Ok, this is whats going on: I have a 1992 Ford Aerostar sport 3.0L. Around 10 years ago i replaced the original auto transmission with a manual 5 speed i got out of a cargo Aero i found at the junk yard. Also, ever since i bought that van back in 1998 i could never enjoy the a/c for long. It was always breaking down. Since i used to live up north i didn't care much about the a/c. Many years later i found myself in FL still driving that van but having a hard time dealing with the heat and not having a/c in my van. So i decided to fix it. At this point she's running great! I always try to keep her up to date, tune ups, tires and maintenance in general. She's all i got for now and i love her. So i took the van to a a/c shop and after many complications and $$ she finally has a/c! Some of the complications were vacuum leaks. They fixed some and i fixed some others. Now as far as i know all the HVAC system is working properly.
My problem is that when i got the van back from the shop, now engine is weak, shaking and making a clicking noise that seems to come from the right side of the engine (driver side). Sounds like is coming from inside the valve cover but i can't really tell. Just in case i checked spark plugs, cables, distributor cap, rotor, vacuum lines and found nothing wrong. I did a complete tune up like a year ago.
I have a Ford code reader and did the KOEO test and got two trouble codes:
566 (3-4 shift solenoid circuit failure)
629 (Converter clutch solenoid circuit fault or lock-up solenoid circuit fault)
These two codes been there since i swap transmissions.
After the code reader gave me those two codes, it also gave me some memory codes that i have never gotten before:
121 ( Closed throttle voltage higher or lower than expected)
157 ( Mass air flow sensor fault, low voltage)
212 ( Loss of ignition diagnostic monitor signal/SPOUT circuit grounded)
214 ( Cylinder identification circuit failure)
217 ( DIS fault ignition system - coil #3
332 ( Insufficient EGR flow detected)
338 ( Cars Only - Engine coolant temperature (ECT) lower than expected)
I dont think all those sensors could be bad at the same time. I think something bigger is causing the problem. I thought it was a disconnected vacuum line somewhere since they where working on that at the shop but everything seems in place. Btw, i had to remove the inside engine compartment cover to have access to the rear of the engine and in order to do that i have to unbolt the computer and let it hanging till i was done. I lost one of the nuts and decided to leave it hanging for now til i can get another nut. Does the computer needs to be bolted in place in order to work properly?
Anyway, i dont even know where to start here. I really dont want to start replacing sensors left and right. I did that once and ended up been a disconnected vacuum line. Not the case this time.
Now i have a/c but engine is running terrible. Please help! Any advice will be greatly appreciated!

 

All those sensors showing low voltage indicate an electrical problem, like maybe there's a bad ground. So yes, the metal frame of the EEC needs to be grounded to the chassis. Try that first, and see if the results are better.

 

Ok, i found a nut that fit perfectly the bolts that hold the computer and now is back where it belongs again. I went ahead a cleared those codes from the computers memory, took the van for a ride and pulled the codes again (KOEO). I still get the 566 and 629 (i believe i will always get these two since i changed the tranny) but the other didnt come back. That takes care of that. Thank you for the suggestion about putting back the computer in place.

Engine still running terrible though. I did the KOER scan and i got 111 which i believe it means that it passed. The clicking noise i talked about is more like the sound a person makes when he/she spits. It gets faster when i give it gas. I still believe it comes from inside the valve cover on the driver side. But, Could that noise be coming from the exhaust manifold? If so, why is the engine running so weak and shakes? Cant pin point the origin of the noise and don't know what else to do...

 

If you suspect a vacuum leak, you can verify it with a vacuum gauge. At idle, it should read 16" to 19" Hg.

Not sure about the clicking noise; maybe you can localize it with an engine stethoscope. A ticking valve would have to be in very bad shape to affect how an engine runs. On the other end, exhaust manifold leaks can throw off oxygen reading, so it could make the engine run poorly. You can look for traces of exhaust trails near the sound source.

 

Thank you for your reply. I already tried to look the best as i could around the exhaust manifold area and saw no signs of exhaust trails. But i'm gonna check again with a mirror and try to see all the way around where the exhaust manifold connects the head.
What is so weird is that she was running great before i took her to the shop to get the a/c fixed. Maybe they hit or accidentally disconnected something i haven't seen yet which i doubt since i already check every vacuum line and every electrical harness twice. And so far now, code reader throw no codes.
I love that van and i think its the best looking minivan ever but i do hate one thing about her, and that is the poor access and room around the engine. Cant see the whole engine easily. I want to, someday, put a new engine and even though i have the big jack (don't know the name) to do that kind of job, its useless since i believe in that van the engine comes out through the bottom like a classic VW Beetle.
Anyway, i will keep looking for the source of that noise and if it's in fact related to the engine poor running condition. Thanks again!

