Another 5.0L Miss Thread

[Cali' Explorer]

Hey all-
Well, after a little over 3 years of faithful service, my X has finally decided to cause me some problems.

The Background:
Starting about 2 months ago (mid to end of February), I noticed under WOT when the X would shift, I was getting a slight pop from my exhaust. Almost like a backfire, but no where near loud enough. It only happened under WOT as it shifted, so I didn't think much of it.

Flash forward to 2 weeks ago (April 7th - 8th). I took a trip down to my families. Part of the trip was going to include an Oil Change and Coolant/Thermostat change for the X. I noticed when leaving (as did my Fiance, which really indicates how noticeable the issue is) that at WOT and near WOT, up around 4k+ RPM that the I was getting little pops like before, but intermittently from this point on. No problems below 4k RPM, and no problems if at at approximately 1/2 throttle or less... interesting.

Flash forward once more to last week (April 14th). On my way back from a meeting I filled up with gas for a trip to my families the following day. Tank was 1/2 full and I just topped it off. After leaving the gas station I noticed that I was getting the popping with a slight surge at anything over 1/2 throttle. I took a 3 minute trip over to the bank to deposit my paycheck. Upon leaving and getting back into the car (maybe 10 minutes later), had a hard time starting the explorer, and when I finally did, it seemed to be missing slightly at idle. Between the bank and home (approximately 1 1/2 miles) the X went from running OK to running horribly. Starting sputtering and shaking at lights, popping under any load, and constantly feeling like it was ready to stall at any moment.


That's where I am at now. I have driven the car 3 times since then out of necessity. All trips were less than 4 miles (2 miles each way). And each time, the X has had the last results, barely running, sputtering, popping under acceleration, etc...


Things I have Checked:
- A vacuum test this morning noted Vacuum steady at 20.5 at warm idle, with a slight fluctuation from 20.5 to 20 every once and while. The drop corresponded with a "sucking" sound from under the hood. This may have been the IAC Valve increased the RPM slightly. Other than that, its rock steady (even with the engine missing).

- Fuel Pressure test was done by Pep Boys (I originally thought it was an FPR or Fuel Pump, glad I had them test it first). Fuel pressure was 32 PSI at idle, 40 PSI at WOT and 40 PSI with the vacuum hose removed. There was no indication of any fuel in the FPR Vacuum hose line.

- So far, there has been no CEL thrown. We'll see if that continues.


Next Steps:
- Compression test (just received the compression tester last night). I'm hoping this will shed some light. Depending on what this returns, I will most likely next have to do a leak down test.

- OBD-2 Test. I am planning on ordering an AutoTap setup with the Enhanced Ford data to see what's going on with all the sensors (and more importantly, what the computer thinks is going on).


Things Replaced Recently:
- Lifters & Upper Gaskets: Replaced about 25k ago by Ford. 3 of the Lifters had collapsed and I had an extended warranty, so Ford replaced these. I was a bit concerned as they quoted me 3 days minimum time and had the job done in approximately 1 done. Although this was the 10th time I had taken it to them for the same issue.
- Ignition Coils: Replaced with Accel coils about 15k miles ago.
- Spark Plugs: Replaced with MotorCraft Double Platinums about 15k miles ago.
- Spark Plug Wires: Replaced with Borg Warner Spark Plug Wires about 15k miles ago. I have ordered a replacement set of Accel Spark Plug Wires and will be replacing them when I do the Compression Check. Similarly, I will check the condition of the Spark Plugs at this time as well.
- Thermostat: Replaced about 500 miles ago with a Prestone "OEM" thermostat. Coolant was changed at the same time. Coolant had some mineral deposits in it. This was replaced before this when the Lifters were replaced (at least, I HOPE they point new Coolant in).
- Oil & Filter: Replaced about 500 miles ago with Mobil 1 Oil and a Motorcraft filter. The explorer burns little if any oil (burned about 1/2 - 3/4 of a quart over 7k miles). Although, up until now, it has never burned ANY oil, so this might be a point of interest.


My explorer currently has just under 105,000 miles on it. I have noticed a steady drop in performance since about 80 - 85k miles. It had 60k miles on it when I bought it used just over 3 years ago.

