As a follow-on to my note above, during the decarbon process, the CEL came on 5-10 times during the 3 mile @3,500 RPM drive. Should I disconnect battery and clear for next code scan. CEL light has NOT come on again since decarbon process completed.

John
93 4.0L Aerostar 145k miles

 

could i do the same to my 85 2.3L ?? is it like reving your mtr as you drop in some atf??

 

ATF goes in the auto tranny, not the intake . ATF will attract dirt and grime.

 

my 94 ranger had same problem and lousy gas milage, and one day with out warning it overheated big time. diagnosis the failure was head gasket. Went to my vendor and new rebuild and install. my gas mileage is 20-21mpg on avg. S0, how many mile is on your truck and have noticed, not leak, but having to add antifreeze every so often?
I was like you thinking it fuel, spark, or MAF sensor.

carey

 

I just want to thank everyone for their contributions to this forum. It really helped me quite a bit. Here's my success story that hopefully will help someone else.

I just bought a 1994 Ranger 4.0L with 83,000 miles. It had the classic knock/ping problem during acceleration, and also had idle speed fluctuation during cold starts. The knock would happen during acceleration at medium to high throttle, but when floored it would mysteriously clear up.

I had the engined tuned, de-carboned, and carefully inspected by a good Ford dealer mechanic. We went for test drive after the work was completed and still heard the knock, albeit less frequent. He advised a couple more tanks of gas with the injector cleaner and water remover additives he prescribed, but that did not help.

I read in multiple forums about how a dirty MAF sensor could cause knock on these engines. I advised the mechanic of this, but he said it was fine. I don't think he even inspected it.

After finding a friend at work who had the necessary Torx TR T-20 bit (tamper resistant type with a hole in it), I took the MAF out only to find a black soot-like substance on the intake side of each little metal coil. I carefully cleaned it with some degreaser and some alcohol, put it back together, and viola, NO MORE KNOCK!!!

I believe it was the combination of the de-carbon process, tune-up (plugs and wires), and ultimately the MAF cleaning that solved this knock problem. This is pretty much the same stuff everyone else has talked about in this topic, so I thought I would reinforce that here.

Thanks again.

Matteo
Pompano Beach, FL

 

Welcome to FTE Matteo, glad to hear of your success story!

For others who might wonder about the MAF cleaning procedure and why it can help with pinging, here are a few relevant links:

Connection B/T Dirty MAF and Pinging

Cleaning Your MAF Sensor

 

What Is The Tsb 01-19-7 And Where Can I Find It...?

 

CowboyBilly posted the text of the TSB in his second post in this thread:

https://www.ford-trucks.com/forums/s...78&postcount=2

 

Shoot! I cleaned my MAF without disconnecting the battery and the wiring harness clip. Actually the MAF was clean, and there was no difference after. Should I redo correctly?

John (aka Bozo)
93 4.0 146k miles

 

do you have any pictures...?...I'm not sure where the lower intake would be on a 94 4.0

 

At the top of the Ranger forum is a sticky titled Technical Information. In there is a post (https://www.ford-trucks.com/forums/s...d.php?t=232373) that should help. The lower intake bolts to the heads.

 

Is their a simple way to distinguish the carbon buildup noise from a timing belt tensioner noise? My 2001 4.0 with 100K has a noise starting around 2200 RPM during accell that tends to go away or quiet down after 15 minutes or so, but I am not sure which it is.

 

Well the way I isolated the Combustion Chamber Deposit Interference {CCDI} knock I had on my 99 4.0L pushrod engine, was to use a broom handle as a stethoscope, one end to the suspect area, the other end to my ear. Worked for me!!!!

My knock, which occurs on strtup is not present after the engine warms up for a few minutes.

The CCDI knock I have is a cold mechanical problem, caused by poor prouction tolerance control & combustion chamber deposit build up that adds up to a lack of room between the piston crown & head, in the squish zone, not one of preignition/detionation, that some have.

CCDI sounds like metalic marbles clacking together. I'm told the timing chain tensioner problem on the ohc engine sounds similar, so it should be louder at the front of the engine, around where the chain runs, than around the head next to the spark plugs, where the CCDI would be loudest.

So try the broom handle & see if you can isolate the knock.

 

I bought a '94 ranger w/4.0, 5spd man. one year ago. It has 270,000 kilometers on most everything original. It makes a rattling(pinging) sound when accelerating uphill that dissappears when gas peddle is pushed to the floor. Freinds have told me this is a timing chian that needs to be replaced. It also makes a knocking sound at random times, hot/cold, idling/accelerating, etc. which freinds/mechanics have said is lifters. I've read both threads for engine knock (decarbon) and timing chain rattle. But it sounds like some of the problems talked about in the knocking thread are for the pinging sound (timing chain) that occurs when accelerating uphill. I am a little confused about this. But as for the knocking (carbon), My uncle told me told me that putting ATF (a detergent) in the engine oil a couple days before an oil change will get rid of carbon. If someone could clarify my first problem and give some advice (pros/cons) about the ATF method of decarboning I would appreciate this very much.

 

Welcome to FTE!

First, can you hear the rattling noise when the truck is parked and you rev it up? If so, then you really need to isolate the location of the noise. Use a long-handled screwdriver and place the tip of it on various places on the engine (as well as components) and put your ear up against the handle. The noise will be amplified. Or pick up a mechanics stethoscope from AutoZone, they are real cheap and a good tool to have around. Rattling noises also can be caused by loose components, such as exhaust heat shields. The 4.0L OHV timing chains are not known for this kind of concern.

As for the ATF trick, I would be more concerned with de-carboning the upper engine if you think you might be experiencing spark knock. The procedure to do that can be found in this post:

https://www.ford-trucks.com/forums/s...78&postcount=2