high oil temperature

[torpedo]

Hi, I am new to this forum. But I've been driving my 02 325i for about 2 years now. It has 25000 km on it.
My concern is oil temperature is sometimes higher than the middle. The needle is about 5 degrees to the right of the centre. Has anyone else seen this? It's not always like this, only occasionally, but I am worried.
About 6 months ago, I noticed high oil temperature is slightly above normal. I went to the dealer, they found engine oil is 1 L less than normal, so they topped it up. The problem seemed to have gone away for a while. But a month later, it came back. This time, it's coolant, so I topped up coolant myself. Soon after, "Service Engine Soon" warning light came on. And the dealer replaced a"secondary air pump & divertor valve" under warranty. Since then oil temperature has been normal.
Just about two days ago, I started noticing high oil temperature came back! When I asked dealer, they checked sensor and found no problem. They just told me if you are driving in slow traffic, it's normal for oil temperature to be a little higher, all I have to do is to turn up heat and open windows. Is this normal?? what potential problem could it be?
I'm hoping someone has experienced similar problem and found root cause would help me out.
thank you.

 

[bmwrocks]

I am a little confused here.....BMWs from MY '02 don't have oil temp guages!!! At least not the ones in the US, do they have them in Canada??

Do you mean coolant temperature?

You should NEVER have to turn up the heat and open the windows to cool off the coolant!! In fact I think this would have little effect on lowering the overall coolant temp, as the heater core accounts for such a small volume of the overall coolant volume. Your radiator in conjunction with your thermostat is supposed to dissipate engine heat.

It sounds to me like you may have some blockage in your coolant system. Likely in the lower half of your radiator. Have you had your coolant drained and changed in the vehicle ever? If not, you are supposed to do that every two years I think. Make sure they drain not just the radiator, but also the engine of coolant as most of it is in the engine. If nothing else is wrong, then this may help. You may also have a bad thermostat which would also cause the engine to run warm.

 

[torpedo]

sorry, my mistake. coolant temperature gauge

 

[aNoodle]

Definitely something is wrong.

The radiator temp guage isn't a true temp reading...meaning it doesn't vary really if it is within a range of an acceptible operating temperature. My needle never moved off center even when driving through Death Valley during summer! One would think it would edge up a bit when the outside temp is 120+. But it didn't because the temp was within an acceptible range so the needle just registered straight center. (I've only seen my needle above center when I got air pockets in the system after I flushed the radiator....don't ask, I learned when they say pour slowly....they actually mean SLOWLY!!)

Maybe it's a faulty guage?

Actually, bmwrocks, I think you can dissipate a good deal of heat from the cooling system by turning the cabin fans on full blast and turning the temp on high (a good idea if the car is overheating...especially when the car isn't moving). When a car is overheating I've always been told to open the hood and leave the car running if possible (roll the windows down, turn the heat up and fans on high), becuase that will keep the water flowing and fan moving over the engine. Is this bad advice for our BMW's?

 

[aNoodle]

One other thought...may be too obvious. You've checked your radiator fluid level, right? During my spring cleaning I had to top mine off with about 1/6th of gallon. I was surpised how much it had dropped over the winter.

Anyway, you obviously don't want to lift the radiator cap until the engine is completely cold and you're on level ground. You'll want to stick to the 50/50 mixture of antifreeze, but if you're not adding alot, then some straight distilled water won't be too bad.

 

[bmwrocks]

Actually, bmwrocks, I think you can dissipate a good deal of heat from the cooling system by turning the cabin fans on full blast and turning the temp on high (a good idea if the car is overheating...especially when the car isn't moving). When a car is overheating I've always been told to open the hood and leave the car running if possible (roll the windows down, turn the heat up and fans on high), becuase that will keep the water flowing and fan moving over the engine.

Thanks for straightening me out. I did not know this good piece of advice. My comment was based on logic, not knowledge......

I still think torpedo needs cooling system service if he has not already done so. And the stat may very well be bad too, but the service is good preventive maint, and may help to clean out his system.