also, pull the rear main cap (Thrust) and check the bearings and crank surface for score marks.

 

this is when oil with ZDDP can save the day.
.
had the same snapped shaft in my 289 67, new pump/shaft runs good now.
drove it 2 mi no psi
my theory is this:
why take off the caps? either it knocks w/new pump or it doesn't. if it does, rebuilt it, if it doesn't, drive it.

 

If the bearings are trashed, why waste your time putting it back together if you'll just be tearing it apart again.

 

Sounds awfully familiar to what i did to my motor. Ended up just replacing the whole thing. But if you only need the pump and the knock goes away, I say go for it. Best of luck to you.

 

1st i recommend a frame off resto!
but if u want to drive it, and it doesn't knock why care if they look "trashed?
Of course for a customers' car, i recommend a full rebuild
do u knowhow much time it takes to inspect bearings under the car? for u, i say :
get under there and inspect away. i can throw the pan on and test it before u are halfway done.

 

Why spend a few extra hours inspecting when you can risk ventilating your block? If it were mine I'd sure take the time to inspect the bearings.... but that's just me.

 

A friend of mine had a car that started knocking, so he pulled over and shut it off and had it towed home. After he got it home he decided to start it. I guess he was hoping that it fixed itself while being towed. It broke a connecting rod the second it fired up. Apparantly the bearing that was knocking had siezed to the crank when it cooled down.