Last summer I bought one of my dream cars, a 1966 Toronado.

I got the car at a very good price because the former owner thought the engine was shot.

It runs very strong and the car has about 66,000 miles on it.

When fully warmed up, the oil light flickers at an idle. Idle speed feels right to me. If you just rest your foot on the throttle the light goes out.

I hooked up a mechanical gauge and it reads about 5 psi when hot at idle and goes up to about 35-40 when driving at moderate speeds.

No ticks, taps, or knocks, no funky noises that you would associate with oil starvation.

In order to try to fix this, I ran the car with the oil drained out and added about 6 quarts of kerosene to the crankcase in an effort to flush out any gunk or sludge. This drained out clean.

I then changed the oil and filter and put in some cheap 10-30 and ran it to cleanse and flush out the kerosene.

Changed the oil and filter again and replaced the 10-30 with 20-50 Lucas Hot Rod Hi Zinc oil.

The oil pressure didn't get any higher at a hot idle.

So here are my thoughts and options:

1. Just drive it and don't worry about the 5 psi at idle.

2. Try to find out if these engines had the nylon coated timing gears and could the nylon have crumbled and be blocking the oil pick up.

3. Pull the engine to drop the pan and do a complete inspection of any junk in the pan and Plastigauge the main and rod bearings.

Option 3 is going to be a royal pain. As you know you cannot drop the pan due to the FWD interference.

The timing gear/nylon thing happens to 70's Caddy's which I also collect.

So... Is this common on a 425 with 66K miles?

Is there a magical way to drop the pan with the engine in the car?

Your thoughts and suggestions would be very welcomed.

Thanks,

Brian Rachlin (Brian66Toro)

 

Change oil pressure sender for dash light and see if problem goes away. I believe at 5psi the light should not come on.

 

I tried a different sender with the same result.

Maybe it's dipping below 5, I am not sure. The mechanical gauge looked like it was reading about 5 at the lowest point.

Thanks,

Brian

 

It probably does have nylon timing gear teeth, and a good chance it has shed its teeth or partially. And yes it can get clogged in the oil pump pickup. I dont know Toronados but id be willing to bet the motor will have to be lifted to get the pan off. You can remove the fuel pump and feel the timing chain to see if it had alot of slack, I was able to do this on one olds motor i have. Or if you have an inspection camera, (Harbor Freight) about $65.00, you can look at it from the fuel pump opening. But again 5 psi seems low but it is just idling at that. 35-40 is very good while driving IMO.
Steve

 

5psi at hot idle is slightly low, but still at the very low end of normal (especially if you figure 10psi for every 1,000 RPM).

The idiot light is supposed to go on at about 2.5psi if I recall, so either your gauge is wrong or you've got a couple of bad senders.

What weight oil are you running? Should be 10W30 or 10W40, but if you've got a low pressure problem, 20W50 is good.

Your cruising pressures are fine, which pretty much excludes a clogged pickup.

I would not have run it on just kerosene, but that's water under the bridge.

To check the timing gear, put a wrench on the end of the crank, remove the distributor cap, and move the crank back and forth - there should be essentially no play in the movement of the distributor with regard to the crank.
Feeling for slackness in the fuel pump opening is also helpful.

But mostly, this oil pressure is close to normal - if it ain't broke, don't fix it.

- Eric

 

1. The motor definitely has a plastic cam gear. I always change them by 80,000 miles.

2. The low oil pressure is likely caused by worn bearings.

3. You should probably be using 10W-40, not 10W-30.

 

I'm with Joe on this. I bet if you pull the engine and inspect you will find worn bearings. Might be a pain but if you pull it and do at the least bearings now it might save you a rod or main failure in the future. I had one act like that also. I pulled the engine and found worn bearings. Put a crank kit in it and it is still going strong 40k later. I still refer to the gauges I put in that car as the most expensive gauges I ever bought. but, not having them would have been more expensive. It had no noise and no other issues.

Larry

 

That's what I was expecting to do. So if it's not worn I may be able to get by with standard bearings?

I am running 20-50 Lucas oil in it currently.

It may be a while before I can pull it apart. In the mean time I won't drive it any distances. I don't want to risk hurting the engine.

I'm also working on a 60 Caddy with a seized engine. That's first in line and its sitting on my lift so the olds may have to wait until the summer.

Thanks for the info. Pulling it and checking it is the prudent way to go.

 

What kind of pressures are you getting with that?

- Eric

 

He said his idle PSI didn't change.

 

you may depending on your climate try running straight 40 weight for a try....it does sound like excessive clearance but with not a whole lot of miles on it but you havent owned it since new so previous ownership maintenence is uncertain

 

With 20W50? I guess I missed it.

In that case, I would definitely be careful with it, and plan on hauling the engine out at a convenient time for a good look.

If it's not burning oil and compression is good, there's no need to mess with the rings - just a new set of bearing shells and you'll probably be good.
Wait until you've measured the journals, PlastiGaged it, and seen the bearings before ordering the parts.

- Eric