Car overheating and no heat in cabin.

[NeoTek]

I am waiting for the tow truck because my car overheated and blew a radiator hose. Anyone have any ideas as to what the problem could be? I was getting no heat in the cabin for the past few days and then the car started overheating. Thanks!

[M-technik-3]

Thermostat.

[NeoTek]

Thanks! So I got the car home and the radiator hose neck broke off. So it looks like I am in the market for a new radiator and thermostat. Is there anything else I should take a look at while the radiator is out? Would anything else cause the car to behave like it did?

[jszy25]

Do the thermo housing, the water pump, new expansion tank, all new hoses and a full, fresh coolant flush. Make sure to use the BMW coolant. Might as well get a new fan clutch while you have it off.

[M-technik-3]

Or go electric fan. If you plan to keep the car any length of time you might want to consider getting an aluminium radiator. The OEM fail about every 3-5 years anyway. Plastic endcaps are crap.

[Skunk]

Check bimmerzone's threads in the group buy section for parts. I think they have a entire cooling sys. package for sale on their site.

[mipktb]

Make sure you get an aluminum thermostat housing, BTW.

The early OE plastic ones are garbage.

[E36TitanM3]

You overheated, did the needle go into or close to the red? you might want to make sure your didnt blow your headgasket or warp your head too. Once you replace everything, check for oil in your coolant or coolant in your oil

[Moron95M3]

You overheated, did the needle go into or close to the red? you might want to make sure your didnt blow your headgasket or warp your head too. Once you replace everything, check for oil in your coolant or coolant in your oil

+1 hope not though

[desynch]

if you don't see anything in either case, compression test it

[bmw4wmb]

I just swapped in a Mishimoto aluminum radiator on Monday since my radiator neck had cracked. I've had the car a while, so I'm on my 4th radiator (if you count the original). I went aluminum this time because there a a few affordable ones around now and they can cost the same as the Behr OEM ones. I've done the cooling system a few times, so if you have any questions feel free to PM me.

As everyone is mentioning, it is a good time to do the h2o pump, t-stat, and metal t-stat housing. Hoses and belts would be good now too. I also opted to do the FDM and install a SPAL fan but it didn't arrive in time. Right now I am still running with fan clutch/grenade device. Hopefully I'll have time to put the SPAL on in a few weeks.

Also, as for the lack of heat in the cabin, that can happen when there is air in the system. I normally encounter this after I've done my repairs, added coolant, and am bleeding the system. Once it is properly bled the heat starts working again.

[sbblowz]

contact cmuzzy he will sell u a kit for 250 shipped that includes everything

[NeoTek]

Well I replaced the radiator, t-stat and belts. That was all I could get locally and put in today. I did pull the water pump which was the metal one and it looked fine. Unfortunately my car is still overheating. Any ideas what it could be?

I did notice that the left hose (passanger side) coming out of the t-stat housing was not hot at all and the right one was extremely hot. Would that give me a clue as to what the problem is?

Thanks for all the help, any more advice is greatly appreciated.

[Moron95M3]

did you bleed the system? also, did you test your t-stat in boiling water first?

[desynch]

Well I replaced the radiator, t-stat and belts. That was all I could get locally and put in today. I did pull the water pump which was the metal one and it looked fine. Unfortunately my car is still overheating. Any ideas what it could be?

I did notice that the left hose (passanger side) coming out of the t-stat housing was not hot at all and the right one was extremely hot. Would that give me a clue as to what the problem is?

Thanks for all the help, any more advice is greatly appreciated.

That usually happens when you haven't bled it...or you didn't do it properly.

[NeoTek]

I bled the system using these instructions from another forum post on here.

- put the key in the on position (car off)
- set the temp to the hottest
- remove the bleed screw and radiator cap
- take time to refill the expansion tank.

- And THEN get in the car turn the car on rev it up to ~3k and hold it there for a few seconds with the radiator cap off and the bleeder screw off
- get out the car and take time to refill it again to the top
- replace the radiator cap on tight
- replace the bleeder screw but do not tighten it
- get back in the car and hold it at ~3k one more time until you see coolant coming out of the bleeder screw with NO BUBBLES
- get out of the car and tighten the bleed screw

drive the car for 15 mins to properly warm up, let it cool down and check the level of coolant

It's still overheating. I am still not getting heat into the cabin area of the car, even when the engine starts to run hot. Could it be the fan clutch? I haven't had the courage to drive the car around and when it overheated the first time I was sitting in traffic.