Progress will be slow overall for 2 reasons. First, it is the end of my school semester which means lots of projects and very little work, which means money is tight for the next month or so. Secondly, I live in an apartment complex which means I can't just tear my engine down in the parking lot. Where and how I will get the work done, I'm not 100% sure yet, but there are a couple of places I can do it if the need arises.

Any suggestions, information would be greatly appreciated. I am rereading V8BoatBuilders thread with similar issues and doing some side reasearch as well. Overally, my main reason for posting is to hopefully be of help to others with similar issues in the future.

 

[Turdle]

It really sounds ignition related to me, but no codes?
Have you watched the engine run in the dark to look for arcing?
watch aross coilpacks, and plug boots

 

[Cali' Explorer]

jtsmith-
Now that you mention it, I have thought on and off about it being ignition related. There are no codes being thrown at all. I haven't actually had it running with the hood up at night.

I will also do this simple test tonight and see what it turns up (sometimes the simplest tests are the best).

 

[TheJMan]

I had a similar problem with my 5.0L. It started misfiring a couple of days after I put on a set of brand new wires, plugs, and headers. Well, I guess I didn't do the best job at routing the wires and one of them was resting on the header . It did have the heat sock over it, but even with the ceramic coating and the heat sock, it was still hot enough to burn right through the sock.

No CEL at all during the misfire issue. When I pulled the plugs I noticed that the cylinder that had the burnt wire also had a plug with some rusty deposits all over it.

My advice, pull the plugs to see if you can find which cylinder(s) is causing the problem and work from there.

 

[Cali' Explorer]

Well, I may have found the problem, but I have to wait until tomorrow for sure.

When I went out last night to check for sparking at dark, boy was I surprised. It took me a while to let me eyes adjust, but once they did, I say at least 6 places in one wire alone where it was arcing to other wires, etc... Similarly, I found 2 wires that were arcing against each other despite being almost 3/4" apart... crazy.

I already have some Accel wires on order that will be here Friday, so I will go ahead and replace the Plug Wires (and check the condition of all the plugs while I'm at it) and see what happens.

If this resolves the problem, I think I will just order a set of Motorcraft wires and keep the Accels as good test spares. I am horribly dissapointed in Borg Warner, their wires barely lasted 15k. But, maybe that has to do with the Waste Spark system on the Explorer... perhaps this is also why nothing works as best as Ford parts for the ignition? Time will tell.

 

[Cali' Explorer]

Ohh, one other thing I forgot to mention. After playing with the wires last night to confirm they were arcing, I got in the cab and low and behold, the CEL finally came on. It must have been missing just enough to cause the car to run like trash, but not to set off the CEL.

Also, Glacier is being kind enough to let me borrow an OBD-2 Diagnostic System for a couple of days to clear my codes and check out what's going on in the engine. I will go ahead and run some tests anyways just to ensure that all is happy according to the computer.

I'll keep you posted.

 

[Turdle]

Yeah, I honestly tried hard to get a set of nice colored wires to work.
I finally got a set of motorcraft, or maybe it is auto lite, from orielly
They will list 2 sets, priced way apart, I bought the least expensive.
they perform great for me
I couldn't visually tell a difference between the 125.00 motorcraft, and 75.00 motorcraft fyi
I think you got it

 

[Cali' Explorer]

Well, I got the OBD-II scanner from Glacier yesterday. Great guy by the way, a huge assett to this forum.

Anywho, I hooked up the scanner and low and behold, 4 trouble codes. 2 were Cylinder Misfires (Cylinders 4 and 7), and the other two were unreadable. They listed as codes P0000 on the scanner. I'm assuming these are Ford Extended data and that they are still related to the Misfires. So, I will go ahead and swap in the Accels and if all is kosher, I will go buy some Motorcrafts and keep the Accels for test spares (Ford Parts Network has the Motorcraft wires for $60.00, that's not too bad).

