Engine Misfire P0300

[Sam_100]

Hi guys, I posted this on an existing thread so not sure it's got much exposure so trying again for some feedback. The car on two occasions has thrown up a P0300-00 error code. Each time I have cleared and everything seem fine.

First time was driving the car, engine light came on and the service ESP warning. I turned off the engine at the next set of lights, restarted the engine light turned off. I cleared the code with a scanner and haven't had any problems. The only thing I noticed was the down shift on the transmission felt harder. The second time was this morning when I started it using remote start. The engine turned on but was not running smoothly and turned itself off. I started the engine again, connected the scanner and it had the same fault code - P0300-00. It didn't seem to run well at this time until I cleared the code. The car also hesitates on take off sometimes. This has all happened just after I changed the spark plugs.

After clearing the code, the misfire count on the scanner for the cylinders is 0. The only thing the scanner has thrown up in addition to the code is the following. I assume this can be discounted as the source of the misfire.



Also, the evaporative solenoid surge valve is very noisy when I turned it on through scanner. You can hear it on this video near the end -

- It's making a ticking noise.

Edit - Forgot to mention the scanner is picking up a malfunction. see attached picture.



Is the noise it is making normal? Could this be causing the misfires?

Any other areas that I could look? I might need to replace all the spark plugs.

Regards.

 

[MaxCommie689]

How many kms has it run? How old is your car's battery?

 

[Sam_100]

How many kms has it run? How old is your car's battery?

Car battery is 3 month old. 120k km on the clock. It was running fine before the plugs were changed. I am going to check them on the weekend to see which ones have been installed. I think the NGK LTR7IX-11 plugs have been installed of the ILTRE611. Looking at the NGK specs the former are for LPG engines.

 

[dassaur]

Car battery is 3 month old. 120k km on the clock. It was running fine before the plugs were changed. I am going to check them on the weekend to see which ones have been installed. I think the NGK LTR7IX-11 plugs have been installed of the ILTRE611. Looking at the NGK specs the former are for LPG engines.

Purely in terms of the plugs, the difference between the two is the heat range. The LTR7 are one stage hotter. On the v6 I am not sure what difference that will make but could be worth investigating.

 

[lout]

where did you buy the sparkplugs as there are many counterfeit on amazon and ebay
if it started after changing plugs
then i would be changing them out again

 

[Sam_100]

My mechanic ordered the plugs through his parts supplier so shouldn't be counterfeit items. I have ordered the correct ones to fit.

This morning I was going to remove and check the plugs but have got the right socket for the job. Anyway, I started the car to see how its running and noticed that when you rev it from idle it momentarily makes a vacuum cleaner sucking noise and then it goes away. However the engine runs smoothly.

I might have a vacuum leak somewhere. Looks like something has gone loose in the process of changing the plugs or its just coincidental this problem has appeared. I might get a recording of it and post it online.

 

[Skylarking]

My mechanic ordered the wrong plugs through his parts supplier so shouldn't be counterfeit items. I have ordered the correct ones to fit.

Fixed it for you… but must have missed something…

So you are ordering the correct parts and fitting them at your cost? Why isn’t your mechanic fixing his mistake since he was the one that ordered the wrong (not correct) parts and presumably fitted them?

 

[Sam_100]

So you are ordering the correct parts and fitting them at your cost? Why isn’t your mechanic fixing his mistake since he was the one that ordered the wrong (not correct) parts and presumably fitted them?

He's gone overseas for three months on a holiday. I will speak to him when he get back.

 

[Sam_100]

Worked out the air sucking noise. It's coming from the PCV that connects to the manifold. It only does it when you give the accelerator a squirt from idle. You can hear it in this video at the 4 sec mark -

I have not noticed/heard this sound before. Is this normal for a VF LFX (and am chasing shadows) or do I have a leak somewhere?

My OCD is starting to kick in with this problem

 

[Skylarking]

Just curious if the sound still occurs if you press down on the PCV valve or gets worse if you push the PCV valve to the side while giving the throttle a squirt ?

If so, maybe the rubber grommet the PCV fits into has hardened which is hopefully an easy fix.

If not, maybe the PCV valve is a little blocked and it’s just gasses moving through the valve that’s creating the noise and cleaning yje valve may reduce the wheeze…