Shuddering on startup

[da_warped_1]

Its only happened a couple of times but is getting a bit more frequent, when i startup in the morning i get alot of shuddering from the engine. After about 30 seconds it goes back to the normal operating sound and stops shaking. It seems like it could be an engine missfire but not sure or maybe it could also be the computer retuning itself to deliver the correct fuel/air amount, something like that. I'm not sure exactly.

Any help would be appreciated.

[CRUSTIN]

Could it be better described as vibration? Is it very constant or odd? Does it affect performance? Is there an unusually rich exhaust mix when it happens? As much detail as you can give please

[Killr6]

sounds like your fuel pump.

[da_warped_1]

Could it be better described as vibration? Is it very constant or odd? Does it affect performance? Is there an unusually rich exhaust mix when it happens? As much detail as you can give please

I guess its a vibration but quite noticable the whole car shakes as if it a cylinder is not running. Its only happened about 3 or 4 times in the past year but the last 2 have been within a few weeks of eachother, it doesnt happen too often. It doesnt affect performance as after 30 seconds everything is normal. not sure if the exhaust is rich as im in the car, will check if it happens again.

Do you think it will appear with an error code with a scan tool?

[CRUSTIN]

It may, depends if its a fault with a part monitored by a sensor, and that problem has to be outside a parameter to trigger a code.

Its very hard to diagnose an intermittant problem like that unless someone has encountered it before.

Next time it happens put your hand on the exhaust pipe and feel the missfire, if it's only one cylinder completely failing it will be very constant pulses. If its random... you get the idea. And if the exhaust is constant and smooth its not a missfire.

I'm not sure where to go after that because I don't know what sort of vibration it is, and you can't deactivate cylinders to find the culprit because it will be gone by the time you get the bonnet up.

[CAPRILICIOUS WL]

when i startup in the morning i get alot of shuddering from the engine. After about 30 seconds it goes back to the normal operating sound and stops shaking.

Hate to say this but it could be the timing chain start up rattle as per description provided above

How many Ks on the engine? 100+

Also let me know the sound of your engine while idling at maximum operation temperature?? So after a drive while idling Is it grumbly or nice smooth and persistent.

If it's a misfire type of issue, I'd start by replacing the fuel filter as this could be a cause, and fill up the tank with BP ultimate 98 octane and see how u go if it still exists then check spark plugs and replace.

Maybe try get the sound on vid as that will help us try help you.

Dave.

[VZCALAIS190]

The start up rattle definately does not cause any vibration or shuddering on start up. My Calais does it which is pretty normal in the alloytecs.

[CAPRILICIOUS WL]

The start up rattle definately does not cause any vibration or shuddering on start up. My Calais does it which is pretty normal in the alloytecs.

I know it's a common problem but not really a normal one on the alloytecs.

The start up rattle Will have a distinctive shudder from the engine but will not vibrate the car dramatically however a misfire will shake the ground. Lol

And how bout u VZCALAIS190 How's yours sound while idling when warm? And I don't mean vibration I'm taking about sounds when warm on idle.

Dave.

[VZCALAIS190]

The start up rattle definately does not cause any vibration or shuddering on start up. My Calais does it which is pretty normal in the alloytecs.

I know it's a common problem but not really a normal one on the alloytecs.

The start up rattle Will have a distinctive shudder from the engine but will not vibrate the car dramatically however a misfire will shake the ground. Lol

And how bout u VZCALAIS190 How's yours sound while idling when warm? And I don't mean vibration I'm taking about sounds when warm on idle.

Dave.

That's true... mine sounds perfectly normal on idle has slight fluctuation in revs but i think it may be a coil on the way... Only sometimes it rattles on start up when cold can't understand why though? Filled it with a couple extra hundred mls of oil to see if it reduces the rattle, could that be it you reckon?

[CAPRILICIOUS WL]

That's true... mine sounds perfectly normal on idle has slight fluctuation in revs but i think it may be a coil on the way... Only sometimes it rattles on start up when cold can't understand why though? Filled it with a couple extra hundred mls of oil to see if it reduces the rattle, could that be it you reckon?

This will be one of two things either one of the 3 timing chains have stretched a tiny bit and the tensioners are playing up.

Or the oil drain valve is allowing oil to drain back overnight which causes a lack of sufficient lubrication on first start up of the day.

Never over fill ur oil thou, what oil and grade are u using and how many Ks u on.

[da_warped_1]

Hate to say this but it could be the timing chain start up rattle as per description provided above

How many Ks on the engine? 100+

Also let me know the sound of your engine while idling at maximum operation temperature?? So after a drive while idling Is it grumbly or nice smooth and persistent.

If it's a misfire type of issue, I'd start by replacing the fuel filter as this could be a cause, and fill up the tank with BP ultimate 98 octane and see how u go if it still exists then check spark plugs and replace.

Maybe try get the sound on vid as that will help us try help you.

Dave.

Its only got 90,000 Km on the clock. At max temp the idling is smooth and i have not noticed this problem affect any other operation of the car. If it happens again ill try and get a video going. I run on 95 octane all the time, might look at changing the spark plugs.

I recently changed the paper manifold gasket to the metal/rubber or silicone gasket, is it reusable or will have have to buy a new one when taking the manifold off to access spark plugs.

[CRUSTIN]

I very highly doubt a lack of oil would cause this, when cars are started and an oil gallery is blocked, they actually run really well, untill they seize. And it would take a lot less than 30 seconds to fill the galleries.

[Stewlz]

The metal and rubber gaskets are reusable

[VZCALAIS190]

That's true... mine sounds perfectly normal on idle has slight fluctuation in revs but i think it may be a coil on the way... Only sometimes it rattles on start up when cold can't understand why though? Filled it with a couple extra hundred mls of oil to see if it reduces the rattle, could that be it you reckon?

This will be one of two things either one of the 3 timing chains have stretched a tiny bit and the tensioners are playing up.

Or the oil drain valve is allowing oil to drain back overnight which causes a lack of sufficient lubrication on first start up of the day.

Never over fill ur oil thou, what oil and grade are u using and how many Ks u on.

So what you reckon i should do? Is it easy to change the oil drain valve incase its faulty? Don't wanna be causing more damage if its not the timing chains... Just clicked over 130k i'm using all genuine oils and filters so the oil will be a 10w/30w grade. Should i change to 10w/40w?

[CRUSTIN]

10w40 would be better, 10w30 is for fuel economy.

[VZCALAIS190]

Was told by the guy at Holden to not go thicker then 10/30w when i bought the parts for service... apparanty it can cause damage? Would it hurt to keep using the 10/30w?

[CRUSTIN]

Maybe if you live in Tasmania. I would use 10w30 when new, but after 100,000km, 10w40 is more appropriate. You could use 10w40 when new, but it won't need it. That Holden guy is obviously going by spec, it may cause damage going to 20w50, but that's about it.

So you all those cheap skates who put in 20w50 to get rid of a tick, your doing more harm than good.