Also, while I had the scanner hooked up, I decided to take a look at what else was going on in the engine. Everything seemed more or less ok. TPS was at 16.5% (Which from V8's thread appears to be right), IAT was at 111 degrees, but I was parked and it was relatively hot. Fuel Trims were all within 0 - 5%. The only thing a little out was the right banks O2 sensors kept heavily fluctuating, but I have a feeling this has to do with 1/4 of the cylinders not firring and burning up the fuel. Plus, I think that it is more like 4 cyliners not firing, just that only 2 were bad enough to trip the code.

I will be swapping out the wires tomorrow (weather permitting and assuming the new one's come today), and we'll see where it goes.

 

[Cali' Explorer]

Well, just another small update.

I swapped out the spark plug wires with the accel units. I went through and was very careful to direct all the wires away from anything they might ground against and each other. Also paying close attention to wire seperators. Inevitably, there's always one or two wires that seem way too short, and one or two that seem way to long, haha. Anyways, all said and done, she idles and is driveable again. One thing taken care of.

The other issue is that I still have the slight popping in the upper RPM range, although not as pronouned. I still get around 1 to 3 pops under acceleration between 4K and the shift point at WOT in each gear (well, in gears 1 and 2, havent' taken it on the freeway yet).

Also, when I swapped out the plug wires, I checked all the Spark Plugs themselves. All but 2 (on opposite sides of the engine) had silver spots on the insulator, and what appeared to be slight blistering (tiny, melted metal looking bubbles) on the insulator and slightly on the electrode tip, arm, and some around the outer edge of the outer part of the plug (like, where the threads are, but on the inside). If looking in a Haynes manual, it looks the most like the "Too Hot" scenario, but the Electrode arm looks almost brand new still, just the insulator looks off (and not as bad as in the picture). These plugs were replaced 15k and are Motorcraft Doulbe Platinums, so that should be all good.

I think my next step is going to be to get and use some OBD-2 Software with datalogging ability, hook it up and take a few drives with the X and see what it returns. At idle, all the fuel trims and what not seemed well within spec, but its possible everything is going out of whack at higher RPM or under heavier accelaration.

Any other suggestions are as always greatly appreciated though.

 

[Lt1Fiero]

One More Thing You Might Think About Is Carbon Build Up. The 5.0 Are BAD For That. I Own Several 5.0 AWD and Work In A Repair Shop The Sees Alot Of 5.0 X's. Do A Seafoam Treatment. Or HAve A Shop Do A BG Induction Clean. WOrks Great.

 

[Cali' Explorer]

Well, in light of your Carbon build up mention, I remembered I had bought some Seafoam to do just that and never got the chance to do it. Two days ago I went out and did a seafoam treatment, using about 3/4 of the bottle. Got lots of smoke and what not, but after all was said and done, there doesn't appear to be an improvement whatsoever.

Another note: I did just realize that my X has started burning oil. Its not TERRIBLE, but enough that I noticed. Normally, I can go 5K miles and not burn a drop of oil. This last oil change, I checked the oil before changing it and it was approximately 3/4 of a quart low. I know engines with 100k can sometimes burn oil, but knowing that at the last oil change before it didn't burn a drop, this seems suspect to me. I'm not keeping a close eye on the Oil level to see where it goes.

Also, I've continued to smell a noticeable Fuel and Oil smell from the X. Normally, I get a fuel smell while warming up, and once warmed she smells clean as a whistle. The last couple of days I've noticed that it if I give the engine a quick rev, I get a noticeable fuel and oil smell even after the X is all warmed up properly. Looking more and more like something a bit deeper. But, only more tests will tell for sure.

 

[Bill MacLeod]

If you still have the OEM coil packs, put them back on and see if this makes a difference.

Fuel filter been changed recently?

 

[Cali' Explorer]

I do still have the OEM packs, so I will probably swap them in either this weekend or next depending on time.

For the fuel filter, it was replaced at 90K (so 15K ago).

Its running ok for now, so I am holding off as much as possible on diagnosis until Finals are over, no reason stressing about one more thing at this point.

 

[Turdle]

I am usisng MSD coilpacks, a friend of mine is using the accell packs. I noticed while installing the accell packs, thr spark plug wires go on in a different order, aren't in same position as stock.
Did you notice that?

 

[410Fortune]

notice? hahaha I hope so....


