# Coolant Temp vs. Oil Temp



## chukiechz (May 15, 2002)

*Re: Yikes!!!*



Stuka said:


> *
> 
> 240 to 260!!!!:yikes: That's track temp for the E46 M3 after sustained 8000 or near 8000 driving. Are you sure there is no something wrong with either the gauge or the engine?
> *


I know, pretty high huh? Its not the engine, because I was getting similar temps on the 2.5. It could possibly be the gauge or the sender. Its an autometer gauge, so I dont think its the gauge.

so its the sender,

or its the heat from the blower increasing my oil temps. Im not too worried about it because I hear that synthetic oils dont break down until very high temps. But its still irritating to be stuck in traffic on a hot day and watch that sucker climb.

When I cruise on the freeway on a cooler day/night, it hanbgs out about 210. Once I hit stop lights, it raises


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## JonM (Jan 28, 2002)

*Re: Re: Yikes!!!*



chukiechz said:


> *
> so its the sender,
> *


Unlikely. Oil pressure senders go bad. Oil temp senders do not. Best guess, if there is an error at all, would be the ground point the gauge uses.

The other option is the gauge is correct and you need an oil cooler or an LTW oil pan.


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## JonM (Jan 28, 2002)

*Re: Re: Yikes!!!*



chukiechz said:


> *Im not too worried about it because I hear that synthetic oils dont break down until very high temps. *


Mobil1 is good till 430 deg F. But the detergents break down a lot sooner than that.


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## chukiechz (May 15, 2002)

*Re: Re: Re: Yikes!!!*



JonM said:


> *
> 
> Unlikely. Oil pressure senders go bad. Oil temp senders do not. Best guess, if there is an error at all, would be the ground point the gauge uses.
> *


you think the ground makes a difference? I might look into that. Might be one of my projects this weekend.

oil cooler is great, but that one piece is so expensive. I can get one for cost from RMS, but $400 is still chunk o change!!!

So the detergents break down at lower temps, does that mean I should be changing my oil more often since Im running higher temps? (assuming it is actually that hot). I change mine about every 4-5K


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## Emission (Dec 19, 2001)

In my air-cooled 911, the oil in the sump heats up in about 10 mintures of driving. After that, the thermostat opens and the oil cools as it flows up to the front oil cooler and the cold oil (in the return line) is introduced. A few minutes later, the whole system is the same temp. Overall 10 - 15 minutes.

I won't go over 3000 rpm (or spin the turbo) until my oil is warm.


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## Pinecone (Apr 3, 2002)

*Re: Re: Maybe the E46 is different*



JST said:


> *Can you retrofit an engine block heater? Not sure how tricky this would be, but it might be nice to put the block heater on a timer; when you wake up, your Mr. Coffee brews your joe and your block heater warms your oil for you. Then, when your water temp is up, it's off to the races. *


Even better, use an oil heater.

Quick and dirty way, use on that sticks down the dipstick hole. Plugs in a keeps the oil warm.

Better way, there are silicone heater panels that you bond to the oil pan. These are used on aircraft engines to get them warm before starting. Nobody with any sense starts an aircraft engine below about 40 degrees without using some form of preheat.

The pad type could also be attached to the tranny and diff to keep them warm. But these are not as sesntive to temp as the engine is. A couple of miles and they are fine.

But if you want to do the block heat also, the heaters just replace a freeze plug. Those cup things on the side of the block. You pop one out, and insert the block heater and run the plug to somewhere you can get to.

So the ultimate would be a block heater, wth oil pan, tranny and diff heater. Or even better, a heated garage.


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