Last night I was driving and all of a sudden My car Over heated super fast. I turned on the heat and mild cold air. I dont understand then I let the car sit there untill it cooled down then started to drive again and it over heated super fast again. :mad :mad :mad :mad

I am thinking it is the Thermostat or antifreeze resevoir? I think it has broke, I believe there is no anitfreeze going to the motor. What I dont understand it how mild cold air would come out.

P.S The CF was taken off already I put the OEM hood back on.

Chances are good you have warped your head. Maybe not enough to cause a HG leak, but that remains to be seen. Definitely fix the problem -- cracked radiator, failed water pump, split or leaking hose, broken resevoir, or blown HG. Then do some testing to find out whether pressurized combustion air or engine oil is getting into the coolant or whether coolant is being burned up in the combustion chamber, any of which are due to a failed HG.

If all looks good, drive the car and watch carefully. The head could be warped and the HG may leak under boost. If so, it needs to be pulled and resurfaced and an new HG installed.

Cooling system maintenance on these cars seems to mean routine replacement of all parts.

Philip Bradley

<< I turned on the heat and mild cold air >>
That is what normally happens when you lose coolant..The HEAT gets luke warm or cold..because the system is airbound...
And Phil's post..per usual is right on the money....

I would just go ahead and replace the thermostat, water pump, and hoses first, refill coolant and bleed/check for overheating, replace radiator, check for overheating. At least if these don't work, you can eliminate the cooling system.

Sounds like a water pump failure to me. :dunno Symptom is classic of the plastic impeller failure. I don't know you would have one in your motor, but I'd bet that what it is.

Your head should be allright, as long as you shut it down as soon as it got into the red light district....

Have you recently drained your coolant? If so, it sounds like you did not bleed the air out of the system. there should be a phillips head plastic screw next to the filler bottle. When the car is up to temp, slowly unscrew the cap and you should see bubbles come out. That's all of the air that is trapped in the system. When no more bubbles come out, all of the air is bled. Let the car cool completely and fill coolant to the Koldt line on the filler bottle. That's the procedure for an e36 m3

Chas

Manuyc.. did the gauge needle hit the red? If so, for how long.. IF it simply headed for the hot land, odds are you didnt warp anything.. If it sat in the red for awhile, then I go along with what teh others said.

I had to leave the car in red light for a couple of min. When I got to my shop I filled it up with anti freeze and it ran fine, no over heating but the last night I was racing this cobra and it over heated in two seconds. I had seen where it was leaking from. the bottom of the resevore tank where the big hose leads to the thermostat cover. Now do you think it is the hose is worn, resevore tank failur, or the rad needs to be upgraded. I had recently change to two 10" spal fans also. It was working fine.. What do you think the symptom is?

I had to leave the car in red light for a couple of min.

:eek:
I thought that a couple seconds in the red was bad.

I actually like the CF hood btw.

I know it was bad to leave it in the red but I was on the highway and had no place to stop but at my shop.

Now do you think it is the hose is worn, resevore tank failur, or the rad needs to be upgraded.


First, Check to see if that hose is fully attached. I know mine came loose before and I was leaking coolant fromt hat exact same spot. Pushed it back on adn tightened it, problem solved, although for me even though it was leakign from there, the leak was higher and my system stil had enough coolant runnign through ti not to overleak. odd.

Second, check if that hose has any cracks or holes in it. Is the fan choppign into any hoses?

And if that still doesnt help then pull open your thermostat and see if that mechanism is working. It should be like a $40 part. If thats nto it then probably your water pump. Have you ever upgraded your water pump? The factory water pump has a plastic impellor blade in it that almsot always breaks by about 100k miles. Replace water pump with metal impellor pump.

If that repairs it then cross your fingers and try to inspect any possible damage from the overheating incident. Hopefully you remained off the boost once you noticed the heat.

And finally, it may be time to convince that significant other that a water temperature gauge (not the buffered out factory one) may be necessary to protect your investment in fun.

