car running cold...

[e30fr3@k]

my car always runs really cold...the needle never makes it past 1/4 of the way up. i was wondering if running it at this temp is in anyway bad for the engine. my dad told me it was bad, but he drives an old accord =) what does he know

 

[Auslander RML]

I had a 318i that had the same issue, come to find it was a defective thermostat (duh!) I would assume that if you let the car idle till it gets out of that "blue" and keep the revs low, it would be okay...Do you get any heat out of the vents?

 

[e30fr3@k]

ya, i know it's the thermostat and i looked in my shop manual and it says you have to drain the coolant entirely. my mechanic is saying that my radiator is "used to" some lowsy coolant (lowsy meaning it's mostly water, i suppose), and he says that by draining the system and replacing it with new coolant, the radiator might not work properly, and thus "create a 300 dollar problem." i tend to drive with a heavy right foot, so it's hard for me to tell if i'm keeping it at "low revs" but i keep it below 3500 RPM until it gets out of that low range, and about 1/8 of the way up the meter(1/2 of the way up to itsnormal operating tempurature). if what my mechanic is saying is true about my radiator, then i would like to, at all cost, avoid replacing my thermostat. however, if i'm damaging my engine, somebody tell me! it's at 204k right now and running strong, but i'd like for it to remain that way. thanks.

 

[mjbst111]

Your mechanic has an interesting theory... seems pretty ridicules to me. Your radiator would like nothing more than new antifreeze. Drain it, put a new thermostat in and refill with 50/50.

If you had mostly water in your car, it would be evaporating and would need refilled from time to time. Your system would be getting corroded much quicker and now would be the best time to put new fluid in there.

As long as you are out of the blue you should be fine, but you need a new thermostat if your temp is wrong, it takes much longer to get out of the blue (if you ever do) with a stuck open thermostat, and that is not healthy for your poor bimmer.

 

[jrt67ss350]

Same mechanic that can't find the cracked exhaust manifolds he said were there before?

Yes, if you are running mostly water in the cooling system, or the coolant is old, you should change it. Coolant doesn't just lower the freezing point and raise the boiling point, it also lubricates the water pump and has corrosion inhibitors to prevent the radiator from corroding and clogging up.

I replaced my thermostat with a new one last summer (car was running hot in traffic and too cool on the interstate) and the operating temp according to the gauge is just a little higher than the 1/4 of the way up. The car reaches that temp pretty quickly, but never goes above it.

If you have doubts, change the thermostat. It's cheap and easy. Sounds like you should replace the coolant anyways.

 

[e30fr3@k]

Same mechanic that can't find the cracked exhaust manifolds he said were there before?

Yes, if you are running mostly water in the cooling system, or the coolant is old, you should change it. Coolant doesn't just lower the freezing point and raise the boiling point, it also lubricates the water pump and has corrosion inhibitors to prevent the radiator from corroding and clogging up.

I replaced my thermostat with a new one last summer (car was running hot in traffic and too cool on the interstate) and the operating temp according to the gauge is just a little higher than the 1/4 of the way up. The car reaches that temp pretty quickly, but never goes above it.

If you have doubts, change the thermostat. It's cheap and easy. Sounds like you should replace the coolant anyways.

ya...same mechanic. he's a friend of mine so i get free or cheap labor =) thanks for making my repair list even longer guys ...but seriously, thanks for the help-it comes much appreciated.