Uh oh ... just before Xmas...car won't start...

[jon_s_brady]

I'm hoping I can get some guidance as I troubleshoot what's wrong with my 2005 Ford Explorer XLT 4.0 SOHC Gas car.

I've been working on fixing a "Service Engine Soon" light issue that was being thrown by a P0401 code. Last weekend I removed the throttle body, cleaned it with throttle body cleaner ( and man was it dirty) and did a Sea Foam treatment as well as removing the EGR valve and cleaning it thoroughly with the tb cleaner.

It cleared the code but 2 days later it came back. I checked the PIDs and 2C says it was getting a EGR Command value of 89.8 while PID 2D said the EGR Error value was -100 which I interpreted to mean that the valve was stuck closed. I cleared the codes using my scan tool and drove it again to get a second freeze frame for further analysis. Lo and behold after almost 90 miles that included two stops and about 60 miles of freeway driving at 70 mph the light hadn't returned.

So this morning I headed off to work to see if I would trip the code during driving in heavy traffic. I got about 8 miles from home and noticed the car overheating so I pulled off into a shopping center parking lot to investigate. The engine cooled down quickly and it didn't seem to need water. It being a cold morning I wondered about a stuck thermostat as the heater wasn't blowing warm air.

I listened to the engine and it seemed to be idling roughly but smoothed out with revs. I wondered if the EGR valve was stuck open and so it idled roughly at slow rpm. I decided to gently take it in stages to get home. I started driving back and noticed what sounded like a loud tapping noise as I accelerated. I took it very gently as the noise disappeared under low loads. I got about 3 miles when I started to lose power. Being on a highway I pushed on for about half a mile to get off the highway. The engine stalled as I got on the exit ramp. The temperature wasn't hot but I gave it a while and then tried to start the engine.

While the starter turns over the engine won't catch. I then noticed 2 strange things. Firstly the word "Test" appeared in the message center briefly and then I noticed that it would show "Low Oil Pressure". In looking at the gauges when I try to start the car, the oil gauge moves to the mid-position while the starter is going and then drops to zero once I stop trying to start the engine. The "Low Oil Pressure" message then returns.

I haven't messed with the oil while I've been tackling the EGR issue so it's an amazing coincidence to have an oil pump go out now.

The car has 146,000 miles on it.

Comments are welcomed!

 

[SyberTiger]

Interestingly enough, the EGR systems are used to pre-heat an engine but they are also useful in cooling the engine while it is running. This is neither here nor there but I thought it interesting you mentioned EGR and overheating in the same thread. You may want to consider the DPFE sensor as having gone bad when you get a P0401 code. READ THIS for grins.

 

[jon_s_brady]

But would it put the engine in fail safe.

The weird part is that I now can't start the engine. I had no other codes - P0401 was the only one. So could a faulty DPFE cause a fail safe condition shutting down the engine?

 

[jon_s_brady]

Bad DPFE Sensor Implications

Can a bad DPFE cause the car not to even start? It turns over but the car just won't start.

 

[BigRondo]

The '04 and up doesn't have a DPFE Sensor, it has an electronic EGR Valve.

Instead of replacing the DPFE Sensor, you replace the EGR Valve.

 

[jon_s_brady]

DPFE vs EGR

As I understand it my 05 has the DPFE built into the EGR valve assembly. It's now a "replace everything" proposition since they combined everything into one module. So I guess I misspoke in a way.

Nonetheless...could a faulty EGR assembly cause the engine not to even start?

 

[jon_s_brady]

2 out of 3 ain't bad?

So I bit the bullet and replaced the EGR valve. No luck...

While in there I checked and made sure that at least the throttle butterfly was responsive to the accelerator.

So I figure I've got air...that's one.

I checked I've got spark (there's still a use for an inductive timing light!)...that's two.

So tomorrow I check I've got fuel. I guess I'll see where that gets me...

 

[SyberTiger]

So I bit the bullet and replaced the EGR valve. No luck...

While in there I checked and made sure that at least the throttle butterfly was responsive to the accelerator.

So I figure I've got air...that's one.

I checked I've got spark (there's still a use for an inductive timing light!)...that's two.

So tomorrow I check I've got fuel. I guess I'll see where that gets me...

I assume you disconnected the battery for 15 minutes when you changed the EGR/DPFE valve so that the computer codes would get reset and the computer could recalibrate the system?

Also, did you clean the EGR port hole that is accessible only from inside the TB. That is, clean the port hole through the air intake hose port. You can read about how I solve an idle problem in post #14 in THIS THREAD. I have a 2002 4.6L so I'm not saying that you have this problem but why not take a flashlight and take a looksie for grins.

With the codes reset and the computer recalibrated it would be helpful to repost the EXACT problem you are seeing now. That is, codes, idle RPM, accelerations issues, etc.