I will def check all those symptoms. How ever I have two 10" spal fans so ( the fan rubbing against the hose is out).

I believe it is the thermostat cause my car was sitting in the garrage for two months while the S/C was getting repaired. After it was repaired I started the car and it over heated right away. I noticed that no anitfreeze was getting to the other side. The theromstat was stuck So I poured antifreeze from the other end of the hose and it started to work. But I now I think it is stuck again so I should order another one but I will def check the hose under the resevore.

It could also be the switch inside the resevore it could be broken or stuck

My car only has 32,xxx Miles on it. Do you still think it is the pump. I do have a water temp guage but I am scared to drill into the block to install it. unless you have a better way of puttin it?

I will double check the hoses too Thanks for your insite fella's.. I will keep you posted.:buttrock

it can be tapped into a metal thermostat housing. z3s came stock with metal ones, right?

First, Check to see if that hose is fully attached. I know mine came loose before and I was leaking coolant fromt hat exact same spot. Pushed it back on adn tightened it, problem solved, although for me even though it was leakign from there, the leak was higher and my system stil had enough coolant runnign through ti not to overleak. odd.

Second, check if that hose has any cracks or holes in it. Is the fan choppign into any hoses?

And if that still doesnt help then pull open your thermostat and see if that mechanism is working. It should be like a $40 part. If thats nto it then probably your water pump. Have you ever upgraded your water pump? The factory water pump has a plastic impellor blade in it that almsot always breaks by about 100k miles. Replace water pump with metal impellor pump.

If that repairs it then cross your fingers and try to inspect any possible damage from the overheating incident. Hopefully you remained off the boost once you noticed the heat.

And finally, it may be time to convince that significant other that a water temperature gauge (not the buffered out factory one) may be necessary to protect your investment in fun.


After some time in 95 (S50), E36's...S52 engines.... no longer had plastic impellor waterpumps..
His car is a 2000..I believe....:)
Although I have seen later model water pumps fail early..it wasn't because of a plastic impellor...

I will def check all those symptoms. How ever I have two 10" spal fans so ( the fan rubbing against the hose is out).

I believe it is the thermostat cause my car was sitting in the garrage for two months while the S/C was getting repaired. After it was repaired I started the car and it over heated right away. I noticed that no anitfreeze was getting to the other side. The theromstat was stuck So I poured antifreeze from the other end of the hose and it started to work. But I now I think it is stuck again so I should order another one but I will def check the hose under the resevore.

It could also be the switch inside the resevore it could be broken or stuck

My car only has 32,xxx Miles on it. Do you still think it is the pump. I do have a water temp guage but I am scared to drill into the block to install it. unless you have a better way of puttin it?

I will double check the hoses too Thanks for your insite fella's.. I will keep you posted.:buttrock


I did not want to use my aluminum thermostat gooseneck as the spot for my sensor for my Autometer water temp gauge....

So I called Autometer, and they sent me **I believe** a 12mm x1.5 sensor, that is used as a temp sensor on A LS1 Chevy head....

On the psgr side of out engine block, near the rear, we have a drain plug ..to empty the antifreeze from out engine block...I removed the drain plug, and thread this sensor into the hole..IT fit perfectly....

And it works perfectly..:)

nice! that seems like a much better way to go.

nice! that seems like a much better way to go.


Yes..I have driven Autometer whacky..I have 7 Phantom gauges in my car, not including my WB and narrow band Split Second unit...
I think every Autometer gauge I have, I have done something different..to make it fit and work the way I want...:)

Dam man I did blow my gasket. I am getting it fixed. tans for everyones help.

n/p. what caused it? or will you know when they change it?

good luck and sorry to hear.

I am not sure yet I am gonna put the thermostat in today and find out if that is the case. I had put my 12 PSI pulley kit in and the m50 intake manifold. But didn't put in my head Gasket to lower the compression I was to lazy to put it in. So I think that could have blown it deff.

I changed the resevore and that is fine.