No Heat! - BMW Forum

kylek325i · 01-27-2006, 02:55 PM

I just replaced (50 miles ago) my thermostat and the gaskets with it, and now I have no heat out of my vents. ALSO right after i replaced it i drove the car for about an hour and a half, and then popped the hood and found a mess of coolant. it is splattered on the underside of the hood, and on top of everything on the driver's side of the engine bay (like the fan had splattered it?). SO, I immediately thought thermostat but there is no sign of leakage at all around the the housing or either of the hoses coming off the housing. Didn't see any obvious leakage on the ground. Fuses are fine. Faulty thermostat? I don't think so, because the temp had previously been overheating/ fluctuating, and that whole ride the needle remained dead center of the gauge and didn't budge. WTF is wrong????

Dirty_Tool · 01-27-2006, 03:57 PM

Did you bleed the cooling system well after doing the repairs?

DT

GranitSilbur · 01-27-2006, 07:09 PM

Either you have a faulty expansion tank cap or there is a crack in the radiator neck. There is no heat because of the leaking coolant. Air gets in the system therefore no heat.. Check those 2 things first.

BMWJNKY · 01-27-2006, 09:22 PM

Quote:

Originally Posted by GranitSilbur

Either you have a faulty expansion tank cap or there is a crack in the radiator neck. There is no heat because of the leaking coolant. Air gets in the system therefore no heat.. Check those 2 things first.

Wow.

You can have a bad cap and a leak in your cooling system but your heater will still work. Like Danny said, sounds like the cooling system wasn't bleed enough and air got into the system.

kylek325i · 01-28-2006, 10:11 AM

hmmm thanks ill bleed it and see what happens.

93 325i · 01-28-2006, 10:59 AM

The alarming thing is the coolant everywhere.. if there is a bad cap or cracked neck that causes the air to enter the system, therefore no heat.. i'd worry about the coolant going everywhere issue before bleeding, then once u solve the leak by all means bleed the system and you shouldl have your heat back

BMWJNKY · 01-28-2006, 02:09 PM

Quote:

Originally Posted by 93 325i

The alarming thing is the coolant everywhere.. if there is a bad cap or cracked neck that causes the air to enter the system, therefore no heat.. i'd worry about the coolant going everywhere issue before bleeding, then once u solve the leak by all means bleed the system and you shouldl have your heat back

If you don't properly bleed a system and have air in it, it will cause hot spots in the cooling system and cause an overheating situation. When it over heats coolant will come out of the system from the overflow port by the cap. Also, the cooling system is normally under pressure, not vacuum. Thusly, if there was a crack coolant is going to be forced out, and air would not be sucked in. You should take some automotive classes so you quit spreading wrong information arround.

GranitSilbur · 01-28-2006, 04:15 PM

If you read the original post carefully it didn't overheat while there was no heat.. So what would cause the coolant leak then? AN improperly bled system will cause overheating (first hand experience)...And think about when you turn your car off and it cools down.. this process of contracting could definetly suck in some air if there was a crack (hence the system doesn't stay pressurized when cool).. My point is he wouldn't have gotten too far with an improperly bled system. Before you start questioning one's automotive knowledge you should get all the facts first.