Cooling Sytem HELLPP!! - BMW Forum

PharaohKwazi · 03-06-2009, 09:16 PM

First off we will do this in point form

I'm driving my 325 and the engine start to go to the red mark so i turned it off the on board computer said coolant low so i added more still overheating and now it is leaking coolant
called my bro he ask where it was leaking from it was around wear the thermostat hose was he told me that it was the thermostat so i changed the thermostat and flushed the system but was not able to bleed system properly
now i'm driving and i see radiator fluid leaking from the plastic part of the radiator from a little hole that the thermostat hose is hooked too fixed that problem
asked bro and he said that i might of not positioned thermostat properly so I redid the process and put it properly
so now i'm trying to bleed the system and there is no bubbles or coolant coming out of there I'm I bleeding it wrong or what else can be wrong
And PS it was my bro car before and the heater was not working before he gave it to me

johnnyBgood · 03-06-2009, 09:39 PM

Quote:

Originally Posted by PharaohKwazi

First off we will do this in point form

I'm driving my 325 and the engine start to go to the red mark so i turned it off the on board computer said coolant low so i added more still overheating and now it is leaking coolant
called my bro he ask where it was leaking from it was around wear the thermostat hose was he told me that it was the thermostat so i changed the thermostat and flushed the system but was not able to bleed system properly
now i'm driving and i see radiator fluid leaking from the plastic part of the radiator from a little hole that the thermostat hose is hooked too fixed that problem
asked bro and he said that i might of not positioned thermostat properly so I redid the process and put it properly
so now i'm trying to bleed the system and there is no bubbles or coolant coming out of there I'm I bleeding it wrong or what else can be wrong
And PS it was my bro car before and the heater was not working before he gave it to me

This might help......

It really helps to have a friend lend a hand by sitting in the car revving the engine and keeping an eye on the temp gauge. Start off by removing the coolant reservoir cap and the plastic bleeder screw right next to it. Fill the coolant reservoir with a 50/50 mix of coolant and distilled water. Have your friend start the car, turn on the heater to full hot on the vent position and rev the engine to about 2500 RPM, if the temp gauge goes past the 12 o'clock position, shut the engine off, let it cool down and start over again. Watch the coolant reservoir, as the engine warms up the coolant level should drop, refill as the coolant is sucked out of the reservoir. Watch the bleeder screw hole also, when coolant with no air bubbles begins to overflow then you're almost done. It's a good idea to have some paper towels handy to mop up any overflow. Screw the bleeder screw back in (be careful to not break the plastic screw) and continue to rev the engine, you should see a continuous stream of coolant spraying in to the reservoir from the small hole at the top. Continue letting that spray in to the reservoir while your friend revs the engine for a couple of minutes, until the gauge hits the 12 o'clock mark, to ensure any remaining air is gone. If the heater is blowing hot air when you're revving the motor AND when the engine is at idle then your cooling system is properly bled. If your vents are blowing cool air at idle then you still have air in the system, try revving the engine more and/or squeeze the radiator hoses to help dislodge any trapped air. Once your system is fully bled, top off the reservoir and replace the cap. Check the coolant level in a day or two and top off as needed.

How To BMW

garbone · 03-06-2009, 11:15 PM

+1 for johnnybayonne

sounds like the system needs to be bleed properly. make sure all hose clamps are tight.

also. be weary of the upper hose fitting on stock radiators. they tend to break. also is your thermostat housing plastic? back when i had my coolant leak i found a small crack on my thermo housing and have since replaced it with an aluminum one.

marti5 · 03-07-2009, 03:03 AM

If it still over heats after all the above, waterpump.

PharaohKwazi · 03-10-2009, 09:52 PM

OK thanks guy I've done the top suggested stuff but when i tried to bleed the system it kept sucking up the coolant, then alot of steam came out of the bleed hole, the reservoir started to bubble and overflow and engine overheat

i turned it off and let it cool down then started again, this time i put the reservoir cover on and the coolant started shooting out, I turn it off and tried the other process again, as it happened before my car started to overheat

What should I do now??

johnnyBgood · 03-10-2009, 10:32 PM

Quote:

Originally Posted by PharaohKwazi

OK thanks guy I've done the top suggested stuff but when i tried to bleed the system it kept sucking up the coolant, then alot of steam came out of the bleed hole, the reservoir started to bubble and overflow and engine overheat

i turned it off and let it cool down then started again, this time i put the reservoir cover on and the coolant started shooting out, I turn it off and tried the other process again, as it happened before my car started to overheat

What should I do now??

