engine light 100% of the time?

[Crocodile]

hi guys just wondering if a engine light will alllllways come on if the timing is out on the engine? just bought a VE 2011 thunder and wanna understand if this rough idle is due to timing chain being out. mechanic reckons there will always 100% of the time be a engine light come on if anything is out of time?
is this correct plz help

 

[Fu Manchu]

The engine light is on because somewhere there is a sensor, or sensors, reading data that is outside it’s ideal parameters.

Without plugging in a decent diagnostic tool, it could be anything of 300 things.

Rough idle has a lot of causes and rarely would the timing chains be the cause.

 

[Crocodile]

The engine light is on because somewhere there is a sensor, or sensors, reading data that is outside it’s ideal parameters.

Without plugging in a decent diagnostic tool, it could be anything of 300 things.

Rough idle has a lot of causes and rarely would the timing chains be the cause.

i have already had it scanned it said o2 bank 1 and 2 ... but im asking if the timing chain can **** itself and show no code at all? am i making sense? can the whole timing chain/pulleys be broke and ecu cant pick up sometimes?

 

[Fu Manchu]

It seems the one thing people know most about VZs and VEs is that the V6’s had timing chain issues.

The issue was not the design. The issue is the motors have no tolerance to poor servicing and even factory intervals were too long, but good enough for warranty periods.

Any factory issues from the early run of the cars has been sorted some 15years ago.

So.

The O2 sensor codes. Were they pre cat or post cat sensors?

Are the O2 sensors Bosch or some other brand?

Rough idle is most commonly due to vacuum leaks and these can have more leaks than a colander.

To solve a vacuum leak, a smoke test is done on the intake system. Where ever there is a leak, smoke comes out and the leaks are found quickly.
Smoke test can be done on the exhaust to find leaks from that end.

• Brake booster
• PCV hoses where they connect to the intake plenum.
• PCV hoses where they connect to the throttle body
• PCV where it connects to the air intake pipe.
• Leaking or damaged MAF gasket
• Damaged or leaking throttle body gasket
• Damaged or leaking intake plenum gasket
• Cracked headers
• Leaking manifold gasket
• Cracked exhaust pipe in front of pre cat sensors.

Any ingress of unmetered air after the MAF sensor will throw out expected dat at the O2 sensors.

Which sensors involved matters. Pre or post.

The brand of sensors matters. Bosch will give you zero problems unless there is actually a problem and the sensor is being the goodest boy. If cheap sensors are being used, there will be months of hurt chasing non existent issues.

The purge valve could be faulty. Simple to remove and test by blowing through.

PCV blocked on the valve/rocker cover. There’s a fix for that in the how to section. Costs nothing to do.

Clean blow out the PCV hoses. Replace the hoses. Or replace the ends with new hose if you’re on a budget.

Also, clean the MAF with MAF sensor cleaner.

 

[Crocodile]

iv

It seems the one thing people know most about VZs and VEs is that the V6’s had timing chain issues.

The issue was not the design. The issue is the motors have no tolerance to poor servicing and even factory intervals were too long, but good enough for warranty periods.

Any factory issues from the early run of the cars has been sorted some 15years ago.

So.

The O2 sensor codes. Were they pre cat or post cat sensors?

Are the O2 sensors Bosch or some other brand?

Rough idle is most commonly due to vacuum leaks and these can have more leaks than a colander.

To solve a vacuum leak, a smoke test is done on the intake system. Where ever there is a leak, smoke comes out and the leaks are found quickly.
Smoke test can be done on the exhaust to find leaks from that end.

• Brake booster
• PCV hoses where they connect to the intake plenum.
• PCV hoses where they connect to the throttle body
• PCV where it connects to the air intake pipe.
• Leaking or damaged MAF gasket
• Damaged or leaking throttle body gasket
• Damaged or leaking intake plenum gasket
• Cracked headers
• Leaking manifold gasket
• Cracked exhaust pipe in front of pre cat sensors.

Any ingress of unmetered air after the MAF sensor will throw out expected dat at the O2 sensors.

Which sensors involved matters. Pre or post.

The brand of sensors matters. Bosch will give you zero problems unless there is actually a problem and the sensor is being the goodest boy. If cheap sensors are being used, there will be months of hurt chasing non existent issues.

The purge valve could be faulty. Simple to remove and test by blowing through.

PCV blocked on the valve/rocker cover. There’s a fix for that in the how to section. Costs nothing to do.

Clean blow out the PCV hoses. Replace the hoses. Or replace the ends with new hose if you’re on a budget.

ive legit just bought the car brother... if i was to take it to my mechanic what would be the first thing of action... i.e what to ask them to do.. need a priority check list haha. any good commodores mechanics in gc that a reasonably priced?

 

[gossie]

First thing is to check the service books that came with the car and if it’s been over nine months since a full service; have it done at your nearest to you mechanic.
At same time discuss with this mechanic any problems you feel the vehicle has.
The longer things are left before repair the more expensive it gets sorry to say.
Good luck.

 

[Skylarking]

@Crocodile, if you bought the car from a used car dealer, the first thing to do is look at the defect list (if there is one it must have been displayed on the vehicle prior to purchase) provided on the contact of sale. If it doesn’t show that there is any issue with o2 sensors and/or check engine light, then go back to the dealer and tell them the car is defective and you’d like the issues corrected as you have a 3 month 5000km statutory used car warranty on top of your Australian consumer law statutory warranty

If you bought the car privately your S.O.L. so reach into your pocket and grab a wad of cash as you’ll need at least some of it to correctly diagnose the issue(s) you're having.

 

[gossie]

When the reasonable priced got mentioned I decided not to recommend mechanics on Gold Coast where I live.
$150 an hour these days because overheads are high and mechanics usually have family that need looking after.

 

[Fu Manchu]

The mechanic would scan it. Check fuel trims and a few other sensors for their live data.

Smoke test the intake to find various leaks. Smoke test the exhaust.

Look at a fair bit of labour to find leaks, replace various hoses.

Lazy mechanics load the parts canon. Fire for effect. Cunning ones will do a major repair to resolve minor issues.

Hopefully someone here can recommend a trust worthy mechanic or workshop.

I have a great deal of faith in the TAT network. They are evidence orientated diagnostic experts that share information between each other. I’d call TAT and find a member near you. Their videos and work is right up there with the best. It’s an area of the trade that very few have skills in, yet it’s the very way these issues are sorted.
https://www.tat.net.au/contact-us.html

 

[Commo64]

It seems the one thing people know most about VZs and VEs is that the V6’s had timing chain issues.

The issue was not the design. The issue is the motors have no tolerance to poor servicing and even factory intervals were too long, but good enough for warranty periods.

Any factory issues from the early run of the cars has been sorted some 15years ago.

Don't know if I can agree with this... My chains needed to be done and it has a full service history, always serviced on time...