Ok, new update. I drove the car for about 1/4 of a mile to see if it was just overheating on idle. Started to overheat immediately. Got it back home and took off the top radiator hose that connects to the t-stat housing. It was hot but completely dry inside. Inside the t-stat housing appeared to be completely dry as well. What do you guys think, water pump or something else?

[M-technik-3]

I don't think you have filled the system totally. How much distilled water and coolant did you use?

No need to get in vehicle the TB is right there on the intake you can press it down and watch the coolant level drop. I find it's easier to bleed the system when you are on a slight as in 3 2x10 home made style ramps so the front allows air pockets to come out faster.

[thejlevie]

While overheating and a loss of heat could be due to multiple failures (e.g., bad thermostat and bad heater valve), overheating and no heat suggests that coolant isn't flowing or that the heater core and at least a portion of the head is filled with air. Extremely low coolant will cause this, but there are other possibilities. On an early M3 (though 95) with the original pump a failure of the plastic impeller is a possibility. Impeller failure on later production with the composite impeller is extremely unlikely.

An air bubble in the cooling system can cause the loss of heat, and if big enough, overheating. If there has been recent cooling system work, the air may be just from a failure to fully bleed the cooling system. In the absence of recent cooling system work, the cause of an air bubble forming in the cooling system will be the result of a head gasket leak. If the car has a past history of cooling system problems and overheats, the chances of a head gasket failure are quite high.

A simple test for a leaking head gasket is to fill and fully bleed the cooling system (procedure below). Then drive the car for a bit (but don't allow it to overheat) and re-bleed. A significant release of air then or on a subsequent bleed is evidence of a leaking head gasket. A shop test for a leaking head gasket is to monitor cooling system pressure with a sensitive gage while pressurizing each cylinder with 180psi for several minutes. A negative result on a cold engine requires that the test be repeated on a hot engine.

1) Using ramps or a jack get the front of the car 1' or more higher than
the rear. That will make the radiator and bleed screw the highest point
on the engine and facilitate removal of air.

2) With the bleed screw open, add coolant until no more air comes out of
the bleed.

3) Leave the filler cap off, or at least loose, and set the heat for max
temp and fan speed. Leaving the cap loose will prevent air that's still
in the system from causing a "coolant fountain" once the engine heats
up. Start the engine and allow it to warm up to operating temp. As it
warms up occasionally crack the bleed screw to release any air and top
up the coolant as necessary.

4) Once the engine is at temp bring it up to 2000-2500 for a few seconds
several times. Then crack the bleed until no more air is released. At
this point the heater should be throwing lots of hot air, which
indicates that the heater core is filled with coolant. You may have to
repeat this a few times to get all the air out.

5) Drive the car a bit, allow it to cool back down, and recheck the
bleed for air. Over the next few days you may get very small amounts (a
few bubbles) of air out of the bleed screw.

[amdspitfire]

Don't listen to all the (^crap) you probably just do not have enough coolant in there..

-dont turn on the car, just turn the key to the last position
-turn the heat on
-open bleeder screw
-keep adding water/coolant mix to the expansion tank until it starts flowing with out bubbles out of the bleeder screw hole

[the fly]

change the water pump!

[VonDeLinde]

water pump had same issue 100%

[NeoTek]

Don't listen to all the (^crap) you probably just do not have enough coolant in there..

-dont turn on the car, just turn the key to the last position
-turn the heat on
-open bleeder screw
-keep adding water/coolant mix to the expansion tank until it starts flowing with out bubbles out of the bleeder screw hole

This worked completely. I removed the bleeder screw and filled it up until the coolant level reached the top of where the bleeder screw goes. Worked out any bubbles and it's good to go.

Thank everyone so much for the help. Now I just need to keep an eye on it to make sure I didn't blow a head gasket or anything.

[MThrizze]

if you really want to be sure just do a compression test, i highly doubt you damaged anything though

[amdspitfire]

This worked completely. I removed the bleeder screw and filled it up until the coolant level reached the top of where the bleeder screw goes. Worked out any bubbles and it's good to go.

Thank everyone so much for the help. Now I just need to keep an eye on it to make sure I didn't blow a head gasket or anything.

you won't believe how much shit I went through on so many diff cars till I "figured" out that I was underfilling the cars always.

[Jeffro L]

Don't listen to all the (^crap) you probably just do not have enough coolant in there..

-dont turn on the car, just turn the key to the last position
-turn the heat on
-open bleeder screw
-keep adding water/coolant mix to the expansion tank until it starts flowing with out bubbles out of the bleeder screw hole

...I jacked around with my car for 10 hours before reading this previous post...10 minutes later and my heat is working again and the car's not overheating. Thanks man, you're a lifesaver!!!