Why is it still running cold?

[dizz]

318i m40
Changed the thermostat because it never got above 1/4 on the temp guage, but even with the new one in it wasnt much better, but now its got much colder, this morning on a 12 mile trip to work the needle didnt move, i did get luke warm air from the heater though.

1. is there anything else that could cause this
2. could the new thermostat be faulty

help, i leave the house at five o'clock (am) and its dam cold.

[johnono]

check brown sensor for integrity.

poor signal possibly, are u getting heat in the cabin after driving for a while?

if so then i suspect faulty sensor

[dizz]

I do get heat after about 5-10 mins but it never blows hot, can you tell me where the brown senser is, and does this send the temp to the gauge
thanks.

[johnono]

it does take time to really warm up, but if u can feel a decent heat from it in around 10 mins then uԚ´re alright jack.

the brown sensor

http://www.e30zone.co.uk/modules.php?na ... own+sensor

cant find a location pic just now, mabey some other kind zonie will oblige

[dizz]

Thanks johnono, but the best it will blow is luke warm after 25 mins running time (12 miles) should be better than that i hope.
So today i put some card infront of the rad to block the cold air rushing in, and after doing the same amount of miles it was on 1/4 and blowing hot.
when i changed the thermostat i got an airlock and it got very hot, almost into the red, could this have damaged the thermoastat in some way?

[Simon]

Have you got a faulty viscous, can you hear it wooshing constantly with the engine speed?

[m-dtech]

if its that bad disconnect the radiator and join the two hoses together

i ran an old car like that for a week

lol

[jonbuoy]

Have you got a faulty viscous, can you hear it wooshing constantly with the engine speed?

My thought's exactly

[dizz]

if its that bad disconnect the radiator and join the two hoses together

i ran an old car like that for a week

lol

lol, now theres an idea.

Could be a faulty viscous, but wont hear it wooshing because the top end rattle is too loud

when does it kick in and out is it heat/speed related?

[Simon]

if its that bad disconnect the radiator and join the two hoses together

i ran an old car like that for a week

lol

lol, now theres an idea.

Could be a faulty viscous, but wont hear it wooshing because the top end rattle is too loud

when does it kick in and out is it heat/speed related?

You should hear the viscous at anything above halfway on the guage, but if the viscous is faulty and running at all temps, it will keep the engine much cooler than it should be at this time of year especially.

[Simon]

Should have added, to test it, try and turn the fan when the engine is switched off and cold, it should turn with no resistance, if it's hard to turn then that's your problem.

[dizz]

Turned the viscous fan by hand this morning with the engine cold and it turned with very little resistance, when i started it up the fan started spinning does this mean its ok or not?

[Martinaston]

When the engine is hot the heat is transfered through the waterpump spindle into the fan viscous clutch (fluid) that then turns stiffer and spins the fan at the same speed as the engine, this then increases the air flow through the radiator and brings the temperature back down.

So yes, when the engine is cold the fan should spin with a slight resistance and be harder to turn after the engine has been used.

Are you sure you have bled the system properly ?
If you have a large air lock the sensors will not be immersed in coolant and give false readings.

When the engine has erm... warmed up give the hoses a squeeze to find out which ones are hot and to see if the system is over pressurised indicating an air lock, the pipes should still be squashable if it's at the right pressure

The temperature guage is not that accurate anyway so you may just have a congested internal heater matrix. (read the other threads on similar problems)

[dizz]

Ok, i think now that the viscous fan is ok and with the rad blocked off the heater blows nice and hot so the heater matrix seems ok too.
That just leaves a posible airlock, the top hose gets very hot and the bottom hose luke warm both are squeezeable.
i have done a search on airlocks (god this is a big problem with e30's) and have a few things to try tomorrow

[oze30]

On another note..

How do you bleed the system when you can't turn the bleed screw??

Oh.. And the reason mine took 18m and 30 mins to warm up???

I had no thermostat in there!

[rayman]

take the over flow pipe of the rad, block it off top coolant up until all the air comes out of the rad, put pipe back on rad when just coolant comes out and no air.