Engine running cold?

[bimmergalnj]

94 e34 525 temp issues. Noticed last week when it was freezing out that the temp guage would not make it to dead center and thought it was weather related. For the past two days, the guage gets barely above the blue mark, except at idle when it moves closer to center. At idle it actually jumps around a bit. Could my thermostat be stuck open or failed? Is it ok to drive it like this for a few days until I can get it to a mechanic? Other contributing factors could be type of driving: outside sales so stop and go every 5 miles so oil never gets warm, overdue for oil change, constantly running on fumes.

[grave77]

well it's ok to drive it this way ( would go change the thermostat as it seems stuck open ) but don't drive it hardly cuz the engine pistons will be warn out faster than usual.
oil will perform better in cold but as I said before don't drive it hard. by the way make sure the engin is warm when u start driving gauge is just pointing above the zero means that its getting warmer.

[632 Regal]

It shouldnt kill the engine for a couple days however it will cause harm in the long run as the pistons dont expand enough and it will chatter a bit in the cylinders obviously leading to accelerated wear. You probably have a thermostat that doesnt close completely.

[grave77]

True ... But what would be your comment if the car performs extremly better in cold, I mean something like 30% better than normal? would you say that the engine compression is very low in normal conditions? or any other ideas ( talking about the 6Cyl-535i engine )

[Derek A.]

Get a new thermostat. M50's run very rich when cold. You are burning a ton of extra fuel by not having the car at least get up to temperature. When you have the thermostat repalced get an aluminum thermostat housing. The plastic ones crack and fail all the time. As long as its in - get your oil changed !

[bimmergalnj]

thanks for the input. I am just nervous abt it bec the thermostat blew on my e28 and toasted the motor.

[bimmergalnj]

I am curious about something you guys said about driving the car. I HAVE to get to work tomorrow morning so I need to drive the car. I have not turned it on since I got home from work on Friday because I cannot afford any more major mechanical problems. I know long term I could damage the cat amongst other things, but will driving her for the next few days with the temp needle at abt 10 o'clock cause me to damage the motor? I had a reverse problem with a thermostat on my beloved Helga (e28) that resulted in a blown motor so I have the willies when it comes to temp guages. Driving the car involves about 15 miles of non-highway driving to the office and then stop and go traffic on rt 9 to see clients. Please share your thoughts.

[632 Regal]

you wil be OK just do not rev it up, drive slower than my grandma.

[bimmergalnj]

THANKS for getting back to me. Just curious (or perhaps annoying u with questions) but your comment abt driving slow....is that just so I do not put undue load on the motor? Also how slow does your grandmom drive.....I mean I live in NJ.....the road rage capital of the USA :)

[philbyil]

Sounds pretty typical for short distance, stop and go cold weather driving....these motors run pretty cool. However, that said, if you haven't replaced your water pump/thermostat/thermostat housing by now, this is a good time to do it!

Don't forget to use BMW anti-freeze and you can order all the parts from BMW. If you aren't handy with a wrench, this isn't a difficult job for most amateur wrenches or most shops.. shouldn't cost more than a couple hours work.

[632 Regal]

you may need to run the 4 way flashers till you get this fixed.

[bimmergalnj]

Did feel like I needed the flashers! It was just the stat. Seemed prettyu certain of it as well because of the temp getting to normal in traffic until I put on the heat. So glad to have warm toes again. Also got the oil changed so she is driving like a champ....except for failing inspection....post to follow cause it is an electrical question. Unfortunately I have about enough tools at my house to hang a picture......and not too much knowledge but looking to learn.