I have a 2003 QX4 and it has developed a weird clicking/ticking/rattling sound coming from the engine when accelerating to speeds above about 45mph. The service engine soon light is on and the code is P0300 - Random misfire. When this clicking starts the service engine light starts blinking. If I stay below about 45mph it drives just fine no problems shifting or anything. I have replaced oxygen sensors, all ignition coils and all plugs with no resolve. The next thing I was going to do was replace the EVAP canister purge control solenoid (the one mounted on top of the intake manifold) but this is an expensive part that I would rather not buy to find out it didn't solve the problem. I am at a loss for what else it could be. Any clues would be greatly appreciated.
Thanks
Odd clicking sound when accelerating
Re: Odd clicking sound when accelerating
I think you are describing spark knock or pinging. That occurs under acceleration, and can be caused by using regular instead of premium. Most times you can get away with using regular in these engines, but they do call for premium in the manual.
Rather than try another part, I would clean your MAF with some MAF cleaner, and I would pick up a can of BG 44k and use it in a half tank of gas.
BG 44k cleans out the fuel system. It is pricey at 23 to 28 bucks a can, but it has some fuel conditioners and other stuff in it. What I *think* will happen is that your pinging will go away while you are using the BG 44k, which would confirm the engine ping issue as the source of the noise. You should feel a performance increase and smoother acceleration while using it. Try and get some highway time to help the cleaning.
With a little luck, after everything is cleaned out your pinging will be gone.
Rather than try another part, I would clean your MAF with some MAF cleaner, and I would pick up a can of BG 44k and use it in a half tank of gas.
BG 44k cleans out the fuel system. It is pricey at 23 to 28 bucks a can, but it has some fuel conditioners and other stuff in it. What I *think* will happen is that your pinging will go away while you are using the BG 44k, which would confirm the engine ping issue as the source of the noise. You should feel a performance increase and smoother acceleration while using it. Try and get some highway time to help the cleaning.
With a little luck, after everything is cleaned out your pinging will be gone.
Re: Odd clicking sound when accelerating
Thank you for the response. I appreciate you taking the time to help me out.
**BUSTED** I have been running regular gas instead of premium due to $$$ for the past 4 or 5 years or so but I always use fuel injection cleaner (Lucas) when I change the oil and do two complete fuel system treatments (Lucas) yearly. Bad idea?
I cleaned the MAF (already fairly clean when inspected visually) and the throttle body with the CRC cleaners when I replaced the coils and plugs. I filled the tank with ethanol free premium fuel and added some Redline fuel cleaner (about 2 weeks ago now). I have been trying to burn through that and I am at about a half tank remaining and I can still make it ping when I push it hard trying to get power. Should I go ahead and add some BG 44K at this point or burn all the remaining fuel first?
BTW, Do any of the big name auto stores sell BG 44K?
**BUSTED** I have been running regular gas instead of premium due to $$$ for the past 4 or 5 years or so but I always use fuel injection cleaner (Lucas) when I change the oil and do two complete fuel system treatments (Lucas) yearly. Bad idea?
I cleaned the MAF (already fairly clean when inspected visually) and the throttle body with the CRC cleaners when I replaced the coils and plugs. I filled the tank with ethanol free premium fuel and added some Redline fuel cleaner (about 2 weeks ago now). I have been trying to burn through that and I am at about a half tank remaining and I can still make it ping when I push it hard trying to get power. Should I go ahead and add some BG 44K at this point or burn all the remaining fuel first?
BTW, Do any of the big name auto stores sell BG 44K?
Re: Odd clicking sound when accelerating
Call NAPA or Car-Quest in your area-they should have it. Otherwise, probably Amazon.
I would go ahead and burn the remaining fuel then add the BG. It is supposed to be pretty good at cleaning combustion chamber deposits, so I still think it is worth a try even though you have already used the other stuff. I have had some good luck with it.
Just curious - where are you that you get ethanol free premium? Can't get it here in Denver metro, except at a couple of stations where it is $$$$. Ethanol gas kills my mileage.
You should not have a pinging problem with that gas, so lets hope the pinging is gone when you finish running the BG through it. Also, your mileage with ethanol free gas should be better - if you do the calculations you may find the cost is very close to cheap ethanol gas per mile.
Most people recommend Techron for a fuel system cleaner - I don't think Lucas has a great reputation. The Redline stuff you are using may be pretty good, I just haven't used it.
Anyway, post back so we know if the BG halped.
I would go ahead and burn the remaining fuel then add the BG. It is supposed to be pretty good at cleaning combustion chamber deposits, so I still think it is worth a try even though you have already used the other stuff. I have had some good luck with it.
Just curious - where are you that you get ethanol free premium? Can't get it here in Denver metro, except at a couple of stations where it is $$$$. Ethanol gas kills my mileage.
You should not have a pinging problem with that gas, so lets hope the pinging is gone when you finish running the BG through it. Also, your mileage with ethanol free gas should be better - if you do the calculations you may find the cost is very close to cheap ethanol gas per mile.
Most people recommend Techron for a fuel system cleaner - I don't think Lucas has a great reputation. The Redline stuff you are using may be pretty good, I just haven't used it.
Anyway, post back so we know if the BG halped.