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Rough Idle/ Spark plug change help.

Silenced

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Hey guys, (prewarning I'm not the most engine/car smart around and don't know exactly how everything is ment to work so some of what im saying might be silly. just let me know! :) )

I'm in need of some advice and help.
I have a Holden VE Commodore V 2006 3.6l and about 6 months ago i could notice it had a rough idle, i left it for abit but when i had the cash i took it in to my local mechanic, they told me "they couldnt find the problem" and said they checked my codes and reset them (for $30.. thanks mate!).
i've never been back to that mechanic since, i had a transmission service that flushed new fluid through to get the old stuff out. i then put it in the next week for its 180,000 service and asked him to check out the rough idle for me (at a different mechanic) and at the end he said i would need a injector clean which he quoted like $500+. i noted it down and have been researching stuff via the internet and mostly justcommodores about rough idles and stuff.

now the mechanic told me the coil packs and spark plugs were fine when he checked it and said the engine shakes on idle. it also does a sort os put put sound at the exhaust. and also the car stalled one day at a cold start on a semi cold 10am , in which i think i put from N to R to quickly, and it wouldnt start again.
after that i went and got a battery test to which they told me it was fine.

i am at ends with this damn rough idle, the car runs like ****. i mean it has a noticeable delay when accelerating fast. ive been straped for cash lately and have been looking at doing this stuff myself to make sure it actually gets done because i feel like i cannot trust these damn mechanics at all. ive been researching how to change spark plugs and how to test them and also coil packs with a multimeter. ive read that you have to remove(or atleast unbold and lift it up slightly) the inlet manifold which im guessing is that silver thing on the top of the engine.


anyway to sum it up:


things I've done to attempt to fix the rough idle:

clean MAF sensor
clean throttle body
transmission flush service
car service
had mechanic check coil packs and spark plugs
reset the ECU*
reset the throttle body *
reset the MAF sensor*

*all via guides on justcommodores with the fuses and let the car check the car, then replace fuses and turn on. also via removing the battery negative terminal and putting on the headlights and pumping the brake.

i have been reading about the fuel filter but it is a whole thing that cant be changed seperately? anyway people i need your help! what do you advise?
EDIT:
also i was told i needed a new serpentine Belt, to which i have been looking at how to change it myself and just buy one on ebay.
i was also looking into the engine shake and i notice that the serpentine belt like shakes abit on one of the bottom pulleys and maybe one could be loose and thats why its shaking. they seem pretty solid tho. so yeah just wanted to add that in.

also the engine code they cleared was most likely transmission related; when putting the foot down fully and it changing from 2nd to 3rd gear at 6100 RPM it would shift and go straight into safety mode. i reset my ECU, got the transmission service and it hasnt come back since.


thank you for your time!

- Jayson
 

gunsmoke

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Wow Jayson u got some stuff going on. Not sure how much i can help. But there are many clever guys on here that will also try.
Firstly need to look at what previous services were done and start there. Particularly the plugs.Your engine should be ready for a set of plugs at 180kms. And yes you will need to lift the intake to change the last two plugs, and PERHAPS some gaskets too. Dont worry about checking the plugs, throw away if you decide to change. The coil packs are worth a try, testing may be worth it, otherwise also a change out . Check the belt by looking at the inside/bottom where the lines/grooves are and see if there is any small breaks in it. If so c/out(use dayco brand or ac delco) . The bottom pulley seems a common problem (def with the V8) so that may need a c/out using a powerbond or dayco brand . This will best be done by a mechanic or someone with good experience.
The thing that worries me is that you had transmission codes. Logically if there is nothing wrong with the box then there should be no codes. This part is a little out of my league, but seems there is a problem there. A reset does not cure the real problem. Also a well tuned engine should not run rough or stall, so that needs to be right then look into the box.
Mate sorry, for the long post and prob not much help. Be assured what you posted was not silly at all for a non car person.
 

ChRiDDa

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Throttle body clean will do wonders for a rough idling engine

Nulon carby & throttle body cleaner ($15) and a clean micro fibre cloth

Do the 8mm hose clamp, remove to one side, spray the rag with the cleaner and off you go

Turn to clean section of cloth, spray and repeat

Follow this process until you're happy with the result
 

bfhoon

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I would find a good mechanic or if you want to do all work yourself I would change all of the below for peace of mind and your car will probably love you for it.

