Misfire 3.7, 4.7 Dodge or Jeep – Falling Rocker Arm Problem

10:52 am Chry. 4.7 Problems, Consumer, Jeep
Dennis_and_Truck
Dennis Bandy and his 2007 Dodge Dakota truck
Summary: A severe misfire with a 3.7 or 4.7 Dodge or Jeep vehicle that is accompanied with an engine noise on the top end and backfiring through the intake or exhaust could have a fallen rocker arm. This is becoming a quite common and somewhat puzzling occurrence. Learn what the leading cause of this problem is and if the repair could possibly be covered by the manufacturer’s warranty. Owners of a 3.7 or 4.7, discover what steps can be taken to help prevent this problem from occurring in their vehicles.
A misfire alone doesn’t necessarily mean that a rocker arm has suddenly fell out of place. More common causes of a misfire could be a bad coil, worn plug or plugged injector. However, many 3.7 and 4.7 engines are having problems with the rocker arm falling out of place and this is very disturbing! I personally find this troubling because I own a 2007 Dodge Dakota with a 4.7 V8. When I learned of this increasingly common issue, I set out to find the cause, the fix and steps that I can take to prevent this from happening with my truck. A misfire with a “rocker arm out of place” will be a very severe and notable misfire. There will also be a popping noise that’s most likely a backfire through the intake or exhaust. The rocker arm could be laying on the top of the head – out of commission.
It’s important to know that Chrysler does offer a 7 year/70,000 mile drive-train warranty on some vehicles between 2005 and 2007. Engine or transmission problems may be covered after paying  a $100.00 deductible. Maintenance records are likely to be required because claims for failures resulting from lack of maintenance will surely be denied (i.e. sludge). It’s best to determine if there is any warranty in place prior to starting with “tear down”. Have the VIN number handy and call 800-CHRYSLER (800-247-9753) or 877-IAM-JEEP (877-426-5337). Your local car dealer’s service department will be able to check the warranty status as well.
The first step is to scan for an engine fault code. The CEL (Check Engine Light) will surely be flashing indicating a severe misfire. Flashing CEL’s also mean that if driving continues the catalytic converter can be damaged quickly since there’s so much raw fuel being burned inside it. The fault code will pinpoint the cylinder that has the problem. For example a “P0302” means the number two cylinder has a misfire. There’s no sense in removing both valve covers because the side can be determined by checking the firing order and locating the bank which has the problem. After the valve cover is removed, inspect for sludge, a broken valve spring and quite possibly a “FALLEN ROCKER ARM”.
Dodge_3.7_Firing_Order
Dodge/Jeep 4.7 Firing Order
 

The general consensus among several master techs that I discussed this problem with is “the main cause of  a fallen rocker arm in a 3.7 or 4.7 is from excessive carbon build up.” Carbon build up on the valve stem can cause the valves to stick momentarily. If the valve sticks for a fraction of a second too long, the rocker arm can be allowed enough clearance to fall. Other causes can be faulty valve seats or worn or defective valve springs.

Preventing Rocker Arms from Falling

One indication of carbon build up is a slight tapping noise. Usually the tapping sound can be more pronounced when cold. Detergents used today in fuel may not be enough to reduce carbon build up on 3.7 and 4.7 engines. Using an additive occasionally may be beneficial as a preventative measure. If the carbon is already built up to the point that there’s tapping, running a fuel injection cleaner through the engine may be more affective. Look at the related links below for the Fuel Injection Cleaner Kit made by OTC that every 3.7 and 4.7 owner should have. One way of knowing for sure how much difference an additive makes is to check the valves through the spark plug holes with a borescope or video camera before and after running the additive or cleaner. When it comes to falling rocker arms in these engines, one thing seems to be for sure… “an ounce of prevention can be worth a pound of cure.”

 

Related Mechanics Specialty Tools

Miller Tools Rocker Arm Remover MLR 8516A

Miller Tools MLR8387 Dodge Valve Spring Compressor

OTC 6689 Chrysler / Jeep Master Cam Alignment Tool Set 

68 Responses
  1. angela :

    Date: November 17, 2015 @ 2:05 pm

    I have a 2006 dodge durango 4.7 with 178K miles. It has had a rapping tapping noise at startup that seems to go away after a few minutes since about 120K miles. Last week the CEL came on, went off for a day, came on again, off again, this morning it was on again so I hurried to autozone to get codes. They said P0300 and P0058 B2 S2. I am also definitely due for an oil change. My question is could these codes be related to the tapping noise? And if a seperate issue what might the tapping be? Also, if I’ve gotten sludgey from my slackness changing the oil what can I do to desludge? I appreciate any help!! Thank you

  2. dennisb - Auto Tool Sales :

    Date: November 17, 2015 @ 2:15 pm

    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.