 

[jon_s_brady]

EGR Port

Syber, thanks for thinking of that. I checked out your thread and it looks like my 4.0 has a slightly different setup. On my 4.0 the air intake is lateral across the front of the car with the air intake pointing to the fender on the passenger side. The EGR bolts on to the side of the air intake/throttle body between it and the firewall. When I removed the EGR valve assembly I see what looks like a copper pipe that runs from the EGR into the air intake behind the butterfly valve/throttlebody. This pipe is curved through 90 degrees so I don't think I can push a giant Q tip through it like you seemed to have done for yours. I did however use the red plastic pipe attached to the nozzle of the TB cleaner and sprayed that through it. The fluid came through so while I can't see it directly I'm figuring that the exhaust gases can get through.

I've discsonnected the +ve battery terminal overnight to ensure the PCM resets. The thing is however that prior to disconnecting it last night I hooked my OBD II scanner to the car to see if there were any codes present. It said there were none. I then disconnected the battery for about 30-45 minutes while I removed/replaced the EGR valve. I then tried starting the engine but had no change in the situation. The starter cranks the engine over but it doesn't catch/start. That's when I went and checked for a spark. I put the timing light on each of the 6 plug wires to ensure I was getting spark to each cylinder.

With all the volatile TB cleaner in the intake manifold I'm surprised that I didn't get some kind of ignition. I have yet to check fuel pressure but I honestly doubt that's the issue as I thought I could smell fuel after cranking the engine over for a while and the symptoms leading up to the engine not starting didn't point to a fuel issue - the car started up every time no problem. I was just getting the P0401 code.

I thought I read somewhere in the forum that there can be a situation where the PCM is thrown into a condition where you have to get a Ford technician to reset something - I keep thinking something about a failsafe condition. I'm trying to determine if by disconnecting the PCM overnight that it will reset the PCM back to the factory default/operating condition and remove the failsafe condition. Does this sound right?

 

[SyberTiger]

Sorry, I'm out of my element. However, curious to know if "TEST" still shows up on the message console. Also, just for grins did you try to spray some starter fluid into the intake as someone tries to start it? If you have spark and fuel it should fire. The exception of course would be if your timing belt/chain is screwed up such that your four cycles are not operating in the right sequence such that fuel then spark is delivered at the right time. With your timing light I assume you can check to make sure the spark is occurring at the spec-ed BTDC. I guess I would also suggest testing your compression on all cylinders to make sure you are in spec.

 

[SyberTiger]

What was the final solution to this problem? Any update?

 

[jon_s_brady]

The saga continues...my Explorer is now in my garage and I'm in the process of pulling the engine. I had tried everything I could and so I thought I'd try some different tests. I took all the plugs out and went to check the compression...when I cranked the engine over I had water flying out of every pot...

So I'm down to having to detach the aircon and power steering units from the block, detach the exhausts and then the transmission. All this should hopefully happen this weekend. I'll then hoist out the engine and work on it on a stand. The good news is that I have an old 98 Ranger that I'm fixing for my daughter and it's got a 4.0L SOHC engine as well so I'm getting some good practice at this.

One point to note: Fan Removal - I had read sometimes it's a reverse thread. I can state that the 2005 Ford Explorer XLT 4.0L SOHC is definitely a standard thread. I tried mightily to undo it as if it had a reverse thread. Curious, I tried it as a conventional thread and off it came.

Notes for young players: Go to Harbor Freight and buy a chain wrench to hold the water pump pulley. And I went to my local O'Reilly's Auto (Lake Stevens, WA) where I could get a loan of a fan wrench set. They cost $82 to buy but will loan it for free.

I'm also glad I'm indoors as it's below 32 here in Seattle at the moment...

 

[SyberTiger]

Water in the cylinders, huh? What do you think...head gasket or something worse?

 

[jon_s_brady]

Who knows...I'm taking a wait and see attitude on this. If I had to put money down I'd say aluminum heads are more likely to cause trouble than an iron block but Murphy is a cousin of mine...

 

[wangbungal]

any way you could post a how to on unbolting the engine to the transmission the whole shebang please? im in the process of doing the same thing, water in the cylinders, mine is a 2003 ford explorer 4.0 SOHC, I unbolted everything and im stuck in this part, please have some pics thank you!

 

[jon_s_brady]

Things have got in the way and I haven't got around to pulling the engine yet.

So you've started? And you're stuck? Let me know what you've done and perhaps I can offer advice. I've been reading a lot to try and make sure I get the procedure right.

Have you removed the starter motor yet?

If yes, have you undone the 4 torque converter bolts?

Have you undone the transmission to engine bolts yet?

Perhaps we can help each other out here...

 

[wangbungal]

I have not pulled the starter yet, the last thing i did was to remove all connections in the engine, coz i was looking for some info, some say you could unbolt the TC through an inspection panel, and some said from the starter hole, thats why waiting for you to upload pics lol