Where is your 3/4 quart of oil going now? Are you sure its not ending up on the ground?
3/4 of a quart after 5K when you didnt losse a drop previously = something to look into. Either filter or plug is leaking or ???? PCV?

 

[Papa]

Well, in light of your Carbon build up mention, I remembered I had bought some Seafoam to do just that and never got the chance to do it. Two days ago I went out and did a seafoam treatment, using about 3/4 of the bottle. Got lots of smoke and what not, but after all was said and done, there doesn't appear to be an improvement whatsoever.

Another note: I did just realize that my X has started burning oil. Its not TERRIBLE, but enough that I noticed. Normally, I can go 5K miles and not burn a drop of oil. This last oil change, I checked the oil before changing it and it was approximately 3/4 of a quart low. I know engines with 100k can sometimes burn oil, but knowing that at the last oil change before it didn't burn a drop, this seems suspect to me. I'm not keeping a close eye on the Oil level to see where it goes.

Also, I've continued to smell a noticeable Fuel and Oil smell from the X. Normally, I get a fuel smell while warming up, and once warmed she smells clean as a whistle. The last couple of days I've noticed that it if I give the engine a quick rev, I get a noticeable fuel and oil smell even after the X is all warmed up properly. Looking more and more like something a bit deeper. But, only more tests will tell for sure.

Time to check your plugs for oil contamination.

 

[Cali' Explorer]

Ok, for the Accel Coil Packs. I don't know if your friend has the V8 with (2) 4 Tower packs or a V6 with (1) 6 Tower pack, but with my Accel Coil Packs, there were no instructions saying to change the order of spark plug wires. The other thing, its not driving like it would if they were out of order. In the lower RPM range its pretty much fine, and when I went from the OEM to Accel units, there was no change in how the X drive whatsoever. Although, if you have information on how the Order changes with the Accel units, I can definitely take a look at it.

As for the oil, I'm absolutely sure the X is not leaking the oil on the ground or out any other orifice. The outside of my X may be dirty, but when it starts piddling on the ground, I notice it. As of yet, the X has yet to leave a drop of oil on the ground. It seems like it may be starting to burn the oil. While I'm not getting smoke out of the exhaust that's noticeable, I have started noticing a slight burnt oil smell out of the exhaust when I rev the engine that was never present before.

Similarly, the spark plugs are not contaminated as of when I checked them 2 weeks ago when I changed all the spark plug wires. Although... there was 1 spark plug I didn't pull because it was huge pain to reach and it was starting to get dark. May have to go back and check that one.

 

[Cali' Explorer]

Well, a lot of progress was made this weekend.

I went down to the Bay Area this weekend to defer to the professionals (My Mechanic friend). He always gets a kick out of working on Ford's (Or, is it that he likes to kick Ford's instead of working on them?). Anywho... we did some diagnostics on the engine.

First thing we checked was all timing/fuel/ignition related sensors. MAF, IAT, TPS, Camshaft PS, Crank PS, Advancing module, the like. All tested good and fine. Next we basically pulled a number of them in different orders trying to see if one order was better or worse then another. His initial thinking was that it was timing related since it only happens above 4k. Similarly, it was acting like the timing was getting really retarded.

His last test was to toss in a known good ECM from another Explorer. Although he said that a leakdown test may have shown a fair amount, he did say that if it were the valve guides only that were going bad (which was my premise), a leak down wouldn't necessarily show up as the valves may seat properly, but Enter/Exit at funky angles due to the Guides and seals being shot.

His solution, Rip 'er out. We pulled all the upper intake stuff first and then checked the driver side cylinders. He basically checked all the valves, seats, etc... for too much slop and side play. After checking 3 it looked like we had a winner. So we started tearing out the rest of Intake etc.

Since the X is in the Bay Area at my Fiances parents house, and I had to come back to Sacramento for Work, it sadly isn't finished yet (The Explorer fought me nail and tooth as I yanked her parts off). So far, we have the headers off (Passenger side Collector bolts are a HUGE pain BTW), the upper and lower intake off, and one Cylinder head basically out (Bolts are out, but decided not to pull it until after Memorial day weekend).