  3. Mark Woodward :

    Date: December 2, 2015 @ 1:10 pm

    I have a 2002 Dodge Ram 4.7L with 106,000 miles. I have reinstalled the hydraulic lifters on 2 different positions. I have used seafoam and other off the shelf cleaners to clean valve cover, cam shafts, lifters and springs but the heads still have grime/dark stained areas that have me concerned. I’m in the process of replacing all 16 hydraulic lifters and have heard that you can spray kerosene or an ATF into the exposed cam area that will better clean the head oil/water ports. Have you heard of doing this? If so, would you recommend this process or something different? I DO NOT want to pull the heads. Any insight would be greatly appreciated. Thank you!

  4. dennisb - Auto Tool Sales :

    Date: December 2, 2015 @ 2:53 pm

    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.

  5. Justin :

    Date: December 30, 2015 @ 2:08 am

    Currently working on a 2011 ram 1500 3.7

    Customer stated there has been a light ticking that over the last 2 years several local shops to Houston TX have told him was lifter tap and could not be repaired, some stating it is normal. Well, the ticking became tapping became popping became a hole in the right side valve cover and a parking lot oil slick.

    After disassemble and inspect, I found a rocker fallen, and a frozen lash adjuster… and the bore of the lash adjuster split in 4 pieces all the way to the bottom.

  6. dennisb - Auto Tool Sales :

    Date: December 30, 2015 @ 10:22 am

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

  7. Tim :

    Date: January 3, 2016 @ 1:21 pm

    Number 3 cylinder spark plug looked crushed what is wrong with my 3.7 motor it’s also locked up

  8. dennisb - Auto Tool Sales :

    Date: January 4, 2016 @ 8:10 am

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

  9. Tedkilroy :

    Date: January 14, 2016 @ 2:27 pm

    2005 Dakota 3.7 has P0303 replaced plugs, coil pack and injector. Found injector pig tail (1) pin cable burnt.

    What burns the pig tail? CEL comes and goes always P0303, thanks.

  10. dennisb - Auto Tool Sales :

    Date: January 14, 2016 @ 2:38 pm

    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.

  11. Tedkilroy :

    Date: January 14, 2016 @ 2:47 pm

    Did a compression test and that cylinder was 150. Only thing that stood out was the burnt pin of the pig tail.

    If I overhaul the engine in the future is the top end of the valve addressed?

  12. dennisb - Auto Tool Sales :

    Date: January 14, 2016 @ 2:56 pm

    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.

  13. paulg :

    Date: January 26, 2016 @ 9:10 am

    2007 Grand Cherokee 4.7L w/ 90k miles. Engine overheated and replaced waterpump. After that repair their was a bad knocking and #8 cylinder fault. Took to shop and they removed cover to see fallen rocker arm on #8 exhaust. Got new lifter and compared to one from vehicle and it looked like it was stuck fully out. Replaced lifter and rocker arm still very loose. Shop says the exhaust valve is stuck open and it is either dropped seat or excessive carbon build up. They said either way it needs a valve job ($2900). Does that sound right?

  14. dennisb - Auto Tool Sales :

    Date: January 26, 2016 @ 10:16 am

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

  15. JasonH :

    Date: February 25, 2016 @ 8:01 pm

    2002 Dodge Ram 1500 4.7. Has thrown 2 rockers. After putting them back on, it threw one of them again. The lifter and rocker were replaced. Since then (3000 miles ago), there have been no problems. I am going to replace the lifters. Do you know which manufacturer makes the best lifters for this motor? Am also considering replacing the rockers. Ford’s 4.6 definitely has the same lifters…would the rockers be the same? If so, would I do well to replace the rockers with a Ford aftermarket design, as there seems to be limited options with Dodge? I’ve also noticed the hole placement on the original rockers (for the 4.7) is different from what is being sold now. Do you know why? Any advice is appreciated. Thanks.

  16. dennisb - Auto Tool Sales :

    Date: February 26, 2016 @ 9:07 am

    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.

  17. Mad at Jeep :

    Date: March 10, 2016 @ 5:04 pm

    2005 Grand Cherokee 3.7, replaced spark plugs and now fuel injectors stopped working on left side? Checked and rechecked all wires and fuses.

  18. dennisb - Auto Tool Sales :

    Date: March 10, 2016 @ 6:28 pm

    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.

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