RE: Engine running VERY COLD

["Fadeev, Alex" <Alex.Fadeev@xxxxxxxxxxxxxx>]

> In my memory, My 95 M3 used to run with cooler temp
> reaching midpoint; this fact is changed after I
> pouring 2 complete bottles of Prolong Engine Treatment
> into my engine. In the beginning the cooler temp really
> showed lower than midpoint(3/4 to midpoint)and I
> thought it should be the effect of Prolong that giving
> the engine better lubricant. 

Paul,
That's highly unlikely, IMHO.
Regardless of your oil, a properly functioning cooling system will try to
keep your engine at the operating temperature. That means a closed
thermostat to heat the car up asap, then a variable open thermostat to keep
the engine from overheating.

> However, the engine temp is getting lower and lower and
> long time I haven't seen it reaching a quarter point (1/2
> to midpoint); Recently, here in Montreal is almost
> winter and the engine is running even colder no matter
> how long your driving, the temp meter always stops at the
> right end of blue square mark(full cold).

It sounds like your thermostat is stuck open. 

> I haven't changed engine oil yet, the oil with Prolong
> has been using for 3000 miles. I know this is unusual,
> but what's your guys opinion? 

If you know better then BMW engineers, feel free to change the engine oil as
often as you please. 
Otherwise follow the SI lights.
I will refrain from commenting on 'Prolong'.

> How do I check if the thermostat of my car is function
> ok or not?

On an E30, it's a 5 minute job to remove the thermostat. 
If it's open when you remove it, it's dead. A replacement should be in a $20
range. Then you can literary boil it on a stove and see when it
opens/closes. E30 80F thermostats are supposed to start opening at 80F and
be fully open by 100F.

alex f

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