Air filter
Fuel Filter
Engine oil
Oil Filter
Spark Plugs ( Kinda a tiny bit advanced you will need to remove the inlet manifold and replace the gaskets which if they are leaking now could be a possible problem for your rough idle so you kill 2 birds with one stone there )
Check all coil pack
Check all sensor plugs

How old are your spark plugs I doubt they would be your problem but depending on how old they are its a possibility. Could also be dirty injectors apart from that most likely a sensor check fault codes as sometimes a fault or faults can exist without a check engine light coming up. With alot of things that could be causing this rough idle it may be best to find a decent mechanic then they can pinpoint he problem for you and save a heap of money on doing all the above.
 

bfhoon

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Also who changed your spark plugs last. Look at the inlet manifold where it connects and you should be able to see either a metal gasket or the edge of a paper orange gasket. With that many klms on the car if you have an orange paper gasket high chance your manifold has mated\unmated with it a few times during the life of the car when getting plugs changed and now it may be leaking which would cause a rough idle. I just changed my paper gaskets to metal ones which allow you to pull the manifold on and off many times before destroying them. My car had 220,000 klms on it and I know the spark plugs hadn't been changed for at least 50,000 and most likely much longer than that and my car still idled perfect although it does purely run lpg which is much cleaner burning than petrol.
 

Alex05

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Hey mate.

Check your ignition coils cause one might have failed.
Start the car and pull the plug from each ignition one by one. The engine should idle bit rough. If you pull one and it doesn't change the idle then that ignition coil could be stuffed.

If you got some cash invest in a code scanner and check what codes are being thrown.
 

delcowizzid

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the worst thing with these is people leave the old plugs in there so long you end up wiping out the coil packs from them working harder to fire a spark accross the gap
 

Silenced

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thank you everyone for all your great replies!
lets get started:

first and foremost i bought the car in July 2013 at 155,000km's and had just had a service before being sold. i have tried looking in the logbook before but it doesn't specifically state when anything was changed, just when it SHOULD be changed. and thats just certain things not everything.

@Gunsmoke

Firstly need to look at what previous services were done and start there. Particularly the plugs.Your engine should be ready for a set of plugs at 180kms. And yes you will need to lift the intake to change the last two plugs, and PERHAPS some gaskets too. Dont worry about checking the plugs, throw away if you decide to change. The coil packs are worth a try, testing may be worth it, otherwise also a change out .

as stated above i do not know what has been done but will check it out again tomorrow. also when the mechanic checked for rough idle with the spark plugs when i picked it up the car was literally shaking the car door when it was open. (which it wasn't as bad when i put it in).

Check the belt by looking at the inside/bottom where the lines/grooves are and see if there is any small breaks in it. If so c/out(use dayco brand or ac delco) . The bottom pulley seems a common problem (def with the V8) so that may need a c/out using a powerbond or dayco brand . This will best be done by a mechanic or someone with good experience.

I'll have a look tomorrow also, and thanks for the brand recommendation! also im guessing i should just ring up my local mechanic and tell them about it wobbling etc?

The thing that worries me is that you had transmission codes. Logically if there is nothing wrong with the box then there should be no codes. This part is a little out of my league, but seems there is a problem there. A reset does not cure the real problem. Also a well tuned engine should not run rough or stall, so that needs to be right then look into the box.
Mate sorry, for the long post and prob not much help. Be assured what you posted was not silly at all for a non car person.
yeah see i was thinking the same thing. what they actually told me was i may need a new ECU/ECM if it came back again. and also it never happened when i first bought the car, was only after a few months and a little before the rough idle.

@ChRiDDa

I did state that i have cleaned the throttle body above, just wondering if your talking about that or something else? (i removed the air flow thing, unbolted the throttlebody and used the cleaner stuff to get rid of all the black stuff etc and let dry)

@bfhoon

Air filter
Fuel Filter
Engine oil
Oil Filter
Spark Plugs ( Kinda a tiny bit advanced you will need to remove the inlet manifold and replace the gaskets which if they are leaking now could be a possible problem for your rough idle so you kill 2 birds with one stone there )
Check all coil pack
Check all sensor plugs

just wondering how do i change the fuel filter for a VE? i have attempted to google and have been told it cant be changed as its one with the fuel pump? would appreciate your help!
also: engine oil and oil filter had been changed in the service just recently. and i have a feeling it may be the spark plugs or coil packs do you have any links to change it DIY?
and lastly how do i check all sensor plugs? where are they etc? thanks in advance.

