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Early Driving - Oil Temp vs Engine Revs
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09-27-2012, 07:01 PM | #1 |
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Early Driving - Oil Temp vs Engine Revs
I have never really given this any consideration before, but over last few months have noticed a few people stating about not revving the engine hard until engine oil is at normal temp around 90-100 deg.c
The reason I ask now is do read m3cutters board as well and some chap selling his car stated his M3 had never been above 3000 rpm before oil got to normal running temp. Was rather surprised that a new modern car would need this? So what would people generally advise plz Have a 335i and tbh I do not really rev it past 5000 rpm much at all during any driving conditions Though I guess at times had it at 4000-5000 rpm when the temp was still cold ie within first 60 secs of running engine |
09-27-2012, 07:58 PM | #2 |
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I don't rev it over 3k until the oil is hot too.
just imagine you're cooking some eggs in a pan , grab the oil and its all thick and slow when you pour over the pan....once its heated up it's like water very runny.. i assume the oil heated up will get into every little gaps easily to provide lubing. you know..the more lube the better right =]
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09-28-2012, 03:18 AM | #3 |
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no really to do with the oil
The most wear in an engine happens while the engine is warming up. As different metals have different coefficients of expansion, the engine only reaches its normal operating tolerances (gaps and clearances) once all the individual parts have reached operating temperature.
Oil temperature is the best indication of the overall working temperature of the engine, thus when the oil has reached operating temperature you can be pretty sure that the engine can tolerate high cranking speeds without excess wear to any of its components. Its also about the oil to some degree in that hot oil is less viscous and flows around the engine more readily. By itself, oil moves away from heat (pour oil into a hot pan and watch it dance away from the hot spots), so lubrication is best done under pressure, forcing it into bearing and between metal surfaces. Finally ECUs set fuel supply very rich in cold engines to prevent stalling and hesitation. Revving a cold engine hard is very fuel inefficient and tends to leave deposits in and around combustion chambers (cylinder heads, exhaust valves), which bake hard as temperatures increase and cause the engine to run less efficiently. So all in all, bad practice to rev a cold engine too hard |
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09-28-2012, 04:51 AM | #4 |
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Drives: 335i (sadly gone)
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I would never rev past 2.5-3k or use anything like WOT and drive like a grandma untill the oil temp has moved well clear of the bottom line. in our 335i's it seems to take forever but it just doesn't feel right.
Be nice to the car and hopefully it will reward you for it. |
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09-28-2012, 05:30 AM | #5 |
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Lol turbo engines have only been around for a few decades, revving any engine hard from cold is bad news but it's doubly so on a turbo engine. You also need to let it cool down properly on the way home, ragging the nuts off it and then parking up and switching the engine off is also a no no.
It still amazes me how so many people know so little about how to take care of what is probably the second biggest investment of money in their lives. |
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09-28-2012, 06:49 AM | #6 |
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Thanks for the replies chaps
I guess with having a golf gti turbo car as well for so long, the oil temp in that like gets to 90 deg within 30 secs of driving so you do not have to think about it But the BMW seems to take much longer to get to 90-100 deg for some reason, I just take it abit more easy early doors for now |
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09-28-2012, 07:18 AM | #7 |
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the other problem is that many E90's don't have an oil temperature guage on them at all. Mine certainly doesnt. So i put on the oil level sensor page on my i-drive, and when it registers a level, i can assume the oil is up to temp and being read correctly. Then i give it the beans
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09-28-2012, 07:19 AM | #8 |
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Drives: 335i (sadly gone)
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The golf oil gets to 90 deg in 30 secs? Either that is a very clever engineering trick or there is only a thimbul of oil in it. Are you sure it is not the water temperature you are looking at?
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09-28-2012, 07:27 AM | #10 |
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I'm always concious of this and for me donj't go above 4000rpm until it's at least at 100 degrees even though this takes absolute eons at times. I think the E46 M3 used to have a light warning thing around the revs that changed with oil temp, that would be useful here. Even my old S2000 disengaged VTEC until the car was warm...
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09-28-2012, 07:38 AM | #11 |
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Admittedly the 335i does seem to take ages to get up to temps (can be very frustrating sometimes) but you have to remember it's a pretty big capacity engine with TWO turbo's on the N54 at least so it will take time for the oil to heat up.
I do find once it's up to temp though it takes ages for the oil to cool down again. I've parked the car up for over 30 minutes before and come back to find the oil temp has hardly gone down at all. |
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09-28-2012, 07:56 AM | #12 |
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Im ALWAYS wait until the engine is proper warmed up before flooring it...
Have you not heard of foreplay OP?! You have to make sure the lady is fully lubed up and all warm n wet before you start pounding!...You're not a gentleman!... |
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09-28-2012, 08:08 AM | #13 |
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09-28-2012, 08:08 AM | #14 | |
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Quote:
I followed your advice on another thread and this is what i now do. Normally takes 5-10 mins for mine to give an oil level. |
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09-28-2012, 08:10 AM | #15 |
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