I have an '87 302 E150 van, auto tranny.

It suddenly started with this "ticking" noise. Not really loud, but distinct. Not a ping. I don't feel any performance difference. Oil level and oil pressure is good.

Its loudness appears tied solely to RPM, not power level. Revving it in Park
sounds exactly the same as that same RPM going up a hill at full throttle. So I'm ruling out exhaust manifold leaks and pinging. It is not tied to engine temperature, sounds the same warm as cold.

I first figured it had to be the serpentine belt or one of the accessories. Its sound is sort of like a bad spot on the belt clicking/ticking around. However, I pulled the entire belt and started it briefly, the noise is still there. So, it's not the belt and none of the accessories were turning so it's not any of them either.

It's tightly tied to RPM, so it's not something near the engine is loose and just rattling around as the engine runs. If it was a sympathetic rattle it would take a moment to start rattling and take a moment to slow down. And it's a bunch of distinct "ticks" anyways rather than a continuous rattle.

What might I be looking for? How immediate of a problem could this be?
What's the best way to proceed diagnosing it?

 

Possibly a collapsed lifter or loose rocker arm? Without hearing the noise it would be very difficult to diagnose.

 

Oh damn- DAMN!

I checked the dipstick again and it looks like I was only reading oil splashed up there rather than a true level. There's no oil in this damn thing.

I ran this for about 45 min @ 65 mph like this. I added the quart and a half or so of oil I have on hand and ran it a minute but still hear ticking.
How back could this be?

*Vans suck for repairing... anything.

 

It may take a bit for the lifter to pump back up (if it will).

 

Ah just needed to let it run a bit longer. Sounds clean now!

I gotta say, say what you want about the crappy fuel efficiency, but the 302 sure is tough. Come to think of it, this is the second time I've let the oil get low enough for it to become "noisy".

 

got a light or gauge on it?..if so do they work?

I would change the oil and filter asap...........

 

It's just got the normal gauge on it, but with the actual gauge sender, not the sender which puts it in the middle of the scale if above a minimum pressure and switches to zero if below. I don't have numbers for the pressure but I know where it normally is.

Curiously it didn't read anything unusual when the lifters were clicking- and I don't recall it reading anything weird the other time I let it run out either.

 

The top of the engine can starve for oil. It will have pressure, but not enough volume to reach the top (IE cam and lifters.)