-_- New member need help in a big way.

[eDge2k]

Hello all, been a long time lurker but finally have a ford for a change, it seemed like a good idea at the time... about 2 weeks ago, picked up a 2003 sport trac from a friend of mine who works at a dealership, it had a little over 100k on the odo and ran like the most inefficient gas guzzling cloud I've ever owned, it was nice, and I liked everything about it.

Parked it on sunday, had a cold snap monday, out of nowhere, CEL light pops up, trucks idling super rough and wanting to stall, still drives ok over 1k rpms but, still notice a loss of power, scanned for codes, had a couple indicating misfiring, I replaced the plugs and wires as I normally do when I get a new vehicle anyway, didn't help.

I did notice an unusual rattle, a subtle one around 2800rpms, almost sounded like dead cylinder noise, but seems like its coming from both sides of the motor, I can hear a very slight tick of the valves, but again sounds even from one side to the other and wasnt alarmingly loud.... like my motorcycle... which really needs a valve adjustment.

Double tripple checked the plugs were in the correct location, I have spark at all cylinders but here's the kicker, the codes I got were as follows.

Multiple misfire at startup
Misfire on cylinder 1, 2 & 3.
Bank 1 too rich
Bank 2 too lean

I put a MIL on the downstream o2 sensor after this, suspecting maybe the CAT was clogged causing weird readings, no changes, unplugged plugs 1-3 and ran no differently. I'm literally operating on half an engine.

It's been suggested to replace the MAF, o2 sensors, coil pack, fuel injectors etc etc... for the first time I literally feel like I'm shooting in the dark and I dont have a clue where to start, I'm heavily depending on this truck and I have to get it on the road asap, any insight here would help greatly as I cant create new threads yet =\.

If it helps any, below are pics of the live sensor data I got from my scan.

http://i.imgur.com/0miuFNJ.jpg

http://i.imgur.com/mfSFcKf.jpg

http://i.imgur.com/egegZ4L.jpg

http://i.imgur.com/tEiB8dR.jpg

 

[zrxsix3rz]

What kinda engine do you have in it?
Does it only do it when the engine is cold them then quits when the engine gets warm??

I had a problem simular to this happen to me on my 97 explorer with the 4.0l SOHC (NOT SAYING THIS IS THE FIX) but when it was cold out it would idle rough and stall out until it was warm...did a little research and on the 4.0l SOHC the intake maniflod gasket/o-rings would shrink and allow air to pass through and throw a engine code, just like you said I had misfires on cylinders as well! I ended up replacing the intake manifold gaskets and it only took me about 3 hours and $20 and I haven't had the problem since

This is a very common problem with these engines 4.0l doing this

This may not be the fix but I hope to point you in the right direction, I don't know what kind of motor options they had on those so I don't know if you have the 4.0l SOHC

 

[2000StreetRod]

long term fuel trims

I'm not sure I would call someone a friend who sold me a vehicle with significant problems. Anyway, I assume you have the SOHC V6 engine. The long term fuel trims are at opposite extremes. This is often due to the pre-cat O2 sensors being cross wired: Bank 1 O2 sensor connected to Bank 2 and Bank 2 O2 sensor connected to Bank 1. Many people incorrectly assume the driver side is bank 1 and connect the wires wrong. The PCM continues to adjust the LTFT in an attempt to achieve the optimum air/fuel ratio but gets confused because of the incorrect connections. If you don't know the wire colors to check then you can disconnect the bank 2 (driver side) sensor (easiest to access) and the PCM should report bank 2 sensor heater failure. If it reports bank 1 heater failure then you know the wires are crossed.

How many miles are on the odometer? I'm concerned there may be timing chain related issues.

 

[eDge2k]

I'm not sure I would call someone a friend who sold me a vehicle with significant problems. Anyway, I assume you have the SOHC V6 engine. The long term fuel trims are at opposite extremes. This is often due to the pre-cat O2 sensors being cross wired: Bank 1 O2 sensor connected to Bank 2 and Bank 2 O2 sensor connected to Bank 1. Many people incorrectly assume the driver side is bank 1 and connect the wires wrong. The PCM continues to adjust the LTFT in an attempt to achieve the optimum air/fuel ratio but gets confused because of the incorrect connections. If you don't know the wire colors to check then you can disconnect the bank 2 (driver side) sensor (easiest to access) and the PCM should report bank 2 sensor heater failure. If it reports bank 1 heater failure then you know the wires are crossed.

