Noisy lifters - LS3 - cold start.

[Martyr]

The main thing here is that it happens while ECT is below operating.

Does the LS3 limit power below operating temp?

 

[07GTS]

Does the LS3 limit power below operating temp?

no its no different to at operating temp just the multipliers for cooler ect, iat ect temps come into play so u may be richer and have more timing depending on the situation

 

[monstar]

no its no different to at operating temp just the multipliers for cooler ect, iat ect temps come into play so u may be richer and have more timing depending on the situation

I agree that's true under conditions to make power, in the main, but I think if we define below operating temp by having oil temp less than ECT thermostat setting, yes ECU limits torque via fuel and spark according to RPM and RPM acceleration to protect the engine when cold.
Apart from those conditions purely making power, everything under say 30º coolant temp is affected like cranking and idle fuel air spark, airflow correction and intake charge prediction, injection timing, cold engine noise reduction, DFCO, cat light-off, launch spark, main spark advance and max retard, relationship to intake valve temp (affects fuel dynamics), LT trims, O2 warmup, evap purge, idle and shift in and out of gears, etc.
My point being that the tune can become very different under cold conditions, this variability is a good thing mainly so the bits last or at least don't fail prematurely. Then comes noise and emissions compliance.

 

[426Cuda]

I agree that's true under conditions to make power, in the main, but I think if we define below operating temp by having oil temp less than ECT thermostat setting, yes ECU limits torque via fuel and spark according to RPM and RPM acceleration to protect the engine when cold.
Apart from those conditions purely making power, everything under say 30º coolant temp is affected like cranking and idle fuel air spark, airflow correction and intake charge prediction, injection timing, cold engine noise reduction, DFCO, cat light-off, launch spark, main spark advance and max retard, relationship to intake valve temp (affects fuel dynamics), LT trims, O2 warmup, evap purge, idle and shift in and out of gears, etc.
My point being that the tune can become very different under cold conditions, this variability is a good thing mainly so the bits last or at least don't fail prematurely. Then comes noise and emissions compliance.

Still, the pure dynamics of cold air entering the combustion chamber being better for power production, mean mine is at it's most lively on cold mornings. It's toey as, and I have to be judicious with the throttle, as it'll romp around the tacho with minimal opening.

 

[monstar]

Still, the pure dynamics of cold air entering the combustion chamber being better for power production, mean mine is at it's most lively on cold mornings. It's toey as, and I have to be judicious with the throttle, as it'll romp around the tacho with minimal opening.

Yeah that's what a lot of people think, and if your tune is grossly inefficient normally or setup prone to heat soak then yeah, probably!
In that case (presumably right after warming up) the performance is actually what it should be before ECU implements protection at the other end of safe thermal range. I think it is more a case of your ECU and TCM making judgement calls vs cold protection settings because it is largely going on time-based parameters and low sensor readings for conditions (doesn't really know or care how you drive and where you drive). There are extreme limits during thermal cycling for safety over performance though and I really don't think it prudent to push the boundary, same as above. Car goes better when Intake Valve and Oil temps are at least 90°.
I did some detailed research into chilling down the air intake tract using the air conditioning circuit about four years ago, and realised that unless your engine is severely knock limited during normal / heavy loading then the thermal benefit of frozen dry air is marginal. It is not about an increase in performance at all, rather about safety if your setup can't handle a thrashing under normal conditions by providing a thermal margin before knock.
A very expensive, inefficient and complicated way to artificially introduce octane for safety because your setup needs it. However if your engine's tuned to produce peak performance without knock at reasonable Ambient Air Temperature, there is next to zero gain by introducing colder air.
Take a look under the hood of any cool climate (European) performance car designed to run on premium petrol, the air intake typically provides for heating, not cooling. Except where peak performance from the setup is thermally challenged by knock under typical AAT, like forced injection buzz boxes.
My point is that colder air on a knock free setup is counterproductive. If you notice your car massively better just after warming up then your car needs a tune in order to run like that all the time.
Here's my car after two hours drive in summer Bris - Bangalow, during roadworks at Byron:

The simple equation has zero to do with the impact of air density, because a richer charge is not always going to get you more torque or HP. Whereas with ethanol at 30% in petrol our car makes it knock free even with IAT near 100°C!
So rather than trying to change the world around the car's combustion chamber, I found it easier to introduce mechanical octane in the physical form of better combustion features (like tumble, swirl and squish) through intake, heads and pistons. Oh and variable expansion ratio helps too
Cold air is only good for petrol up to the point it does not need to be colder. Using cold air as octane.. suffice it to say there's better use of resources and more sustainable easy means than trying to maintain a completely artificial environment bubble around a thermally ineffective setup.

 

[Ron Burgundy]

Time to resurrect this.

Went to different dealer about noise on cold start and contrary to first dealer's view (who said this is normal and it's just noisy due to alloy block) they thought my description of the problem is not usual how ls3 should behave.

They requested i leave it overnight for cold start testing.

Will drop it off on 23rd Aug...

Will keep everyone posted...

 

[lmfvf2ssredlineute]

good luck with it Ron, hope it turns out good for you

 

[SSteve]

good luck with it Ron, hope it turns out good for you

+1

 

[KT11H]

We have had series of sub zero temperatures in the mornings when my ute clatters for few minutes at start. But with "warmer" (couple of degrees above zero) mornings this week, no clatters at all.

 

[Ron Burgundy]

I am reasonably confident that in my case no further action will be required. I just wanna hear it from them after they listen to it and have it documented...