03 frontieer sc is a dog!!!!!!!!!!

[RB24D]

I have a 03 frontieer sc 2wd crew cab and this thing is SSSSSSSSSSLLLLLLLLLOOOOOOOOOWWWWWWWWWW! It does good when first starting up but after it starts to warm up and when on the highway it is a dog .Are all of them this way ???? It has 110k and I will be getting the timing belt ,water pump, front seals, and all drive belts replaced . Is there anything else my nissan master tec friend should do for me to help this out ? It also gets pretty bad gas mileage and I run 93 octane. Any and all advice is welcome.....Thanks in advance

[Q451990]

Heat makes everything slower, since the air becomes thinner. We have certainly had plenty of heat in Columbia over the last week or so. My Q is noticeably slower during the dog days of summer. I don't drive the G enough to tell the difference, and my truck always seems slow.

What exactly is bad gas mileage? I was able to improve mine by a couple of MPG (from 17 to about 20) by replacing the front O2 sesnor - but I have no idea if that would work with the newer versions. The new ethanolized fuel isn't helping my mileage this year either, since ethanol reduces the BTU of the fuel.

Heath

[nissandoms47]

no check engine lights? Your knock sensor could be bad and would cause that problem.

[vbdenny]

I wouldn't put 93 in it since it burns slower and causes worse gas milage in cars that don't require it. My 01 Frontier with a 2.4L 5-speed has pretty good power but not with the A/C on. I put a K&N air filter on it along with a Flowmaster muffler and it gets around 25 on the highway which is okay since I tend to speed a little.

[nissandoms47]

it requires 93 octane.

[sweet3rdgen]

I wouldn't put 93 in it since it burns slower and causes worse gas milage in cars that don't require it. My 01 Frontier with a 2.4L 5-speed has pretty good power but not with the A/C on. I put a K&N air filter on it along with a Flowmaster muffler and it gets around 25 on the highway which is okay since I tend to speed a little.

FYI. The VG33ER (supercharged) requires 93 octane. Also a higher octane fuel will usually get better gas milage on an engine able to run that higher octane.

I would say have your Nissan tech friend change the belt (was due at 105K) and do a complete tune up (plugs, wires, filters, hoses, belts, etc) and change the knock sensor. The knock sensor has a tendancy to go out around 70K in these trucks.

[RB24D]

Thanks for the replys guys .Sorry for the late response I moved this weekend and have no internet at the new house till thurs.(at work) Just and update the ac compressor clutch went out this weekend that may have been causing paracitic drag on the engine .I will replace the o2 sensor .No check engine lights on. When the operating temp gets up to proper temp and I take off from a light it is very sluggish.When operating teps are still cold it runs like a bat out of hell that is why I was wandering it their is somting you could do to help this situation .I may also concider doing the knock sensor if it may help??

[Desert Rat]

Though it's not a bad idea to replace the 02 sensors, they don't do anything under 3000 rpm.

[jbriggman]

We have had several instances in which customer with the supercharged frontiers have had this same complaint, the first thing we check is for knock sensor codes, if there is a code in the system (won't set a check engine light) that will disable the supercharger. if you look at the valve at the back end of the supercharger (passenger side) you can see if the rod is down- this means that it has cut air flow and bypassed the charger. replace the knock sensor. Also faulty fan clutches can cause this problem as well. hope this helps.

[RB24D]

Thanks will go check it out and see.

[RB24D]

the actuator on the back of the supercharger at the passenger side is in the down position but the engine is currently not running .I cannot re start till wed when my new compressor for the ac will be here. Does the engine need to be up to operating temp and running b4 you check the actuator?

[jbriggman]

No it does not need to be at operating temp, if the supercharger is disabled it is from the time you first start it up cold, when you turn it off hot. I would say that the knock sensor is most likely the problem point, once you replace it, and clear the trouble code you will notice a large increase in power. did you check the fan clutch by chance?

[RB24D]

No Not yet what and or how do you check it ? This is my first frontieer.

[jbriggman]

When you are able to get the motor running again, let it warm up and allow the fan to engage with higher speed. Shut off the car. If the fan clutch feels more loose than it should (no resistance), the clutch needs to be replaced.

[C-Kwik]

I think that is more of an issue with cooling. Meaning if the coolant temps aren't being well regulated because the fan isn't moving enough air. Fans tend to suck up power if the fan clutch fails the other way around and causes it to essentially lock. At high speeds, it tries top move too much air and adds a lot of parasitic drag to the engine. From my experience, this type of failure is usually easily detectable as the motor starts to sound like a small prop plane at higher RPMS.

[RB24D]

Well I should have the ac compressor tomorrow and will check out the fan clutch to see if this is an issue as well .Thanks for the replys. I will keep you all posted.

[RB24D]

No it does not need to be at operating temp, if the supercharger is disabled it is from the time you first start it up cold, when you turn it off hot. I would say that the knock sensor is most likely the problem point, once you replace it, and clear the trouble code you will notice a large increase in power. did you check the fan clutch by chance?

You were right I got the ac hooked back up and got a scan tool from my service dept and it had a 0328 or 0382 can't remember wich but it says high impedance knock sensor trouble code so I will replace that and go fro their THANKS FOR ALL THE HELP!!!!!!!!!!! Checked the fan clutch and all is ok.