Misfire 3.7, 4.7 Dodge or Jeep – Falling Rocker Arm Problem
April 25, 2010
Chry. 4.7 Problems, Consumer, Jeep
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/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