Alloytech 175 Rough idle

[craigwf]

Has anyone noticed there 175 shaking the front of the car around a bit while sitting at the traffic lights. I am interested to know as i have only done about 600ks on my lumina and it seems to idle a bit rough. If its not normal i guess i will have to get the dealer to look at it on its first 3000k service.

[Doctor Bob]

Definitely not normal, get it looked at asap, there have been a few with faulty ignition coils
Rob

[steane]

Mine doesnt shake the front of the car around but you'd hardly call it a smooth engine, not by todays standard anyway. There wouldnt be much point trying to stand a 50c piece up on the engine cover... I would have had more chance of doing that in my old VL...19 years ago...

A chap I just sold my Skyline to (now there was a car with a real engine...) is an engineer for Holden at Fisherman's bend. I asked him about the Alloytec and he said their two major issues with it are vibration and lack of torque. They were quite dissapointed with the motor when they first got to give it a try and have had to spend more money than they would have liked trying to dampen the inherent vibration it suffers.

The positive side of things is that it seems to return excellent fuel economy (provided its not being controlled by the old 4 speed auto) and the price of oil is going through the roof, so although I doubt this sows ear can be turned into a silk purse it does have one thing going for it.

[craigwf]

Thanks guys,

I called the dealer about the problem they told me not to worry about it as they would fix it on the first service. I hope it isnt somthing that will happen all the time it is very annoying you would think a brand new car would idle very smooth.

[vzute]

for the fist 2000 kms but havent noticed it lately

[Utester]

I haven't noticed a rough idle, but what I have noticed is if you rev a car whilst stopped at the lights etc, the whole car gives a shake.
When fitting my strut brace I did notice that these engines have really soft engine mounts, you can actually give the engine a good move to one side with your hand.
I assume this was done to cut down on vibrations but maybe it has introduced a different type of vibration/s??

[BobT]

Yeh, my alloytec 190 seems to have a bit of a miss occassionally while idling or even with a few revs up. I'll get it checked at the next service. It feels as though the engine is running very lean. This could be a fuel economy thing and quite normal but it's not a good look.

[craigwf]

I finally had the car in for its first service have done around 3000k/s now and the rough idle hasnt gone away. I told the dealer about this when i took it for the service they told me that it is normal for this model and there isnt anything they can do about it.

[169Maka]

Hi craigwf,

I recently took my vz berlina into Holden in south melbourne. The also said the rough idle is 'normal' and there is nothing technically wrong with my vehicle (i.e. We (holden) are not going to fix it, it's inherent with the vehicle but we are not going to own up).

They mentioned 'bad fuel' being a possible problem to pass the buck. I was advised that bad fuel can cause pre-detonation in one or more cylinders which can cause this shudder at idle. I was advised by the service rep to drive the vehicle on premium unleaded on a long trip as this will apparently clean any carbon build up which causes pre-detonation and thus minimize the rough idle occuring. I'll give it a go but it seems they are passing the buck a bit by blaming bad fuel. I believe the rough idle is inherent with the vz due to a possible design/engineering fault (engine mounts?). Obviously Holden aren't going to own up to it. Do you think they would do a recall on a engine design/engineering fault? Obviously anything to do with repairing any vehicle engine after market means means huge additional expense to the manufacturer.

I think I was also additionally bull s hited which leads me to believe Holden are aware of the rough idle problem but don't want to own up. The rep also mentioned the rough idle is caused by the engine going into 'displacement on demand' mode whereby one or two cylinders 'shut down' to conserve fuel. This is all well and good but in my research so far on the vz berlina model (and specifically the alloytec motor) I have never come across the alloytec 175kw having 'displacement on demand'. If anyone has information to the contrary could you let me know. I could be wrong on this.

