135 slow to heat up!

[imported_mega]

Originally Posted by jeremyc74

Take the valve cover off an engine while it's running and you'll see exactl how wrong you are. There's TONS of flow, and oil flows around the hottest parts of the engine, while the water is contained within a jacket and isn't exposed to them.

I have done this, on my E30, there is not that much oil flowing

[jeremyc74]

Originally Posted by creepy coupe

I disagree, because of the size of the block and internals, plus the amount of oil, I'd say 10-15 minuets is about right, my Wife’s Golf GTi used to take 10 miles at 18 degrees "C" to reach optimum temp, unlike the coolant, oil isn't held off behind a thermostat.

The thermostat prevents the water from flowing through the radiator. The oil doesn't have one because there's no radiator for it to flow through in most cases. In our case it is thermostatically controlled to prevent it from entering the oil cooler, otherwise in cold weather the oil would never come up to temp. The sensor is mounted upstream of the thermostate, and that's why it takes forever to start reading.

If you think the oil in your engine is staying below the peg on the oil gauge after 10 minutes of city driving, you really don't have a concept of how much heat an engine generates. There's NO WAY 6 quarts of fluid contained INSIDE the block isn't at the same temperature as the block after a couple of minutes.

[imported_mega]

Originally Posted by jeremyc74

The sensor is mounted upstream of the thermostate, and that's why it takes forever to start reading.

no, it's not

who told you this?

[jeremyc74]

Originally Posted by imported_mega

no, it's not

who told you this?

Ok then, where's it mounted?

[imported_mega]

it's on the front drivers side of the engine head

there are no temp sensors anywhere on the oil radiator or cooling lines

[jeremyc74]

Originally Posted by imported_mega

it's on the front drivers side of the engine head

there are no temp sensors anywhere on the oil radiator or cooling lines

Actually we're both wrong. I did some additional digging and it's integrated into the level sensor in the bottom of the sump.

That being the case, it's being "dumbed down" electronically.

Oil condition sensor

The oil condition sensor measures the following variables:

• Engine oil temperature
• Oil level
• Engine oil quality

The oil condition sensor sends the measured values to the DME.


http://spaghetticoder.org/bmw/wds/e87/

[imported_mega]

I was guessing on the head location, it says oil/water temp sensor without specifing which it does, and it's the only oil one I could find, I did read the level sensor does temp too

but that makes sense, the sump will take a while to warm up

[Alpine135]

Could it have something to do with the all aluminum construction as well?? I remember my Alfa Romeo Spiderveloce which also had an all aluminum engine would take a long time to reach operating temperature as opposed to some of my other cars that had an iron block and aluminum head. Could this also have something to do with it?? Especially in cold weather it takes even longer

[nellison33]

From what I have heard about cars in general, Once your oil temp dial is past the cold zone (which means the very left of the dial), it is better to slowly start reving it higher and higher to get the temp up Faster. Before you know its ready to go! If your car is a manual, downshift-braking helps also.

[JHZR2]

Originally Posted by bluemoon

Maybe when heated on a stove or in a laboratory that's true but not in a car. Coolant does not circulate or circulates very little until the block begins warming. Oil is constantly moving the moment you turn the car on. That's why cars with coolant temp gauges will read normal operating temps much quicker than those with oil temp gauges.

Bluemoon is correct. it takes significantly longer for oil to get up to temperature, as compared to the coolant. Often the coolant will nearly be up to temperature within a mile or two (this is typical on many cars, not necessarily the 135i), whereas it will usually take 15-20 miles of use before the oil gets up to temperature, and yes, the oil will loose heat much faster too...

In my experience with a number of engine families the oil temperature typically trails the coolant by about 20C up to around 15 to 30 minutes after startup (engine design related). The prevailing ambient plays a role too as does the metallurgy of the engine, sump and coolant capacities, placement of thermostats and lubrication and cooling system design and their componentry. "Thermal saturation" of the entire engine assembly is indicated by rising oil temperatures. Before this, we are not at steady state. Many of the additives in lube oils require some "thermal activation".

Some engine have the coolant thermostat on the entry side of the block - others are at the exit. This plays a role regarding thermal shock and the speed of the oil temperature rise from a cold start.

At steady state, the temperatures of oil and coolant can be pretty different. I am a mod at an oil site, and you can find an interesting article on that here:

http://www.bobistheoilguy.com/forums...729178&fpart=1

A realworld plot can also be found here:

http://www.bobistheoilguy.com/forums...264382&fpart=2

[M3_Dust]

it's normal

I've also heard that the N54 won't even make full boost until the oil is at 200F

[dmboone25]

I can usually "feel" when the engine is warm enough to start pushing through the revs--no, you obviously don't want to be revving to 7K as soon as you get in it on a cold day, but it doesn't take long.

We had some really cold days here this winter where I was driving the car up to half an hour, and the oil temp gauge never made it past 200 degrees....but I could tell the car was warm enough. Does that make sense?

On a side note, it is nice on the ///M cars--my dad's M Coupe's redline actually changes as the car gets warmer. Pretty neat.

[creepy coupe]

Let's not forget that oil takes longer to heat than water, just try a pan of both on the stove.

Also alloy warm up quicker than iron, it's one of the main reasons car manufacturers started to use it, as they can control emission faster and claim cleaner engines, not to mention the obvious weight saving.