LS1 Engine Warm-up Time..

[s_ikari2015]

at idle it should be sitting around 2.5-2.8l/h (manual). That's when it has reached "normal" intake temperature and the temp gauge doesn't matter as it pretty much won't go lower than that.

In these colder than usual mornings mine is taking around 5-8 minutes to reach that.

 

[ConstantVelocity]

Mine takes about 10 min to get to normal, maybe 15 on an icey canberra morning. I don't know why Holden set the manuals to idle at 800 rpm, i dropped mine to 600 (with hptuners) and idle fuel consumption is down to 1.6-1.7L/hour fully warmed up, was around 2.4-2.5 stock. Easier to creep in carparks etc too, and sounds and feels better, also reduces rev hang when changing gears. Worth looking into if/when you get a tune, the desired idle airflow does need to be dropped to suit though.

Does sound like OP's thermostat is stuck open.

 

[BlackoutSteve]

I think the slightly high idle speed may be for emissions reasons.
A slower idle rpm generally has more intake reversion/exhaust dilution and unburnt hydrocarbons passing through the exhaust.
Not saying that's the reason, I don't know, but I'd say it's the most likely.

Pre EFI and emissions days, manual transmissions were allowed lower idling speeds than autos with identical engines.
When emissions came in during the later 70's & 80's and carbs were still in use, idle speed adjustments, set by the factory were locked out and non adjustable.

 

[BlackoutSteve]

Yep.. Some cheap-arse silicone-king has been here before me and RTV-ed an O-ring.
If you look closely in the center of the used thermostat, you will note the rubber seal is missing. This allowed water to flow while closed and was why my LS1 would take ages to heat up. I also feel that the temp it was operating at was wrong because as mentioned, it never really heated up beyond 1/4.
Now it quickly warms in just a few Ks and sits on a 1/3 of the gauge. Perfect.
Thank you everyone.

New part number..

 

[Towcar]

mine takes about 5 min, about 6.6km.

I get out of my driveway and do 1.8km of fairly windy at around 80km/h then the rest is on 100km/h with small hills, that is where is gets to operating temperature and sits there

 

[Brett_jjj]

My VS V6 used to take around 5 minutes to get up to operating temp, after fitting pacemaker extractors it now takes about double the time to get up to temp, and it also runs slightly cooler overall now too...

 

[BlackoutSteve]

That's interesting.. No doubt the cast iron manifolds are decent sized-heat sinks and the extractors store less and dissipate heat much better, I would have still expected the engine itself to be a big enough heat sink for no noticeable change..
Where did it drop to? 1/4 on the gauge?

 

[Brett_jjj]

Yeah it was running around 3 marks above cold on the temp gauge and now it runs around the second mark above cold, so it dropped it by nearly one full mark on the temp gauge.