Sludge can definitely cause noise since the oil cannot lubricate everything as quickly as it should be able to. Oil not getting to lifters or lifters leaking down may also cause misfires in some cases. De-sludging can cause the pick-up screen to get clogged up. So if you really want to try to de-sludge be prepared to remove the oil pan and replace the pick-up screen. There’s really no substitute for regular maintenance and any wear that has already occurred cannot be undone. Good Luck.

Cleaning an engine that is gunked up can cause the pick-up screen to get clogged. Which would require the oil pan to be removed to access and remove the pick-up screen. I’d avoid trying to clean it unless you’re prepared to remove the oil pan. Good Luck.

Hammer time huh? Not sure why those shops would think nothing could be done.

Something loose in cylinder. Most likely a piece of valve. Inspection will reveal. Good Luck.

Haven’t heard of that particular problem with this application. But usually, burnt electrical terminals in a harness (AKA pigtail) would be loose connections. These circuits would most likely blow a fuse if there was some sort of short. But loose connections generate excessive heat that would show burn marks and eventually a loss of connection (open circuit) causing an injector circuit fault, not a P0303 misfire code. The typical cause of “misfire codes” like P0303, is a spark plug, a coil or an injector not spraying properly. Since you’ve already replaced those, I’d suspect a valve or ring issue. May do a compression test and go from there. Good Luck.

I’d check compression on all cylinders. Too much of a variance, generally more than 10% is not good. Also inspect the plug itself in case oil is getting to it and fouling – just a thought. If rebuilding, I’d replace all lifters and keep the oil changed often and full in between oil changes. Should be good. Good Luck.

Certainly plausible. However, I’d call around and compare cost estimates in your area to see if prices are in line. Good Luck.

I would stick with the OEM parts. Updated versions would be supplied if available from OEM. Any incorrect parts from Ford could possible cause problems/damage. Keep a close watch on oil level and condition. Good Luck.

If they were working before you changed plugs, then more than likely you have unplugged or damaged the FI harness. Sometimes the wires can break inside and the wire insulation can be intact. I would retrace work to inspect for damaged wires or unplugged harness. If that checks out. I’d pull codes and check for TSB’s. I’d get a wiring diagram and see what all injectors on left side have in common. Good Luck.

Hello Donald, sorry not enough information to diagnose. Maybe simple but could mean engine work. I’d take it to a local technician that has the benefit of checking the engine in person. Good Luck.

I’d examine the spring closely, it could be broken or weak. Good Luck.

Allen, good luck. BTW for others reading. We finally have the less expensive alternative to the Miller 8387 and 8516A all in one tool. See the following link.
http://www.denlorstools.com/home/dt1/page_92515/win_valve_spring-rocker_arm_tool_similar_to_10102_.html

I’d start with basics. Spark plugs and coil for the cylinder that misfires. If you want to verify it’s a coil before replacing, you can swap with one beside it and see if the code moves. If there’s tapping, lifters could be getting worn and leaking down too much. We have a lot of customers that change their own lifters with the 3747-13 which is similar to the 8516A Miller.

I personally think both the Chrysler/Jeep/Dodge 3.7 and 4.7 are good engines. The 3.7 is just like the 8 cylinder but two less cylinders (same design). Since it’s based on the 8’s design so much; there’s one problem that it has that the 8 does not. The 3.7 6cyl shakes. Something about the two less cylinders causes it to vibrate until RPM’s are raised. It almost feels like a misfire even-though nothing has to be wrong with it to feel a vibration. I only had the one 4.7 engine. It was in a 2007 Dodge Dakota and I had no problems with it, although I did trade before it had too many miles (way under 100,000 mi.). If I was going to buy one with a lot of miles, especially over a 100k, I would want to make sure the engine is not gunky inside from too few of oil changes. I’d listen to the engine from a “cold” start. Noises like lifters can be hidden sometimes if the seller warms the engine up before a potential buyer comes to test drive. I’d also notice if either one of the valve covers have been off recently. A recently removed valve cover on a 3.7 or 4.7 could mean that there’s a “rocker arm popping off” problem. They could just put it back in place without doing lifters or anything and sell the vehicle to an unsuspecting person. I’d also inspect coolant to see if that was changed often enough. I’d run the engine 20-25 minutes while looking the truck over. If there’s a leaky or outright “blown” head gasket you may see evidence coming from the tailpipe or excessive bubbles going into the coolant reservoir. I’d also find out as much as I could about maintenance and the vehicle’s history etc. It depends on how long they had it and how honest they are about revealing problems. I’ve had many buyers of used vehicles ask me after the title and money has exchanged hands “Now that it’s mine and the deal is done… do you know of anything that it needs?” Hopefully you are a good judge of character and are somewhat knowledgeable about inspecting and finding problems before you get to that point. Good Luck.

Bryan, I’d pull the valve cover and see if the rocker has fallen or not. We sell the 3747-123 that would help you put it back if it has fallen. The tool 3747-123 also would work for replacing the valve spring if needed. Make sure to follow service manual procedures though if doing the spring because there’s a risk of dropping the valve if you don’t do it correctly. We have many many customers that do these repairs. Just a little common sense and experience needed and ability to follow instructions. Good Luck.

If it’s coming form the top end, possibly worn valves.

Sorry Charlie, not sure. Could have been a design change that may have corrected this issue. But was unable to verify. Perhaps your local dealer’s service department could advise?

Of course, this does not prevent the problem of dropped valve seats. If you find a rocker off, check the installed height on that valve. If it is low, the seat has dropped. Engine repairs are necessary. Jasper has fixed this issue on their engines by installing seat with several times more interference in the fit.

Rocker arm came through valve cover last night. Truck runs a little rough with a misfire. What can I do to get a new valve cover? Will the rocker arm be OK?

Good comments. I just bought a 2001 Durango with 159,000 miles with this problem. I had prior knowledge of this problem, so I’m hoping for an easy fix. #5 cylinder has zero compression so I’m figuring a valve is either stuck open or a broken valve spring. I’m taking the valve cover off it when I get home from work today to see what happened.

What did you find out. I have the same problem and both lifters are stuck open on one cylinder which has zero compression. Any assist would be greatly appreciated!