Hey everyone. I have a 1994 E350 Club Wagon with the 460. It has about 156k miles on it and I have had it for about 8 months.

While driving it around town, there are no issues and it runs fine. But once on the freeway, after about 10 minutes of driving at speed, it starts to ping at part throttle.

Power seems OK, shifting down on a hill eliminates the pinging for the most part.

Gauge is not showing any over heating at all. Once you get off the freeway, the pinging goes away after about 5 minutes.

There are no CEL's. I haven't run checked for codes not tiggering the CEL.

So far I have just dropped a bottle of Techron into the tank and that is it.

I have done some searches but nothing similar.

Has anyone seen this before?

I thought it might be the E4OD overheating at speed. Fluid level looks OK and not burnt/smelling funny. (Crazy but it is hard to find info on checking this transmission fluid level.)

Any ideas would be great! Thanks

 

Hi Shocker,
sounds like the fuel trim might be causing a lean fuel mix? Bad O2 sensor, maybe. They won't usually toss a CEL unless they are dead.

Other causes could be spark timing, too much spark advance.

Seasonal changes in gas formulas can cause this, too. jim

 

Ok that makes sense. O2 sensor and maybe the fuel filter as well.

I do know that the previous owner replaced the distributor with a new one. It also has a new radiator as well.

The formula's here in WA State don't change as we have the 90/10 all year long.

 

Bump for help!

 

did you try running super ? could also be the egr valve is stuck closed .Ckeck the timing if the distributor was replaced the timing might be off

 

I have almost a full tank of regular unleaded, but I will start adding 92 octane when it gets down to 3/4 tank.

The van was running just fine up until a few weeks ago. I guess it is possible that the distributor hold down came loose. I will check it and the EGR.

 

Ok, so I have replaced the EGR, the EGR vacuum controller, PCV valve and the O2 sensor.

Things remain the same. It does seem to take a few minutes longer for the trouble to start on the freeway, but it starts up nonetheless.

I did forget to mention that there is also some kind of ticking noise like a sewing machine that speeds up with RPM. It was doing that before as well.

Where do I go from here?

 

I may have missed it but have you done a timing check for base timing? jim

 

Can you visually inspect the internal condition of the catalytic converter(s)?

Is the ticking an exhaust leak at the manifolds?

If so, it's possible the system is sucking air before the 02s so the ECU sees a lean condition and adds fuel to the mixture to compensate. This fuel rich mixture then damages the cats. Purely hypothetical from me...

Another possible path, is it possible to check fuel pressure at the time of "failure"?

 

Hey Jim, I haven't checked the base timing. I didn't think of that as it was running just fine a few weeks before. I can't find the procedure to check the timing. I assume you have to pull some sensors to keep the ECU from interfering?

JB - I know there is a small exhaust leak upon start up which usually goes away after about 3 minutes of warming up.

The ticking starts after about 8 minutes of driving at freeway speeds. It get progressively worse until it is pretty loud. By then it is pinging under partial load. Slight load just he ticking, heavy load just the ticking, partial throttle it will ping. Not super heavy.

I can try and check the fuel pressure, but I don't have a way to do it.

The cats look OK upon visual inspection. I tapped on it and it sounds normal (no rattly parts). No weird discolorations to show overheating.