Also who changed your spark plugs last. Look at the inlet manifold where it connects and you should be able to see either a metal gasket or the edge of a paper orange gasket. With that many klms on the car if you have an orange paper gasket high chance your manifold has mated\unmated with it a few times during the life of the car when getting plugs changed and now it may be leaking which would cause a rough idle. I just changed my paper gaskets to metal ones which allow you to pull the manifold on and off many times before destroying them. My car had 220,000 klms on it and I know the spark plugs hadn't been changed for at least 50,000 and most likely much longer than that and my car still idled perfect although it does purely run lpg which is much cleaner burning than petrol.

great advice! i have no idea who changed or when the spark plugs were changed before i bought it. i will check tomorrow for what type it has. i have been looking on ebay and they have metal gaskets and a set of good spark plugs for $86 all up, thats what i was planning on doing DIY.. do you recommend going to a mechanic or can this be done DIY?


@Alex05
Check your ignition coils cause one might have failed.
Start the car and pull the plug from each ignition one by one. The engine should idle bit rough. If you pull one and it doesn't change the idle then that ignition coil could be stuffed.
If you got some cash invest in a code scanner and check what codes are being thrown.

is that safe to do? seems dangerous to the engine..? also i do have a bluetooth code scanner i bought for like $90 with software and it doesnt display any codes at all. and i have used this in the past on my brothers ve sv6 and cleared a few before.

@delcowizzid

the worst thing with these is people leave the old plugs in there so long you end up wiping out the coil packs from them working harder to fire a spark accross the gap

i feel like when i change these spark plugs the ones that are hard to reach are going to be ####ed and that the mechanic didnt bother checking them.. also maybe they broke the gasket thing?


thank you all for your replies!
 

Skydrol

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Check your vacuum hoses. I know that are not many but there are a few that can give you a hard time.

The reasoning is that Outside Air is ingested by the engine and is not accounted for. The fuel mix will lean and ignites too quick; giving the impression of a missfire. I would say is an easy thing to do and cost nothing.

Do you have any PCM codes?
 

bfhoon

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@bfhoon



just wondering how do i change the fuel filter for a VE? i have attempted to google and have been told it cant be changed as its one with the fuel pump? would appreciate your help!
also: engine oil and oil filter had been changed in the service just recently. and i have a feeling it may be the spark plugs or coil packs do you have any links to change it DIY?
and lastly how do i check all sensor plugs? where are they etc? thanks in advance.



great advice! i have no idea who changed or when the spark plugs were changed before i bought it. i will check tomorrow for what type it has. i have been looking on ebay and they have metal gaskets and a set of good spark plugs for $86 all up, thats what i was planning on doing DIY.. do you recommend going to a mechanic or can this be done DIY?



Im not sure on the fuel filter have not done mine yet as my car runs lpg flat stick so I change my lpg filter which is in the engine bay. I know earlier model commodores had the filters just after the fuel tank and are easy to change you might be right with the ve being at the top of the tank someone here will be able to confirm this.

As for the spark plugs it depends on your ability its def. not as straight forward as some cars. Some cars its very very basic but for the ve it gets a bit harder as to be done properly especially if you dont have top notch tools that fit in tight spaces the manifold needs to be removed or at least propped up at the front. I decided to remove mine completely as you might as well instead of propping it. Once the manifold is removed its a piece of cake like any other car. Once replaced with metal gaskets you can just prop it up next time but propping it up on paper gaskets will crack the gasket and cause leaks. See if you can tell if you have the orange paper gasket this will be a dead giveaway that your plugs prolly havent been changed much and its very possible that if they have the gasket will be leaky due to reuse. Not sure where u are located im in NSW Newcastle if you were local would give you a hand if needed I only did mine a month or so ago so its all very fresh in my mind.
 
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