So, at this point, I'm waiting for 2 weeks until I can get down to the Bay Area to finish tearing out the Cylinder Heads. At that point, my friend's going to take them over to his Cylinder Head guy to have the crack and compression tested to make sure all is good. And assuming he gives the go ahead, we're going to have him rebuild them. Depending on what he comes back with, the prices, etc, I think I'm going to have a whole head job.... new valves, seals, etc... Although this might be overkill, I figure I want to get at least another 100k out of this Explorer, so its a small price to pay. Now, if he says its a total waste of time... I may change my tune, but that's what I'm planning for at this point.

I'll keep you all posted as things progress further.

 

[Cali' Explorer]

Ohh, also, on another note. As we gutted the ignition system, I had my friend check the plus as well to confirm what I was seeing. Numbers 1, 2, 7, & 8 all had fair Oil Contamination. What was weirder still though was that they were also giving a "Too Hot" look. When we pulled the Lower Intake off, it was pretty clear which cylinders were having problems.

Also, we determined that the popping I was getting which sounded so off was actually on the intake valves. Looks like they were getting stuck open at High RPM and allowing the exaust and combustions strokes to pop back through the inkate. Once the car was not in motion, and there was someone revving the engine and me on the outside, it was much more apparent.

Considering the decline in performance over the last 10 - 15k miles, I'm hoping this was the only problem, but only time will tell.

 

[Cali' Explorer]

Well, just another short update (sorry, no pics).

Cylinder Head Removal:
Got the Cylinder heads all of this weekend. Overally a simple process since we had all the top end off already. There are 3 key things to watch for at this stage of the game.

1. Make sure to get all (3) bolts that go through the Accesory Brackets to the Cylinder Heads, I only got off 2 at first and couldn't figure out why they weren't coming off.

2. Make sure to disconnect the bolt from the Transmission dipstick on the passenger Side Cylinder Head. I believe it takes a 1/2" or 5/8" socket to get this off.

3. Make sure to pull the wiring harness routing patch from the Drivers Side Cylinder Head. It looks like the wires that run down the pipes to the O2 Sensors are attached to the back, outside of the Drivers Side Cylinder head and provided about 5 minutes of pain for me. The problem was, once the cord was stretched, the "Press fit" plastic one way dealy wouldn't come out, so I pulled it from the Wiriing harness instead.

* One note on the Cylinder Heads; these Heads are EXTREMELY heavy. If possible, have a friend with you to help you. I was able to get them out myself, but I have considerable mass to throw around which helped me get them out. I would say each one is about 40 lbs. and you have to twist them at some awkward angles to get them around the wiring harness.

** One other suggestion if you tackle this project, plan to remove the Cooling Fan and shroud. I opted not to remove this and spent about 1/2 hour trying to remove one of the Accessory Bracket Bolts from the Drivers side. Had I spent 10 minutes to remove the fan and shroud, I could have avoided this.

Current Status:
I am now waiting to hear back from the Machine Shop on whether or not there is anything else wrong with the heads. I think I caught it soon enough that not too much is damaged, but only the machinist can tell me for sure.


Next Steps:
If all is well with the heads, I am planning to replace the Rockers and Pushrods with new FMS Roller Gear. While this is a costly endeavor at this stage, I think it will pay off in the long run. I believe the reason this has happened in the first place is from the amount of up/down load put on the Valves from the stock stamped rockers. My hope is that by replacing them with Roller Rockers, it will increase the life of the heads substantially (Plus, its just cool). In addition, I will also be ordering FMS Head Bolts, Shims and Dowels at the same time. I will have a properly done up Ford then.

I also brought my Upper intake stuff home with me for clean up while I am waiting. I plan to get the Gaskets all cleaned off, surfaces as well. Then I plan to clean any grit and grime out, the throttle return springs are particularly nasty right now. I will then re-assemble all these goodies with their new gaskets when they arrive. My goal being that when I go down to install all this gear, all I should have to worry about is installing the Cylinder Heads, Exhaust Manifolds and then bolting the rest on. I want to have the job be as painless as possible, and would love to have it all done in 1 day instead of 2.


I will keep you all posted of my progress. Thanks.