High Revs on Cold start 2012 Levin ZRE182R

[Zuzu1M\\\]

I have a 2012 Levin SX Auto ZRE182R

On COLD start up, after being garaged over night, it will rev to 2000 to 2150 RPM on start up before settling on about 1500 RPM.

It will do this 50% of the time on cold start up, otherwise it starts up at 1500 RPM.

I Have taken it to two different Toyota dealerships, and both have told me this is normal.

My argument with them is, that if it was normal, it would consistently cold start at either 2000 RPM or 1500 RPM, and not 50% of the time.

Has anyone else here on this forum experienced this odd cold start behavior.

[jeffy]

ive experienced different cold starts at revs between 2500-3500 ... its normal

[Zuzu1M\\\]

ive experienced different cold starts at revs between 2500-3500 ... its normal

On what model of Toyota have you experienced these cold start high revs?

Cant see how it can be normal, when there is so much inconsistency in the cold start revs.

It cant be good for the engine having a cold start and revving up to 2500 RPM with no oil pressure.

Could there be a fault in the Cold Start solenoids?

[Hiro]

4AGEs are renowned for revving to 2000-2500rpm when cold, to give an example (and they weren't consistent either)

When you think about it, idle-speed control is actually quite tricky. Depending on the setup you've got a non-linear control method (wax pellet valve, bi-metallic strip, throttle butterfly on fly-by-wire etc), in-built delays/feedback, a constantly varying input (coolant temperature) etc etc, plus there are a multitude of additional factors controlling the idle speed (electrical load from the alternator, air-con idle-up, power steering idle-up etc). If the idle-speed can't sit bang-on the same number all day every day when warm (and they don't), why expect them to be any more consistent on cold-idle? The whole point of cold-idle is to bring the engine (and catalytic converter) up to temperature faster, as well as prevent additional loads from stalling the engine (a cold engine is less powerful than a warm one and more prone to stalling due to internal drag). Cars with finely tuned and controllable idle-speeds can run a lower cold-idle speed due to this greater ability to react to extra loads, older engines or ones with merely "satisfactory" idle-speed control will often just dump a heap of extra revs in to make sure it doesn't stall (go back to the old days of manual chokes on carbies, if you didn't pull the choke out on cold starts it would struggle and stall easily on a normal idle speed)

And oil is up to pressure within a second of cranking, the system is designed with anti-drainback valves etc to retain oil in critical locations, it isn't like you are running a bone-dry engine at 2500rpm for minutes on end.

[Zuzu1M\\\]

4AGEs are renowned for revving to 2000-2500rpm when cold, to give an example (and they weren't consistent either)

When you think about it, idle-speed control is actually quite tricky. Depending on the setup you've got a non-linear control method (wax pellet valve, bi-metallic strip, throttle butterfly on fly-by-wire etc), in-built delays/feedback, a constantly varying input (coolant temperature) etc etc, plus there are a multitude of additional factors controlling the idle speed (electrical load from the alternator, air-con idle-up, power steering idle-up etc). If the idle-speed can't sit bang-on the same number all day every day when warm (and they don't), why expect them to be any more consistent on cold-idle? The whole point of cold-idle is to bring the engine up to temperature faster, as well as prevent additional loads from stalling the engine (a cold engine is less powerful than a warm one and more prone to stalling due to internal drag). Cars with finely tuned and controllable idle-speeds can run a lower cold-idle speed due to this greater ability to react to extra loads, older engines or ones with merely "satisfactory" idle-speed control will often just dump a heap of extra revs in to make sure it doesn't stall (go back to the old days of manual chokes on carbies, if you didn't pull the choke out on cold starts it would struggle and stall easily on a normal idle speed)

And oil is up to pressure within a second of cranking, the system is designed with anti-drainback valves etc to retain oil in critical locations, it isn't like you are running a bone-dry engine at 2500rpm for minutes on end.

Thanks for the informed reply.

My concern came to light due to us owning two identical Corollas, and one has this " problem " and the other car just starts up at 1200-1300 RPM on a cold start consistently.

Go figure...Doesnt make sense.

[Hiro]

You can have two identical-spec cars that run differently to each other and neither is broken, simply due to manufacturing tolerances and variations in fluids, engine condition etc.

In saying that, it would be worth monitoring the situation and if it gets worse then investigating it, but if it's not impacting the drivability of the car then it isn't really a problem, just a "quirk"

[Zuzu1M\\\]

You can have two identical-spec cars that run differently to each other and neither is broken, simply due to manufacturing tolerances and variations in fluids, engine condition etc.

In saying that, it would be worth monitoring the situation and if it gets worse then investigating it, but if it's not impacting the drivability of the car then it isn't really a problem, just a "quirk"

Thanks.

I should have been a bit more clearer with the symptoms.

On Cold start up, ( and this is like 50% of the time ) the REVS start at 1500 RPM for about split second, then SPIKE up to 2000 Plus RPM for about 2 seconds before settling back down to 1500 RPM.

Its the actual spike that is my concern..

Current drive ability of the car is not a problem, my main concern is any future out of warranty problems/faults that might occur due to this cold start condition.

[Hiro]

Is your air-con turned on?

[Zuzu1M\\\]

Is your air-con turned on?

No its normally off..

But now that you mention it, I might try a few cold starts with the headlights left On and OFF, as this could also be the culprit ( ECU could be detecting extra load needed on start up and spiking revs ), as my wife always leaves the lights on when turning off the car, seeing that they go off automatically on locking the car.

[trentmeyer23]

Electronic load sense includes A/C, headlights and power steering. There is a good chance that's all it is.

[Zuzu1M\\\]

Electronic load sense includes A/C, headlights and power steering. There is a good chance that's all it is.

Thanks, but no luck.

Tried various scenarios , but still the high spike revving continues..