**** I was just thinking of something... Around May (5 months ago) i filled up the gas tank and since it's really hot outside and she had no a/c i was using my roommate's car. My van still have a little more than half a tank of that old gas. Could that be the problem? Does gasoline deteriorates in 5 months?
Still, i don't think that explains the noise...and why started to do it overnight.

 

No, I don't think today's gasoline deteriorates in 5 months; they're supposed to have a lot of detergents that prevent gummy build ups.

If there is no electrical problem, I am still suspecting a vacuum leak. Did you check the vacuum tree that's mounted to the rear of the manifold on the driver's side? I've had a line that popped off from a backfire, and it LOOKED like it was still connected, but it was just sitting off to the side of the nipple. This caused the engine to very suddenly run like crap. In my case the check engine light came on; I knew something just happened, so I did not have to run codes.

The engine can be pulled from the front; a couple of members of this forum have done it

 

Hi, yes, actually i just came back from checking the vacuum lines and the tree one more time and i still cant find anything disconnected or broken. I'm gonna have to get me a vacuum gauge, as you suggested earlier, and check everything properly. Still having a hard time been able to see all around the exhaust manifold. I'm taking a break from the heat. Ill get to it in a while again.
Also i wanted to siphon out all the gas just in case but i'm gonna take my chances and just burn it. Like you said, today's gasoline shouldn't deteriorate that fast. But ill feel better when that gas is gone and i put new fresh gas in the tank.
I was looking at the front of the van and you maybe right. Looks like the front frame of the van is held by bolt/screws and rivets that can easily been drilled out in order to remove the engine from the front some day
Meanwhile, i need to make this one run good again.
Thanks again for all that information!
** Ah, one more thing, i dont even remember when was the last time i replaced the PCV valve. Could a bad PCV cause poor engine performance like that? ...and a noise like that?

 

If the PCV valve is not working, it should not cause the engine run poorly. But it does have plastic parts that can break, which will be like a big vacuum leak. It's usually under the upper intake plenum, so kind of hard to reach.

The top piece of plate over the radiator can be pulled off by removing some bolts. Presumably, once you remove that and the radiator and AC condenser, and bumper cover, you should be able to pull the engine out from the front.

 

My PCV valve is on the rear of the right valve cover. I will replace it just in case sometime this week.
Yesterday i was driving the van and turned the radio on and could hear a noise that sounded like a spark hitting ground. The noise got faster as i gave it gas. Dont know if im explaining myself. It was like static from the radio. That happened to me once long time ago and it was a bad spark plug wire. There was a spark coming from one of the wires to ground. Hopefully, this is my situation now. It's been raining every day here. Maybe today i will get the chance to check that.
I will keep reporting...

 

Spark plug wires are all ok, Checked them with a spark tester. No more noise coming from the radio though. Engine still the same. Now i'm getting a continuous memory code: 212-Loss of ignition diagnostic monitor signal/SPOUT circuit grounded. I did my research and apparently the ICM (Ignition control module) could be going bad. I remember seen the guy at the a/c shop connecting and disconnecting the a/c gauges to the accumulator and i remember noticing they had to force the connectors since the accumulator is so close to the inner fender. The thing is that they guy hit a couple of times the ICM that is bolted to the inner fender. I checked it really quick and it looks fine. But thinking on replacing it just in case. Running out of ideas. I think its time to replace every single sensor, one by one, and a good tune up until i find the culprit.

 

This might be part of your problem, once everything dried out, the static issue went away, but you will still have a high resistance in a wire/wires. I would do the old spray bottle test to see which plug wire is grounding itself out.

 

Not sure whats the spray bottle test. How does it work? I may try it :-) Although, Im thinking about just go ahead and take her to a professional. I ve been messing with that van since August. Long story. And im mentally tired. And im not sure i want to start changing parts until i find the one causing the problem.
Thanks a lot for your replies and ideas. I will keep posting updates :-)

 

I think i found out what the noise was. I was looking at the engine while my roommate turned it on and like for 1 to 2 seconds i saw a little of exhaust smoke coming from the exhaust manifold area. So, it definitely has either a hole or it needs a new gasket. There is a gasket between the exhaust manifold and engine head, right?
Still not sure if that's the reason why the engine is running kinda weak and shaky. I will keep posting...

 

Are you sure that is not oil leaking from the valve cover gasket area? You don't usually see these manifolds crack.

And the shaking/weak sounds like a missfire. The spray bottle test is where you take a spray bottle with water in it and spray each wire and see if there is a difference in running and/or arching.

 

I thought the same thing about been oil from the valve cover but shes not leaking. Looks pretty dry and clean around that area. Besides, the smoke is kinda white and only lasts around 1-2 secs after the engine starts. Im gonna try the spray test. Thank you!