Do you know if the original water pump is in the car....what's the mileage?

If the original water pump is in the car, they are known to fail due to its plastic impeller that breaks apart. If this happens, the water pump will not circulate the coolant thru the system, causing the system to overheat...

u n d e r s t e e r . c o m

PharaohKwazi · 03-11-2009, 01:17 AM

im not sure about how much mileage but there is 142 915 miles on it

basrite · 03-11-2009, 10:02 AM

Its kinda scarey how many times its gotten to that temp.. be very careful as you can warp the head!

Is there steam/water vapour coming out the exhaust?

J.

PharaohKwazi · 03-11-2009, 09:18 PM

a couple of times do you think i should change the water pump ?

johnnyBgood · 03-11-2009, 09:50 PM

Quote:

it kept sucking up the coolant, then alot of steam came out of the bleed hole, the reservoir started to bubble and overflow and engine overheat

This is telling me that the system is not circulating, so either the t-stat is stuck closed (defective)......but you say it is new & installed with the arrow or dot @ the 12:00 o'clock position......so I would replace the water pump, with 140,000 +..... it is about due again, if it was even replaced initially....

bimmerzone.com
BMW parts for your 3, 5, 7 series

AAA:GRA G3000-150188 Water Pump Metal Impeller $ 65.53
get your upper & lower radiator hoses too, over $75.00 ordered free shipping

johnny,

PharaohKwazi · 03-12-2009, 05:23 PM

thanks alot im going to try that

marti5 · 03-13-2009, 05:46 AM

I did tell you 5 days ago it was the water pump!

Texbeamer · 03-13-2009, 10:23 AM

Quote:

Originally Posted by marti5

I did tell you 5 days ago it was the water pump!

sam1977 · 04-04-2009, 08:04 AM

Hi Marti5 - I read these posts with interest. I see you have an E38 and my question is concerning one of these but is a similar problem to the 3 series discussed here. I hope you might be able to help me.

I have replaced the expansion bottle since it was cracked and leaking coolant. I filled the cooling system with the bleed screw and cap off and engine running. However before all the air bubbles disappeared from the bleed screw hole, the whole thing erupted from the top of the expansion tank. Next tried filling it again after cooling down, put in about 8 litres of cold coolant, same thing again. Put radiator cap on after filling system, bled out air and then closed bleed screw. Next thing, pressure in system overcame expansion tank cap and let go all the coolant. All throughout this the temp gauge is sat in the middle where it always is.

Mechanic with me tells me "Oh dear, thats a head gasket failure". ???!!!????!!!! ... and wants £2000 for fixing it ... double ???!!!??? He says that the reason the water is erupting is because of pressure from one or more cylinders. Call be sceptical but: doesn't overheat, no oil in water, no water in oil, no rough idle, runs smooth as silk, no steam from exhaust, no smell of gasses in expansion bottle ... however the heater isn't running hot even at max fan and 32 degrees set which is supposedly a classic head gasket humdinger.

To me it sounds like maybe a) system has airlock in which case what am I doing wrong bleeding it or b) water pump is knackered. The pump is making a bit of noise and watching it from above runs out of line every now and then. I've already ordered a new pump but also expansion tank cap and t-stat just in case. These are being fitted on Monday.

Can anyone help. The last thing I want to do is spend £2500 on a bloody head gasket replacement unless I am sure thats what it is. I am in Gibraltar so we don't really have any high-tech BMW diagnostics here to do anything. The car is a 2000 740i.

Thanks, I hope you can advise me

marti5 · 04-04-2009, 10:37 AM

You do not have the cap OFF and car running!!!!, this is why you have a volcano !!!

best time to do this is 1st thing in the morning

1. Ignition on pos II ( DO NOT START)

2. airco on MAX heat..... blower to LOWEST setting

3. open bleed screw

4. put the coolant in very slowly with the screw open and keep filling until the float becomes level with the top of the thread.

5. replace cap and screw close the bleed screw.

6. start up....leave 2 minutes

7. cap off, check level add as needed

8. check again when engine is stone cold this is they only way to get the correct level reading.

Thats basically it, the best time to check the level is when the engine is stone cold, when checked if the float is way down, repeat as above, if only half down or so just top up until float is back level, it may take a few days to get right or happen instantly, but it will happen. It took me 2 weeks to get mine so that the float was at the right place every time I checked, but it was only ever down a little.

If however your "coolant level low " appears whilst driving then you will have to add some( but wait a while for the engine to cool a bit or you could crack a head!) regardless where the float is , just to get you home,then sort it later as above.