[Kung-Foo-Kamel]

Every allotec I have serviced including my own has a idle problem, if you let it idle for 10 seconds or so it will give a strong kick or 2, then go smooth for a bit the it will kick again

One would almost say its a injector or a plug have a crap for a second LOL

I would have to say the whole V6 Commodore range has always had a slight idle issue compared with fords, I was hoping for better from the Alloytec but I was wrong

So if you VZ does this, theres nothing abnormal with it as they all do it, having had the pleaser of checking out a VE yet, they may have fixed it

[old holden v8]

Every allotec I have serviced including my own has a idle problem, if you let it idle for 10 seconds or so it will give a strong kick or 2, then go smooth for a bit the it will kick again

One would almost say its a injector or a plug have a crap for a second LOL

I would have to say the whole V6 Commodore range has always had a slight idle issue compared with fords, I was hoping for better from the Alloytec but I was wrong

So if you VZ does this, theres nothing abnormal with it as they all do it, having had the pleaser of checking out a VE yet, they may have fixed it

KFK;

O2 sensors I have widely read...what do you reckon? And yes mine has a rough idle at times...although I am on the highway/open road a lot so not so noticeable.

Cheers

Laurie

:-)

[Kung-Foo-Kamel]

No I dont think there the problem, as the Idle issue is common through the range
but what does differ from 04/05/06 VZ's are the Cats and O2 sensors, some have 2 some have 4 some have 4 cats, they have tried many configs but the funny idle issue is still there, in fact my car is worse now with extractors as when it has its little shake, it goes right through the car

I was playing around with my scan tool and it can control the electric throttle in 25rpm incremints, as soon as you hit about 750rpm it stops its little shaky miss thing. Pity I cant make it stay at 750rpm

[vz 914]

Hi would the difference in the number of o2 sensors and cats have to do with the new tighter emissions that came in 1/1/2006 ?

[henrytad]

im experiencing all these problems with my vz alloytec 3.6, i have a rough idle for at least 30 seconds when i start the car in the morning after that it runs just fine. i dont know where to start looking or anything? recently had the cat coverters replaced with hi flow sports and extractors installed but it still hasnt fixed the problem. i was considering getting the car dyno tuned at castle hill exhaust and see if itll change the timing on idle.

[Fenners]

problem normally comes from a dirtly throttle body. buy some carby clean from repco or bursons pull of the intake and clean the crap out of it. then reset computer and away you go. will take some cranking and revving just after to burn the excess carby clean in the manifold but yeh. the problem occurs because the throttle is electronicly driven and is very sensative. had this happen to many cars and has fixed all of then so far. hope this helps.

[henrytad]

is it easy to pull apart the intake?? i wouldnt have a clue how to do it?

[FnomnaVZ]

Unscrew the clamp on the big throttle intake tubing. Unscrew the clamp on the tubing just to the left of the air flow sensor.
Disconnect the small PCV tube which goes into the intake tubing (to the right of the throttle).
The whole intake section from the throttle to the sensor can now be removed with some twisting.

Look into the tubing for oil. Mine had a pool. Drain oil and clean tubing. I found 3-in-1 Tool Cleaner good ($5 supermarket) and doesn't leave residue since it's naphtha based, similar to electrical parts cleaner.

Shine a torch into the airflow sensor section. If there's oil into there, then clean it out - don't spray the sensor insides directly. I found it easier to take that section off, including the airbox lid - clean it all. (The pooled oil in mine had actually made the gasket between the MAF and airbox distort(melt?) and sag, causing oil to leak.

Turn the car to the ON position and use a bit of wood to depress the accelerator pedal flat. (Try and turn off all accessories and don't take too long - you could flatten the battery!! I did that when flushing my coolant)
Look into the throttle body on the engine. Should have some black on it, mostly around the base. Use carby cleaner and a toothbrush to clean all you can reach. Don't spray into the holes where the butterfly pivots/goes into the electrics. Prop a rag under the body to collect all the crap that flows out!

Reassemble all. Start and rev soon after cleaning to dry out everything.

[-scyth-]

FnomnaVZ

You should write a how to guide with pictures. (if it isnt done already). Good work.

[Benboy]

This thread was started in 2005 and last responded to in 2007. For someone to suggest that an engine with ONLY 600 kilometres on it should have the throttle body cleaned indicates to me that they have absolutely no idea of what they are talking about. For an older (higher km's) vehicle YES it MAY assist however using higher octane (95 or so) every second or third tankful will also keeps things a lot cleaner.

[henrytad]

im going to clean the motor out this weekend, as for petrol i filled up with shell V-POWER this morning and ill see how i go. my cars on 140,000km and its definetly been driven the hell out of lol. shes always been good too me so now its my turn to look after her

[FnomnaVZ]

Take some pics and put em up here. The job looks a lot easier than it sounds and should only take about 15-30 mins.