2006 Nissan Frontier -- Rough Engine

I’ve got a 2006 Nissan Frontier. My engine runs rough whenever I accelerate quickly or drive in hilly areas. The faster I accelerate, the rougher it runs and sometimes the check engine light will start blinking. Once I get up to highway speed, however, everything runs smoothly. It just seems that the engine can’t take a whole lot of stress. Any ideas?

“Any ideas?”

How much time you got? You have a bad misfire under load. If you keep driving it like this you can do some real damage.

The causes of a misfire can be a huge number of things - from old spark plugs, to a failing fuel pump or clogged filter, to a clogging exhaust, to intake leaks to compression issues caused at the top end (valves) or the bottom (pistons/rings/block).

For those on this board you could start with basic info. Mileage? How old are the plugs & wires? Filters? What’s your general approach to maintenance?

Then you need to find out what your error codes are. (That’s what the check engine light means). Many auto parts stores read them for free. The format is “P1234.” Have them read and post the exact codes - not someone’s interpretation of them.

I believe your motor has COP’s (coil on plug) ignition set up. You could be due for new plugs, and one or more coils could be going bad. Lot’s of potential reasons but checking for stored codes could lead you in the right direction.

Truck has 66,000 miles on it. I just had the spark plugs changed last year. The air filter is a bit over a year old (which I’m going to be changing here soon). Not sure about the wires. I bought the truck at 35,000 and have been keeping fairly good upkeep of it. I had some issues with the catalytic converter when I first got it and had to have that changed.

Misfire when the motor is under a load is a strong symptom of a bad coil(s). COP’s all have a rubber boot with a metal spring inside the boot that carries the current from the coil down to the plug. Sometimes the coil is OK, but the rubber boot gets old and the spark arcs to ground rather than the plug.

Great…thanks for the info.

Since the plugs are not that old, when you get the codes read, if you get misfire codes for specific cylinder(s) then I would start by checking out the COP on that/those cylinders. If you end up with a random/multiple misfire code (P0300) I’d be less inclined to look at those.

Of course, there might also be other codes present which could lead in other directions.

Thanks for the advice. You have been a lot of help. I’ll try and find out what those codes are and proceed from there.