How many miles are on the odometer? I'm concerned there may be timing chain related issues.

1. Our friendship is currently pending, when I picked up the vehicle it was great, no issues what so ever.

2. For the first week and a half, engine had no codes, no MIL no signs of abuse, and over all was in good clean cosmetic condition under the hood and throughout the vehicle. I would assume some indication would have been present if the o2 sensors were reversed at the time of picking it up.

3. I disconnected one of the sensors, it appears to be in the right location.

4. Today, under the advise of the counter clerk and a repair manual, I replaced the idle air control - eh - thingy, no change was present.

5. They only had 1 upstream o2 sensor in stock, i exchanged the IAC for that, I'm waiting for the engine to cool down a bit before cursing and hissy fitting my hands up in there.

**I did notice what smelled like unburnt vapors poofing its way up from the engine when i opened the hood, it wasnt a lot, but I dont know if thats normal, there looked to be some fluidy residue around the connection at the header/midpipe.**

**Also, I can see a tiny bit of gasket material on the rear corner of the intake cover, it's not a lot, and it doesnt appear to be leaking but I cant be 100% positive, for all intents and purpose if that had a failure at the gasket could that cause any of these problems??**

I'll report back when I replace one of the o2s and see if any changes are made. Thanks for the help so far, it's very appreciated. Happy Halloween everyone

 

[eDge2k]

Oh and sorry, Yes I have the v6 4.0L engine, not totally sure if it's the SOHC or not, there isnt a SOHC badge or anything on my intake cover, and I really know nothing about this engine yet sooo.. yeah.. The engine oil dip is on the right side, if that helps lol

 

[2000StreetRod]

IAC valve

1. Our friendship is currently pending, when I picked up the vehicle it was great, no issues what so ever.

2. For the first week and a half, engine had no codes, no MIL no signs of abuse, and over all was in good clean cosmetic condition under the hood and throughout the vehicle. I would assume some indication would have been present if the o2 sensors were reversed at the time of picking it up.

If the battery was disconnected long enough to clear the Keep Alive Memory the fuel trims would be cleared and it would take quite a bit of driving for them to adjust to the extremes.

3. I disconnected one of the sensors, it appears to be in the right location.

How do you know? Did you read the diagnostic trouble code after it was disconnected?

4. Today, under the advise of the counter clerk and a repair manual, I replaced the idle air control - eh - thingy, no change was present.

There is no way a defective IAC valve could cause one bank to be excessively rich and the other bank to be excessively lean.

5. They only had 1 upstream o2 sensor in stock, i exchanged the IAC for that, I'm waiting for the engine to cool down a bit before cursing and hissy fitting my hands up in there.

I'm surprised they would accept it back. Most places won't give credit for returned electrical components. I doubt replacing the O2 sensor will correct anything but I could be wrong.

**I did notice what smelled like unburnt vapors poofing its way up from the engine when i opened the hood, it wasnt a lot, but I dont know if thats normal, there looked to be some fluidy residue around the connection at the header/midpipe.**

You never clarified if you have the V8 or the V6. If you have the V6 I suggest you check the compression. One of the camshaft timing chains may have slipped and the PCM is trying to adjust the air/fuel ratio to make up for lost compression.

**Also, I can see a tiny bit of gasket material on the rear corner of the intake cover, it's not a lot, and it doesnt appear to be leaking but I cant be 100% positive, for all intents and purpose if that had a failure at the gasket could that cause any of these problems??** . . .

Any intake leak will cause a lean condition and the PCM will attempt to compensate until the limits of adjustment are reached. But that wouldn't explain a rich condition.

 

[swshawaii]

ALL 2001-2005 Sport Tracs have the 4.0L SOHC. The early 2001 ST built before 6/24/2000 has the same engine with a slightly different configuration known as the Job 1. Check the commonly failed PCV elbow while you're under there. GL

http://www.explorerforum.com/forums/showthread.php?t=314670

 

[eDge2k]

I clear the codes with my laptop+obd2 dongle before retesting each time, it also allows me to read the percentages of the fuel trim and other sensor data, it takes about 60 seconds after clearing for them to reappear.

I have the v6.

I've spent enough money at this advanced to have a good relationship with me, plus, it had obvious signs it had already been installed before I mounted it.

I looked at the PCV elbow and tubing, from what I can tell it look fine, and actually looks like it's been replaced somewhat recently as its very black and pliable.

