E36 M43 motor water leak

[Solo Man]

Hi, need some advice as i am at wits end with the recurring water leak on the M43 motor i am busy fixing. At the back of the head in between the head and the firewall there is a small plastic elbow with a junction that feeds the heater pipes. This pipe goes into the cylinder head about 15mm deep and seals with an O-ring. On this particular head the previous plastic pipe was leaking for a long time and the water has corroded the opening with the result the O-ring on the new plastic pipe cannot make a watertight seal. I have tried a larger diameter O-ring but it still leaks when under pressure. I am contemplating using Pratley Puttey plus the oversize O-ring to seal this but am not sure which product to use as they seem to not like prolonged heat. Any other products i can try in this application that you have tried in a similar situation and gotten positive results??

 

[racing snake]

your best bet will be to get the hole welded up and redone properly.

 

[Solo Man]

Hi Snake, nice to hear from you! The removal of the head is the last resort but at this stage i think i will solve the problem by fitting a new O-ring and some gasket former. Have discussed the problem with family and friends and had another good look this morning at the opening where the O-ring seats and it seems OK. When i took out the pipe this morning i noticed that the O-ring (slight oversize i put in yesterday) had some damage and cuts due to me having to use the two screws to press it into the opening as you cannot get your hand in there to press it in. Eventually got a better access to the bolts/pipe by lying under the car and working from there. At least when i used the standard size O-ring and the sealer i could get the pipe into the opening and fasten it without damaging the O-ring. Going to leave it to set and will see if it works tomorrow. If it still leaks then i am going to try the next size O-ring and work it in gently without damaging the ring.

 

[mrtwizter]

see this post from other BMW Fanatics

http://www.bmwfanatics.co.za/showthread.php?tid=45849