Radiator leak from hose to the left - BMW Forum

delerdelarosa · 10-23-2003, 11:35 PM

Hi. I have a 1984 318i and am currently experiencing prestone leaking from a hose attached to the left of the radiator. I've attached an image to illustrate my problem.

Whenever I turn the engine on, prestone drips from this hose and eventually I have to stop, wait and refill with anti-freeze directly in the radiator (I lose about half a litre every 15 minutes) since I don't have an overflow tank on the 318i (4 cylinder).

Does anyone have an idea as to why this is happening. I'm thinking it has something to do with my thermostat not working properly and not opening, or maybe I'm just being foolish Thanks in advance!

BMWJNKY · 10-24-2003, 01:50 AM

Make sure the hose fits sugnly on the overflow outlet. If the hose is tight have your raidator pressure tested to make sure the filler neck istn't cracked, which in this case sounds like the problem. Most repair shops do this, and if there is a check out fee it is usually take off if you have that shop do the repair work. Thats how the shop I work at does it. Hope this helps, and if the radiator is broken it isn't going to be cheep to replace, usual cost is about $200+ for a Behr replacement radiator.

delerdelarosa · 10-24-2003, 07:57 AM

Thanks AJ.

The hose fits snugly into the overflow exit. I can't see any visible cracks but it might be in the interior.

I'm bringing it to a contact who specializes in older bimmers tomorrow and will post an update.

Mach 5 · 10-24-2003, 10:21 AM

My old 84 318i did this I just had to replace the radiator cap about $25 I think. My cap would no longer hold pressure and would then leak out of the overflow tube. If you do need to replace the radiator buy the Behr part, I replaced mine with a cheap after market, due to accident by PO, and regretted it as it was nowhere near the quality of the OEM part.
Ben

delerdelarosa · 10-24-2003, 10:45 AM

That's not a bad first step. I'm gonna pick up a cap first and try it out tonight.

Also, is the rubber washer/seal just inside the radiator mouth supposed to be bigger, or should it fit in snugly?

Mach 5 · 10-24-2003, 12:07 PM

The Rubber washer had deformed on mine. When new the washer fit on the cap snugly. I tried to buy just the washer but it came as part of the cap assembley. And with the milage that I had a new cap was a precaution, I also noticed the cap had been redesigned and did not match the original.
Ben