VX V6 Engine Troubles

[Je[Z]zA]

Gday guys,

Car in question is a '01 VX Lumina V6, a mate of mines.

The car is having rough idles and flat spotting from take off intermittently, but once its get to 2,500 - 3,000rpm its fine.

I recently did a major service on it changing the oil, spark plugs, coolant, oil / air / fuel filter and brake fluid. And we also gave the motor a small pressure wash but covered up all the main electrical parts with rags and in case anyone asks we had the car running.

Car has only done 90,000km and for the last 20,000km i must say has been flogged to hell, every part is still factory.

I am an apprentice mechanic but I don't and haven't worked with commodores before so I'm wondering if there is something common i should look out for. I haven't looked at the car since i serviced it a week ago but am checking it out tomorrow to see if I might have made a mistake. Also I'm on holidays right now and have limited tools

If something was still wet and upset from the water surely it would have dried out by now, the car is driven daily.

Sorry for such the big post but any help is appreciated

[Full Spectrum]

Had a similar issue with mine. Flat to the floor was great but that lower rpm was rough and it felt like it would jump into power not ease into smoothly. I changed the coil pack that helped alot try that.

[vxss2002]

Hi try changing the spark plug leads

[Full Spectrum]

LOL he didnt. I thought he done that.

[Je[Z]zA]

Well checked the car out, the work I did it was fine, but like I said this car gets treated bad

Gonna change leads first and see how we go if not then I'm gonna change coil packs. I was more curious if anything electrical commonly plays up.. because on the cars I work on we get it all the time and its a nightmare to diagnose haha.

Cheers,
Jezza

[Dayvo]

Maybe could have damaged the crank angle sensor when you pressure washed it ??

[wrx884]

sounds like spark plug leads check the resistance on each u may have 1 thats dead or on its way.

[f1_power]

Definately sounds like leads

[Theos62]

Hi,
I am having a similar problem with my V6 VX as its running rough at idle.
I changed the plugs, the leads and cleaned the throttle body. Coil spark looks fine and powerful. I am suspecting bad fuel, maybe has fouled the injectors.

Was wondering how you went with yours?
Or if there are any other ideas.
Thanks.

[kaishiz]

i have the same issue with mine too... i had it fixed about 3 months ago by putting new leads and spark plugs in. and it just started happening again about 1 month ago. so i am guessing it is the coil pack that is not right.

Question. does the leads and spark plugs bugger up if the coil pack is stuffed??

and is it easy to install the coil packs or how much would it be to get a mechanic to do it?

[Timzo]

i had the same sort of prob, but mine turned out to be the vaccum hose coming from the throttle body, my engine mounts had sagged, and the pipe was connected to the cai, and that was bolted to the cars body, so every time id rev, the engine would lift up, flexing the pipe, and eventually putting a small slit in the back of it.

[VTS5]

As a app. mech. (if u didnt know the cause) u should of sart with compression test.Could be a cracked gasket,piston,head etc.Then take it from there.plugs,leads,coil packs etc. etc. Dont use the engine for target practicing (hit'n miss) like most of the mech's.

[kaishiz]

so should i take it to holden and diagnose the issue for about 50 bucks??
are there any good holden mechanics in the south eastern suberbs of melbourne??

[Theos62]

I gave up trying to find the cause, as it was getting worse so I took my VX to Holden. They rechecked my initial diagnosis and ruled out the plugs, leads, coil and throttle body, computer readout was fine. Then told me they were confused. So they called a guy in to do an out of car injector clean. #1 was fouled with carbon which was caused by broken valve springs. So they replaced the valve springs and the injector. Ended up costing $450.
Maybe a compression test would have been a good call, then remove the rocker cover and check the valves. Oh well next time.

[buzuki]

wow, broken valve spring, didnt expect that :/. wasnt making noise?

[kaishiz]

soooo should i take my car to holden for a diagnose or should i take to an independent mechanic???