 

[2000StreetRod]

failed PCV elbow

ALL 2001-2005 Sport Tracs have the 4.0L SOHC. The early 2001 ST built before 6/24/2000 has the same engine with a slightly different configuration known as the Job 1. Check the commonly failed PCV elbow while you're under there. GL . . .

A failed PCV elbow should result in a lean condition for both banks. Thanks for the engine configuration information. I'm not familiar with the Sport Tracs.

 

[2000StreetRod]

adjusting fuel trims

I clear the codes with my laptop+obd2 dongle before retesting each time, it also allows me to read the percentages of the fuel trim and other sensor data, it takes about 60 seconds after clearing for them to reappear. . .

As I recall, long term fuel trims are not adjusted at engine start if the engine is at idle. The fuel trims from the last time the engine was shut down are used.

 

[eDge2k]

My rpms at idle went up about 80-100 rpms after the o2 replacement on the misfiring side, nothing really major. Both the short and long term trims seem to increase in distance, almost becoming mirror opposites as throttle is increased.

I also have a leaky valve cover gasket I think I found some oil dripping -_-

Fml. I'm leaning more and more towards a timing issue and I know nothing about timing , Im about to do a compression test on as many cylinders as I can before I pass out from exhaustion, I can at least rule that part out, I'll post the results shortly.

 

[2000StreetRod]

broken valve cover?

. . . I also have a leaky valve cover gasket I think I found some oil dripping . . .

The SOHC V6 sometimes will throw a cam follower that breaks the plastic valve cover. Also, sometimes the timing chain will get so loose it "eats" thru the valve cover.

 

[eDge2k]

Well... Explicative. I did a compression test, quadruple checked my plugs were correct and everything, pcv hoses/pipes thingies all look fine, no visual crackage and such. However, cylinders 1-3 have 120psi and cylinders 3-6 have 180psi.

I am by no means a professional, although with a clipboard and pointing I play the part pretty well, but in my booklearnin and such, this is not good.

I'm going to call the guy tomorrow and discuss where this falls under the terms of the warranty, and figure out how have this come out of someones pocket other then my own.

Either way, what would you all suggest the next step to take as far as the repair /further diagnosis, so I can give the illusion I have every idea I know what I'm talking about.

Seriously though, thanks a million for the suggestions and help so far.

 

[2000StreetRod]

slipped timing chain

Well... Explicative. I did a compression test, quadruple checked my plugs were correct and everything, pcv hoses/pipes thingies all look fine, no visual crackage and such. However, cylinders 1-3 have 120psi and cylinders 3-6 have 180psi. . .

I was afraid that the timing chain may have slipped and your compression results confirm that. Your rear (right) guide assembly is probably broken.

That allows enough slack in the chain for it to slip. If it slips enough the pistons will strike the valves.

Since there is still 120 psi in cylinders 1-3 I doubt there is any valve damage. The normal way to replace the rear cassette (guide, chain and sprockets) is to remove the engine. A special timing tool kit is normally required to replace and time the camshaft.

There are probably pieces of the cassette in the oil pan and trapped in the oil pickup screen.

Either way, what would you all suggest the next step to take as far as the repair /further diagnosis, so I can give the illusion I have every idea I know what I'm talking about. . .

Put everything back together and notify the dealer of the compression results.

 

[eDge2k]

Took the truck back today. I should know within a few days what's up and have a definitive answer to this fiasco, they apologized and were glad to take it right away to get it to the mechanics. Fingers crossed it gets resolved quickly. Ill post the end results when Ifind out.

 

[eDge2k]

Forgot to follow up on this, but the problem was indeed a broken timing guide. 2 valves were bent, catalytic converter destroyed. I guess it broke again after the first repair, for whatever reason being used parts or something, it broke when they took it for a test drive so they had to pull the engine twice before it was finally fixed.

Got a number of new engine bolts and this and that, I'm not happy that they cut the cat off and welded on a universal.

I had fork over 400$, half of the cost of repairs as the terms of the warranty it came with, it's been 2 weeks now I think, everything seems to be good. There's an annoying tick from the top of the motor though, I asked the mechanic (because it wasnt doing it before) he said it was some type of check valve in the valve cover if I remember correctly, that after cleaning the noise is louder now. He couldnt tell me specifically what it was, or where exactly, just its function and that it was 30-40$ for the part.

 

[1Aauto]

Welcome to the site