New Challenge- Cold Start

[mike508]

I bothers me that whenever you start cold the engine starts at about 1500 RPM at the time when you have the least lubrication . I know this is to reduce pollution and is the case with all cars but can't be good for the engine.
Has anyone looked at an elegant override for this? I expect you can fool the temperature sensor with a switch and resistor but I would like a better automatic solution.javascript:smilie(':awais:')
With the innovation many have shown on this site I hope someone has thought about this problem and has a better solution.

 

[eskimochaos]

There is nothing to worry about, the only time that the engine is not getting any lube is when you are cranking it...which for me is all of 1 seconds. The second it starts, the has begun to get splashed into the cylinder heads.

 

[mike508]

Re: Re: New Challenge- Cold Start

There is nothing to worry about, the only time that the engine is not getting any lube is when you are cranking it...which for me is all of 1 seconds. The second it starts, the has begun to get splashed into the cylinder heads.

You are correct, the lower end rod bearings and cylinders are lubricated some by splash. The cams, lifters, and internal passages of the rod bearings are pressure lubricated and it takes a little time for this to build up pressure and start oil flowing. That is my concern.

 

[Barefoot]

Back in the day, I would crank my car for a few seconds before I kicked the gas pedal a little to get it to start.

My theory was that the oil pressure would get going before the engine fired.

Hard to do in the current days of fuel injection.

I'm not losing any sleep over it...

 

[Methodical]

Back in the day, I would crank my car for a few seconds before I kicked the gas pedal a little to get it to start.

My theory was that the oil pressure would get going before the engine fired.

Hard to do in the current days of fuel injection.

I'm not losing any sleep over it...

hell, now even the cranking part is automatic! flick the key to the start position for a fraction of the second and the engine will crank until it's started.

 

[CJ3Flyr]

Mike, I wouldn't worry about it unless your talking about starting in -30F or something. Back in the day when 10w-40 was more the norm for oil startup dryness was a 'real' issue. With 5w-20 or 5w-30 the cold flow of the oil is very good. You gain an added leg-up by using a synthetic oil (if you really want it). Synthetics tend to do better with cold flow.

If it really makes you crazy :bonk: and you're targeting 450k miles out of your T4R then maybe a pre-oiler is what you want: http://www.pre-luber.com/preluberkits.htm I have NOT used this specific kit but it is representative of what I am talking about.

I know of no easy way to lower the idle other than putting it in gear. I would say a free-spinning 1500rpm would cause less wear due to intial dryness than loading the crankshaft to hold it at 900rpm (or whatever it would reduce to). Parts that are rattling around a little bit without a load or high forces don't wear very much.

:cheers:

 

[mike508]

I can see no one is concerned about this.

The preoiler looks like an overkill unless you live where it is very cold. My last SUV had an oil pressure gauge so you could see that it took 1-4 seconds for the pressure to come up depending on the temperature. I agree that putting it in gear is not a good solution since it makes the problem worse by putting a load on the bearings. I may still look into fooling the temperature sensor so it thinks the engine is warm for a few seconds but it is in series with the oxygen sensors and purge canister so it is not straightforward.

 

[eskimochaos]

I can see no one is concerned about this.

The preoiler looks like an overkill unless you live where it is very cold. My last SUV had an oil pressure gauge so you could see that it took 1-4 seconds for the pressure to come up depending on the temperature. I agree that putting it in gear is not a good solution since it makes the problem worse by putting a load on the bearings. I may still look into fooling the temperature sensor so it thinks the engine is warm for a few seconds but it is in series with the oxygen sensors and purge canister so it is not straightforward.

I honestly dont know why your worried. The 2UZ-FE v8 engine is the exact same engine from the land cruiser which is designed for the world's HARSHEST conditions. Starting engines in the cold is not a new thing, you have NOTHING to worry about.

/thread