Ok, so I just got this from the dealer on the 7th of this month. After test driving and it seemingly had no problems. As soon as I drove it home, I noticed shaking once I hit 55-60mph. Now I'm losing power when I'm step on the gas. It has 135k miles on it, and from what I'm experiencing I'm sure the previous owner hasn't done much in terms of maintenance. I'm more than frustrated that I'm having problems this early. I'm pretty sure it needs a tune up at the least, but what would be causing the losing power(ish) thing. I barely made it off the exit and when I stoped at the light it was running around 500rpm and shaking like crazy. I'm looking for ideas to trouble shoot since I'm at work and hubby can't come to help; where do I start?

 

MAF Cleaning is a good idea. Then spark plugs, air filter. You might be shaken at 50mph from unbalanced tires, maybe alignment issue. I'd call the dealer you bought it from and see if they'll hook you up.

 

does a check engine light come on? sounds like you have a coil pack on its way out.

 

Is this a reputable dealer you bought this from ? Tell him it's running like crap and have him give it a complete tuneup, including fuel and air filter, throttle body cleaning too. It should be throwing DTC codes and a check engine light as well. That will give you some clue as to what's up with the motor. How does the engine oil look ? If it's not clean like brand new have it changed to make sure there's no crap in the old oil.


-Mike

 

Yes, the check engine light is on, and I pulled code P0302 Cylinder 2 Misfire Detected. I bought it from a Nissan Dealer and have called to complain but got nowhere. I'm assuming this was a trade in. My husband changed the oil with synthetic oil and they replaced the battery because it was not reading right. I checked the air filter it was brand new, and I cleaned the mass air flow sensor, I ordered the plugs and coils because I had already assumed they needed to be changed. I have a PCV Value that I need to install and looks like I will also have to change the brakes as well. I am going to go ahead and put in a new fuel filter since the mileage is crappy but I live in LA so... I figure while we are doing that we might as well clean the throttle body, change the drive belt and the IAC valve so I don't have any more problems later on. If you have any good tutorials that you can share that would be great.

From the outside everything looks super clean, but I haven't taken off the "cover plate" to see how things look beneath.

 

Ok, many used car dealers will wash the motor down with degreaser and a pressure cleaner to make it look good to a potential buyer. What usually happens is water getting into the sparkplug well and shorting out the coil to plug connection. The P0302 code is a misfire on cylinder number two, that's the second one from the front of the passenger side. You should pull that coil off and see if the sparkplug-well is full of water or in fact you have a bad coil. You can fix it by blowing the water out of the hole or with just replacing that coil and see how it runs. Then you can change the rest at your convenience if you want. If you find water in that hole you'll probably find it in others and you'll have to blow them out as well. Don't ever wash the top of the motor down with a garden hose and you won't run into this problem yourself in the future. With the IAC, you don't need to actually "replace" the IAC valve if it's not malfunctioning, just clean it out with some carb cleaner or Amsoil PowerFoam spray when you clean the throttle body and you will be fine. Really the same with the PCV valve, just clean it out so it rattles freely. I would still install a new Motorcraft fuel filter if you don't know when it was last changed. A clogged fuel filter will overwork the fuel pump and lead to more problems down the road. That Berryman's foaming degreaser that they sell at Walmart is very good cleaner for in and around the throttle body. I don't recommend spraying the engine down with a garden hose because the water will get into the sparkplug wells and cause mis-fires.


-Mike