Sun Ra

I find myself waiting until the car hits operating water temp [180F] before drilling it.

It's dawning on me that this is not an oil cooled car [after 10 996's]. When can I stomp on a water cooled car? Deos one maintain 4500 until some Temp less than 180??? I cant find mention in the manual.

Thanks

Steve N.

Watt: As I recall BMW does speak to this in their manual - recommending a rpm limit until certain temp reached. Again, based on memory, this is driven by oil temperature more than water temp (obviously the two will correlate, but there could be many reasons that one would lag the other in the warm-up process.). Water cooled Porsches carry quite a bit of oil compared to many cars, just like BMW's. I have always been pretty conservative - letting the water temp gauge reach "normal" before hammering the car. If we had an oli temperature gauge in our cars it would provide useful input on this point.

Steve

macfly

I have alwyas given my engines around 5 minutes of warm up time before using the top 40% of the rev range. This allows the whole engine, gearbox and drivetrain to come up to temprature. I know this may be conservative, but I grew up around classic and vintage cars, and the whole warm up routine is ingrained in me.

I'm over 10 mins city drive from the nearest freeway, and then another 10 mins or so till I'm out of town, so by the time I get to the great roads my car is hot, so it isn't really an issue. If you live by big open roads, and can tear out of your home and be doing huge speeds immediatly just do the first minute under 4K, then with each minute up it 1K, if you care to keep the car forever. If you'll be trading it in a couple of years then don't worry, be happy!

Sloth

The oil warms slower than the water. I let the water come to temperature and then wait a little longer for the oil to come to temp before I get on it.

skl

This again brings up my point that I wish these cars had an oil temp gauge!!

sjsharks

Not sure about Porsche but my S2000 will not engage the variable cam until a certain temp has been reached.

Jack

Wattster: Just use your on board oil level computer to tell you when the oil is at proper operating temp. Following your early morning start-up, next time you're at a stop light (or standing still) and plan on running up to redline, just hit the oil level measurement program -- if the oil is below min. operating temp (approx. 175-180 degrees) the gauge will post that message (i.e., "oil level can not be measured due to insufficient oil temp" or some such language). On the other hand, if it starts its count down, you're good to go.

And, Sloth is definitely correct, the oil gets to proper operating temp slower than does the water.

Bentley

You gentlemen surprise me! None of you apparently have thought of the fact that you have multi-weight oil in your vehicles. At start-up temperatures, the multi-viscosity oil is designed to flow freely throughout the engine; the additive compounds formulated by the manufacturer are designed to provide additional lubrication where necessary. The old single weight oils featured in the 1930's-1950's needed to heat up for proper viscosity; this is not the case with today's chemical formulations.
All you need to do today is give your engine sufficient time to have its oil be distributed throughout the block and heads for it to be effective.
The same 'M.O.' applies to formulations for the transmission, etc.
Oh! The wonders of modern chemistry.

Steve N.

Oh. I guess the engineers at BMW need to learn this too. Same thing at Honda.

Certainly multi viscosity oil flows much better at start-up temperatures than 30 wt, but the last time I changed multi-vis oil from a warm engine the stuff draining out was one hell of a lot less viscous than the stuff I poured in a few minutes later. So the implication that temperature no longer has an effect on oil viscosity is simply wrong. It has less of an effect than before, with the old single viscosity oils.

Who knows - the manufacturers who have spoken to this issue may also be concerned about internal clearances, etc. which will change as the engine temp increases. I won't pretend to have all the answers, but the comment about multi-vis oil doesn't completely hold.

Bentley

What you appear to not be cognizant of is that the start up thin oil, which is keeping engine surfaces from abrading each other, AT THE MOLECULAR LEVEL, is working just as well, if not better, than the thinner oil, which is in its present state due to thermal shift of being heated due to friction as well as from spark plug ignition exposure. In fact, the heated engine oil is generally less effective in reducing wear than the cooler oil from engine idling for a minute or so; especially if the engine is being runner at high r.p.m.'s. The main reason for this is the inherent imbalance of machined components acting in accentuated fashion from their velocities [piston rings contacting cylinder walls , cams contacting cam bearings, etc.]. The important thing is that all surfaces are coated with oil initially and remain so during operation.
Engine oil DIRECTLY reduces friction and assists in cooling. Water only
DIRECTLY assists in cooling but does act as a lubricant with the water pump.

Johninrsf

The Manual (Page 52) says, "Drive vehicle at moderate speeds and avoid engine speeds above 4200 rpm during the first 5 minutes".
My experience is that the engine will be at operating temperature after 5 minutes of following the factory instruction.
After that, hammer away!!
JP

Steve N.

Bentley: First you contended that other posters were overlooking the fact that muti-viscosity oil basically flowed great at low temp., hence no warm-up is necessary. Then you offer the view that in all reality cold (more viscous) oil works better to protect the engine than fully warmed oil, hence no warm-up is necessary. You are coming and going on this one. If, at the molecular level (wow!) a more robust collection of oil molecules (i.e. thicker film) does a better job of protecting against "the inherent imbalance of machined components acting in accentuated fashion from their velocities" (which, looking at this question in isolation, it probably does) then hey, let's put the straight 50 wt back in. But that would bring about its own set of issues. I will reiterate a notion I tossed out earlier - I think the primary consideration is to get the engine at operating temperature so that clearances - rings to cylinder wall, rod and crankshaft bearings, etc. are where they need to be to allow the oil film to sustain the forces attempting to displace the film and produce metal to metal contact. And by the way, by inherent imbalance I assume you mean, as an example, the downward force on the rod bearing associated with the push of expanding gases from combustion. Oil temperature is probably a better measure of the operating temperature of the critical bearing surfaces than water temperature - the oil is flowing where the action is happening, so to speak, while the coolant primarily cools the cylinder heads/water jacket. So I will stick with my view that oil temperature would probably be a good indicator of whether the engine has been properly warmed up.

I'm done on this one - no mas.

trumperZ06

Watt, many of us Z06'ers wait until the oil temp. gets to 160 F before opening her up! This will take 5 to 10 minutes depending on temp. and traffic. As you may recall ( from Rupardt days), with these V-8's there may be a slight "piston slap" on first starting up. This allows the components to "come up to temp." before full loads are applied!

Roygarth

Great word, but what is 'piston slap'?

Bentley

All engines are made of components which consist of varying metals and alloys of those metals; each with a different coefficient of expansion. If one adds that both the thickness of a part, its shape as well as its location in the engine also effect expansion, then one can at best generalize at what temperature is optimum for all components in engine operation. However, the missing link is the oil dispersal throughout the engine the first minute the engine starts up. Once that has occurred, the different expansion rates are a moot point. The majority of engine wear takes place during the first minute of operation since thorough dispersion of engine oil may have not already occurred.
The water temperature which was initially mentioned in this thread is of minor importance regarding engine friction on startup; the engine oil distribution IS VITALLY IMPORTANT. One's engine oil temperature is much more important. But the fact remains that a good grade multi-viscosity oil will satisfy the engine requirements after a mere minute or two [to make sure it has been dispersed throughout the block and heads]. Waiting for five or more minutes before 'hammering' the engine may be good for the psyche but does little more for the engine after dispersion is already accomplished.