Hello all, I have been a long time lurker and the information here has been a huge help. I have just recently started having issues with my Explorer and wanted to see if I could get some assistance.

Vehicle: 2004 Explorer 4.0 V6 (Non Flex Fuel) / Auto Trans / 133,000 Miles

Issue: Engine Miss / Shaking / No Codes

Actions:

New Spark Plugs
New PCV Valve
New Fuel Filter
Compression Check - Around 160psi across all cylinders

History:

About a month ago I had the service engine soon light come on and it was for a misfire on cylinder 1. I changed the spark plugs but that did not seem to resolve the issue. This code would pop up randomly. I have plenty of spark from the Coil and through the Wires.

The issue has become worse and the engine is missing and shaking. If I take the truck out for a drive it has no issues and drives without any issues.

The part that I am stumped on is that there is no CEL light and I am pulling no codes when I scan for them. I have used a Craftsman OBD2 + ABS scanner as well as a Snap On Data Scanner.

If I run a KOEO test I do get code P2271.

I am not sure if it helps but there is a lot of water coming from the exhaust. No smoke. I am not losing any water and the Oil looks normal.

Any thoughts or ideas would be appreciated. I do still have the Snap On Data Scanner if there is any information anyone would like for me to get.

Thanks in Advance,
Mike

 

Not sure what is meant by this statement. Does this mean that the issue occurs just at idle but there are no issues when driving it?

A lot of water will come out of the tailpipe until everything (including the exhaust system) has been warmed up long enough to get rid of condensation. If you get the engine warmed up and then take your Explorer out on the freeway for 20 minutes or so, do you still get a lot of water? How are you checking coolant level - by the overflow tank or taking off the radiator cap and looking in the radiator? Of course, you need to be careful about removing the radiator cap when the engine is hot.

 

The symptoms I described are far worse when the engine is cold or if it is cold outside. On a warm day after a heat cycle or so the engine will idle smoothly as if there is not an issue.

The coolant level does not appear to be changing and the only place to check it on my 04 is at the overflow.

I do know now I am getting an injector pulse to the injector. I removed an O2 sensor on the side with the misfire and there was no change at idle so it does not appear that my cat is clogged.

The spark plugs, wires and coil are new as well.

With that said, what would cause a misfire situation that seems to be affected more by the temp?

One suggestion that was given to me was a lifter but not sure I see a lifter working at one time yet not another.

Thank You

 

I had the car put on a ford scanner and Cyl #1 has low compression but ONLY when it is running. Compression was around 170 psi when just cranking the engine over.

Anyone experience an issue like this or is the motor just junk at this point?

 

How does the business end of the spark plug in cylinder #1 look compared with the other cylinders? If the scan tool is performing the "compression" test it is likely just shutting off fuel and/or spark to the cylinder and checking for a drop in engine speed. The PCM will then calculate an assumed compression level based on the amount of drop in rpm. If that cylinder is running dry or maybe even flooded it could throw off the compression calculation. I would consider moving spark plugs, coils, and fuel injectors around to see if you can find one of those items that causes the misfire to move to a different cylinder.

-Rod

 

Spark Plug from Cyl #1 looks really clean and almost new but I do know for certain that I am getting spark. I also have new wires and a new coil. I have switched the #1 and #2 injector with no change to which cylinder has the misfire.

I am by no means a full time mechanic but I never had an engine show great compression while cranking but have low compression while running.

From what I know, the Service Engine Soon light was on during this test and since it is due to a misfire the PCM will try to regulate fuel to that cylinder to prevent damage from an overly rich condition.

 

Earlier you mentioned that there is no stored diagnostic code, only a pending P2271. Has the CEL only been on when doing the automated compression test? If so, and there's still no stored or active code, I wouldn't expect the PCM to be actively trying to regulate fuel to the cylinder with low compression. If the spark plug were not firing during normal running, I'd expect the plug to show signs of unburned fuel.

-Rod

 

Well, after a few weeks of driving eventually the PCM will throw a P0301 and a P0316 code. Then the CEL light will stay on and from time to time it will flash. When the technician was running the compression check with his scanning tool it showed to be running lean at that time.

The plug has no signs of unburned fuel. It is clean and has a good spark.