Let Your Car Idle For 30 Minutes When Cold.....
Discussion
.30? that's quite a while for an every day car
i do let my off road toy warm up for 30 mins before and event- mainly because i am often driving in and out of cold water, so i like to get everything up and warm before spraying water all over the place.
Waiting for fluids to come up to temp before thrashing an engine is of course good practice.
i do let my off road toy warm up for 30 mins before and event- mainly because i am often driving in and out of cold water, so i like to get everything up and warm before spraying water all over the place.
Waiting for fluids to come up to temp before thrashing an engine is of course good practice.
I just start and go. Having said that the first 2 miles of any journey away from my house are side streets so it's all fairly gentle stuff. If the car is frozen it will run for as long as it takes to scrape the windows.
This applies to all my cars even the Ultima but that does have the advantage of being in the garage.
30 minutes. Absolute waste of fuel and damaging to the environment. I don't even thing that long on tickover is good for the engine.
Steve
This applies to all my cars even the Ultima but that does have the advantage of being in the garage.
30 minutes. Absolute waste of fuel and damaging to the environment. I don't even thing that long on tickover is good for the engine.
Steve
chuntington101 said:
they do say your engine warms quicker with moderate use. although it would be nice to hear how race engine are treated????
thanks Chris.
thanks Chris.
I wouldnt go all out and say full F1 style race engines, but on the Chim I warm up the engine on a fast idle, say 1500rpm (length of zip tie under the throttle body stop), until water temperature reaches around 65-70oC and then shut off by killing the HP fuel pump then the ignition (so I dont run the risk of flooding). Then when my session is called keep the engine at normal operating temperature (about 85oC) in the holding area, by which time oil temp it coming up nicely too, one gentle out lap to make sure everything is ok and tyres&brakes are warming up, then go for it.
I'd imagine 30mins at idle will seriously run the risk of wetting the plugs/or wetting the bores on a diesel.
Regards
Iain
The main reason not to do this is that loads on the valve train are highest at tickover, and on some engines there can be other issues like lifters not rotating at low rpm, meanwhile the oil supply is very poor which can lead to inadequate lubrication. Also, the engine will warm up very slowly at idle which means the accelerated wear and corrosion problems associated with cold running will last much longer. Finally, when you do drive off the engine will be warm but the tyres and transmission won't be, so you will need to go through a warm-up cycle anyway. So leaving the engine idling for half an hour is both pointless and harmful.
It's all been covered on various old threads, and I'm sure the OP already knew all this anyway. Why are you asking the question?
It's all been covered on various old threads, and I'm sure the OP already knew all this anyway. Why are you asking the question?
GreenV8S said:
The main reason not to do this is that loads on the valve train are highest at tickover, and on some engines there can be other issues like lifters not rotating at low rpm, meanwhile the oil supply is very poor which can lead to inadequate lubrication. Also, the engine will warm up very slowly at idle which means the accelerated wear and corrosion problems associated with cold running will last much longer. Finally, when you do drive off the engine will be warm but the tyres and transmission won't be, so you will need to go through a warm-up cycle anyway. So leaving the engine idling for half an hour is both pointless and harmful.
It's all been covered on various old threads, and I'm sure the OP already knew all this anyway. Why are you asking the question?
It's all been covered on various old threads, and I'm sure the OP already knew all this anyway. Why are you asking the question?
Spot on,i think i once read on here about a Tvr agent telling one of you guys not to drive off until up to running temp,what a load of crap that recommendation was
GreenV8S said:
The main reason not to do this is that loads on the valve train are highest at tickover, and on some engines there can be other issues like lifters not rotating at low rpm, meanwhile the oil supply is very poor which can lead to inadequate lubrication. Also, the engine will warm up very slowly at idle which means the accelerated wear and corrosion problems associated with cold running will last much longer. Finally, when you do drive off the engine will be warm but the tyres and transmission won't be, so you will need to go through a warm-up cycle anyway. So leaving the engine idling for half an hour is both pointless and harmful.
It's all been covered on various old threads, and I'm sure the OP already knew all this anyway. Why are you asking the question?
It's all been covered on various old threads, and I'm sure the OP already knew all this anyway. Why are you asking the question?
Do you have anything to base this statement on? An SAE report textbook / IMechE paper / whatever?
Or are you (as I suspect) somewhat misinformed?
Just to add my tuppence to this thread, I did my university dissertation with a well known british/russian sports car maker. I was looking at con-rod design.
Many engines (though not their AJP) have a small oil feed hole up the middle of the rod that draws oil from an oil feed in the crank and sprays the back of the piston. At idle speeds this doesnt work.
Many engines (though not their AJP) have a small oil feed hole up the middle of the rod that draws oil from an oil feed in the crank and sprays the back of the piston. At idle speeds this doesnt work.
From the diagrams & data I've seen it seems true that in general valvetrain loading makes a very significant portion of overall engine friction at low engine speeds. However fundamentally it can't be ignored that valvetrain contact loads are going to be a function of engine speed. With increasing engine speed valvetrain contact loads will increase but (with higher gas loads aswell) their relative proportion to overall engine friction appears to diminish as other friction sources become more dominant (i.e. oil & water pump loads, piston side loading, crank bearing loads, etc) Obviously oil film thickness, surface speed and hydrodynamic phenomenon are going to have a significant effects on the coefficient of friction but these factors are way beyond the scope of here and the subject of many PhD theses.
However if an engine has been tested and developed properly then cold weather testing at light speeds and loads at well below freezing is going to part of the development program. The big OEMs don't spend millions on cold climate chambers for nothing!
Cheers
Phil
However if an engine has been tested and developed properly then cold weather testing at light speeds and loads at well below freezing is going to part of the development program. The big OEMs don't spend millions on cold climate chambers for nothing!
Cheers
Phil
Edited by wheeljack on Friday 6th April 18:48
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