Random Missfire -Help

[sniper_HASH]

Hi guys i have a 3.6L 190Kw alloytech in my wm statesman dual fuel.
just hit the 200,000km mark, and the engine light has come up.
had a diagnostic scan done


would replacing the coilpacks fix the random misfire problem?
i wanted to be sure before ordering a set of ngk U5130 coilpacks this week.

also what do i need to do to fix the P0430 fault code?

 

[kwaka738]

From my experience with the P0430 I would get it cleared and wait and see what happens.

Read this:
https://forums.justcommodores.com.au/threads/p0430-check-engine.241301

Regarding the misfire how long is it since the plugs were replaced? If it's quite a while why not replace them (as they are a consumable item) and see if your misfire(s) goes away. If not it might be time for the coil packs?

 

[sniper_HASH]

From my experience with the P0430 I would get it cleared and wait and see what happens.

Read this:
https://forums.justcommodores.com.au/threads/p0430-check-engine.241301

Regarding the misfire how long is it since the plugs were replaced? If it's quite a while why not replace them (as they are a consumable item) and see if your misfire(s) goes away. If not it might be time for the coil packs?

thanks kwaka738,
cheers
seems like do the spark plugs before going to coil packs
and replacing the cat converters may clear that p0430 code.

 

[kwaka738]

Well I would clear the P0430 cleared and wait and see what happens.

From my experience my Alloytec put up the P0420 code (bank 1 or driver's side catalytic converter low efficiency) and because it was bought from a dealer they replaced the driver's side catalytic converter at my expense in November 2012. It cost $580 including their expert fault finding labour!! (back in 2012).

Since then I have had the check engine light come on and P0420 has come up in May 013 (just had it cleared), October 2013 (just had it cleared), July 2014 (was away so didn't have a chance to get it looked at but it went out 3 days later), October 2014 (light went out 10 days later by itself), July 2015 (was away so didn't have a chance to get it looked at but it went away days later).

So.............. I think I have had numerous issues with P0420 (which is almost an identical problem with your P0430 but yours is the passenger side catalytic converter) and I'm not even sure if it ever was the catalytic converter in the first place. If it was why have I had the same problem so many times? I think I may have (possibly?) an oxygen sensor(s) problem which makes the car think there is a catalytic converter problem.

I've consequently bought myself a cheapish scan tool so I can see what the problem is when the check engine light comes on next time. So I would reset the code for now and see what happens. If you have original catalytic converters in your car they are probably at the end of or approaching the end of their life cycle (of the catalytic converters).

But for now I would wait and see. If you don't have a scan tool buy yourself a cheapy. Mine cost $40 which is less than the money they charge just to read codes.

 

[sniper_HASH]

i have had the engine light come on before, its been happening for the last 4 months, i have just been neglecting it. ive had it cleared twice as well, the light comes back after 5 days.
i am thinking about selling the car soon, so i want to diagnose these problems now.
alot of people say the light and code comes back after replacing just the oxygen sensor, so i might change the passenger side cat as well as sensor if i can grab a hold of a second hand one thats in good condition from wrecker. not sure how much they would be brand new.

 

[S.D.M.F]

alloytec P0420 Check Engine light on -

Possible air leak in cold intake air tube between fresh air filter and Throttle body,

1, Check the cold air intake flexible tubes entire condition check for any damage or leaks,
2, Make sure the flexible tube connection properly seated and both ends clips are fully tightened.
3, ensure air intake plastic pipe intact with Cold air tube ( use insulation tape to fix if needed)

Drive about 100 KMs after few stops and restarts, see the results. Good Luck

And you've mastered the 'Cut-n-paste' feature. Nice.

 

[Rustyruss66]

I feel the engine has an issue with clogging of the oil pickup in the sump, the first indication of this is a misfire on cylinders from the OBD diagnosis, cam position sensors get fouled up and can't read correctly due to sludge in the top end, crank position sensor should not have any issue. You need to take the sump off along with rocker covers and clear the oil pickup of sludge, flush and clear all galleys as best possible, flush it through before placing sump back on with a long thin brush and diesel right through all the galleys. Once put all back together, fill to correct level with straight Diesel, run motor at idle for 10-15 mins, if oil warning returns, shut down and repeat the cleaning process, it a bit of a task but will reward you in the end. Once you get the thing clear,, ONLY use synthetic oil,, change every 5000-7000kms. I feel that this will save you from costly coil pac replacement as it won't fix the problem.