Author Topic: 1993 318i se e36 m42 - cooling system problems (Read 3510 times)

djmitsilee · « **on:** March 09, 2009, 04:29:26 PM »

Hi there,

This is my first post on m42club.com, great site, lots of help :-)

Before I start let me say that i am NOT a mechanic so if i've done something wrong please DONT shout at me, lol.

OK then, here goes ... after spending the winter on the drive I have decided to get my BMW back on the road for the summer, she is an old girl and in need of a little love, care and attention but being my first BMW i love it and wouldn't part with it for the world !!!

I started her up for the first time last week, and apart from the obvious flat battery, which i expected, she seemed to fire up ok, she was a little rough for the first 5 minutes or so and spluttered a little, again what i expected.

After she coughed and spluttered for 5 minutes and became awakened from her winter in hibernation she seemed to be running like a dream ...

I'll give her a good wash i thought to myself, so out came the bucket and sponge and i set about washing her ... by the time i had washed half the car i noticed she was getting warm and starting to smell a little ...

SUGAR, the temp guage was in the RED, i immediatley turned the car off and checked the water levels, yep you guessed it, empty resevoir tank, yeah i know, i should of checked the water levels first, b4 anyone starts, lol.

The car must of ONLY been running for 10 - 15 minutes MAX so i don't think the cylinder head or gasket had been damaged ...

I topped up the resevoir tank, and left her running to gain some charge in that dead battery, everything was OK. The car has been used now for a week with NO problems, until last Friday !!!

Last Friday we had to run an errand to a local town down the motorway about 30 miles round trip, this was the first proper run we did in it. All seemed to be ok, when we got home my Mrs said she would get me and the family a chippy and drove to the local shops to pick up the food ... when she came back she said she was sat outside the shops waiting for the food to be prepared with the car switched OFF, when she heard a loud BANG and steam was coming from the bonnet ...

She drove the car home, which I did shout at her for, and i popped the bonnet to have a look, immediatley i saw hot water all over the engine and noticed that the top rad pipe was loose where it went into the head, the plastic water flange that the pipe went onto had snapped. I replaced the part on the Saturday morning for a small cost of �11.40, i topped the resevoir tank up and took her for a spin around the block. When i got home i again checked the resevoir tank, which i found was EMPTY, and filled it back up again ... all seemed OK.

The heating on the car wasn't working and hasn't really worked properley since i brought the car out of hibernation, im assuming this is down to the water issues

The car seemed to be OK Saturday, Sunday and Monday (only small mileage).

I have just gone to visit my family down the road and noticed that again the temp gage went into the red !!! I stopped the car and allowed it to cool right down before crawling back home to safety. Water levels in the resvoir tank were OK. Out came the laptop and a little bit more investigation led me to believe that the cooling system needed bleeding. I unscrewed the bleed valve next to the resevoir tank and let all the bubbles of air out until i had ONLY water coming out and again filled the resevoir tank to the correct level !!!

I started the car up and let it get to normal running temperatures i.e. 12 o'clock on the dial, and again took it for a spin. When i did take it for a spin the temperature guage stayed on 12 o'clock for a while and then dropped to just above the blue on the guage, it stayed at this level until i got home, which i know wasn't the correct reading because the car was warm. I have tried the heating and the heating appears to now be working normal.

Basically i would like to know :

Have i done any damage to my car

Why is the temperature guage now all over the show

Dodgy thermostat ?

The system is getting pressure so i dont think its the water pump and i can't see any visible water leaks anywhere !!!

The car appears to be running as it always has done but obviously if its actually overheating then there is a serious risk of irreversable damage being done.

Like I said im not a mechanic, but, i dont mind getting the tools out, getting my hands dirty and LEARNING. EVERYBODY must start somewhere ...

Any help would be greatfully recieved.

Many Thanks

Lee

mcompact · « **Reply #1 on:** March 09, 2009, 06:34:06 PM »

A thermostat CAN be damaged by overheating, and there may also be more air in the system. Did you turn the heater controls to full hot before you refilled and bled the system? I'd try bleeding the system again with the front of the car elevated a bit; park the car on an incline with the front facing uphill.

djmitsilee · « **Reply #2 on:** March 10, 2009, 03:09:26 AM »

Thanks for the reply MCOMPACT !!!

Yes I did turn the heater controls to full hot before I bled the system, although I did have the heaters turned OFF ! Is this correct

I will get the ramps out today and try and bleed some more air out of the systen now that the car has been stood overnight.

You say that the thermostat CAN become damaged due to overheating, is it possible for me to test the thermostat ?

I have read how to get to the thremostat, and that its possible for me to test the thermostat using boling hot water and see'ing if it opens / closes. Is this true ?

Again many thanks for ALL the help guys ;-)

I am very greatfull that I found this site with ALL the helpfull forum users.

Lee

mcompact · « **Reply #3 on:** March 10, 2009, 06:56:09 AM »

The heater valve is electric, so the engine needs to be running or the key needs to be turned to the running position. You can test the thermostat but if I were you I'd just replace it. Why risk it?

djmitsilee · « **Reply #4 on:** March 10, 2009, 08:44:15 AM »

thx for the help MCOMPACT,

Think I will price up the thermostat and get that done, like you said, why risk it !!!

Gonna try and bleed it now, i'll let you know how i get on, again thks mate :-)

xwill112x · « **Reply #5 on:** March 10, 2009, 08:56:01 AM »

def. bleed your system, make sure you stop your leaks as well, thats what is cause of the air getting into your system.

other than that, i think your tstat is ok, you just have a big air-lock