We have a 93 AWD 6 cylinder Aerostar.

The last few days it started to run horrible - engine missing all the time. It's like driving over a "washboard" road, except the road isn't the problem.

My husband crawled underneath to have a look. He says there are 2 cat. converters, and the frontmost one looks as if it has been leaking, there is a lot of white stuff all over it. He looked in a Haynes type repair book, it shows the 2 converters as part of an assembly.

Can just the one converter be replaced, or does the whole assembly have to be replaced? Can the leaking one be welded or repaired somehow? How expensive is this going to be? It will probably have to go to a shop to be fixed, as husband doesn't have a place to work on it or probably the proper tools, either.

The other problem we were having before this happened, is the heater isn't blowing enough air through the vents and outlets. When we set it for heat, you can hear the fan blowing somewhere under the dash, if you turn the different fan speeds you can hear it working just fine, but hardly any air actually comes through into the van. The air conditioning and vent work just fine. Any ideas ?

 

A good independent custom Exhaust & Muffler shop can do anything their customers want from building or replacing 1 piece, to building or replacing or modifying a whole system.

I'm not referring to national franchise here but a good qualified independent shop. I do not know where you are located, but ask around where the custom car folks hang out, or at a cruise night or somebody you know who is into vehicles bigtime.

As for the Air flow from your heater, that is most likely the cause of your bad running engine.

I would guess you have a vacuum line, that normally operates an air blend door inside your heater/A-C plenum chamber. It's come loose or split & is sucking atmosphere (air) into the engine vacuum system rendering the engine clueless and unable to operate correctly.

I bet if you find & fix that vacuum line/hose problem your Aero will straighten up & fly right almost immediately.

With your hood up, look in the front on the passenger side and check to see all lines are connected to something, the one that's not will be your problem line/hose. You may be able to hear it sucking Air with the engine running, if you can't spot it visually.

If the hoses there are all connected there is another place you can check where several Vacuum hoses connect to what is known as a vacuum tree. It is a multi port vacuum connection terminal on the left side (driver side) of the engine in the intake manifold. It's tough to see and tougher to reach. It can be hot in there. If you're poking around when engine's HOT be careful

Let us know how you make out with this. . . .

FBp

 

have the van computer codes read
Autozone and other auto parts store do it for free
or DIY as we do
http://fordfuelinjection.com/?p=13

then please post here to the forum and we can help analyze the engine run problem

unless the cat has a large noticeable hole burned in it or it is plugged, it will not affect the way the engine runs
we find very few cat converter problems with Aeros unless they are damaged or the engine is poorly maintained, burning out the cat.

 

The "white stuff" intrigues me. I don't think the cat is bad either. Are you blowing steam out the tailpipe? Does it smell like raw fuel? What does the oil on the dipstick look like? This "washboard" feel. is it more like the engine misses?

 

I specialize in cats, and I doubt it is the problem as well. They rarely go bad on Aerostars, and when they do, its usually physical damage or from dumping a lot of raw fuel into the exhaust from things like fouled park plugs, bad O2 sensors, or whatnot. I doubt you converter is bad, though it is possible that it could be leaking. I would look at other things wrong, since a bad cat does not cause poor performance and rough running, the problem that causes poor performance and rough running can sure wipe out a cat though.

If needs be, I can get those assemblies, but why. They are easy to replace with regular weld in universals and any muffler shop can do it. Its one of the easier vehicles to work on as far as exhaust is concerned. I would very much doubt the converter is leaking, because if it was leaking, it would sound like a ricer on steroids.

The white stuff could very easily be antifreeze, it turns into a white powder when it burns. Could be related to your heater problem.

 

Thanks for all the replies so far...

He has checked all the visible vacuum hoses, and the vacuum tree, they all seem OK. He says there are 2 vacuum lines that he can access by taking out the glove compartment, that go underneath and out toward the firewall. He says if he pulls them straight, the heater works. But, the van still runs rough.
He said when he was underneath the van, he can feel exhaust coming out around that first converter closest to the front.
He says the roughness is from the engine missing. It isn't too bad when van is in park and idling, but when it is in drive, it runs awful, kind of a rumbling, rough feel as described above. He had me punch down the accelerator to see if it would break loose, but it didn't, and would hardly accelerate at all. Also, this whole thing started suddenly. On Thursday it ran fine, on Friday, it was bad.

 

If it runs fine in park and idle, you may have a transmission problem. Will the engine rev fine in idle? A bad MAF sensor will cause the exact symptoms you are describing. It can go suddenly too. Any codes? If so, please post them here.

 

concerning heater problem, three years ago i had a similar one in my 3,0L, hard to fix!!! In fact on the heater the vaccum line run in 3 separate plastic tubings through the heater housing; after removing the fan i've seen that 3 lines where cut inside; why? i don't know, perhaps the recycling door scratched them... or a mouse...
Repairing them without removing heater housing is a gynecological nightmare, barely worse than changing spark plugs. The symptom was that all is working, fan, heat, but the dashboard doors don't operate when moving the selector.

 

Maybe you really do have a bad cat. I had one plug up at around 30K on an '82 El Camino. How hard is it to disconnect it at the inlet and wire it aside for a test drive? It would be loud but it wouldn't take long to run the test.

 

Without "D-Codes" or "a thread of D-Codes", we are just Guessing based on general combined
experiences from our varied pasts.

If nothing else "D" codes indicate what we should discount/ disregard. They'd also head us in a
general direction for further, more accurate & plausible "DP's" (Diagnostic Prognastications).

Even a read from national franchiser who Diagnosis's to sell parts would help.

Otherwise we're spinning our wheels & watches here

FBp

 

Hello gentlemen -

I didn't forget about this, the Aero is sittin' in the driveway with the front wheels up on ramps..... just waiting for my hubby to get it somewhere and have the codes read. When he does, I will post the info here. Hopefully, it will be soon!