another radiator prob

[mattyb]

my rad is leaking from a small round bit of plastic just under the top hose on the left. ive searched the archives but cant find reference to this. My indy says to drain the level when cold and remove the top hose and reach in and smear some sealant around the small round bit from the inside.any experience out there on this? if so what kinda sealant? silicone maybe? thanx in advance.

[Kalevera]

my rad is leaking from a small round bit of plastic just under the top hose on the left. ive searched the archives but cant find reference to this. My indy says to drain the level when cold and remove the top hose and reach in and smear some sealant around the small round bit from the inside.any experience out there on this? if so what kinda sealant? silicone maybe? thanx in advance.

Matt...if the radiator's cracked or broken where it's not supposed to be, it may be time for a new one. Repairing them is tricky business...and once the integrity of a plastic tanked radiator is compromised, it's only a matter of time before the thing shatters on the freeway. RTV isn't suitable for any part of the cooling system; the stuff breaks off and clogs the pisser, overheating the engine.

Sorry to intimate that there's little that can be done, but with plastic tanked radiators, that's just the case. This is why Zionsville started making 100% aluminum radiators for 3 series cars. They considered making them for the E34, but they claimed no market existed for it.

They could certainly sell me one

best, whit

[uscharalph]

"This is why Zionsville started making 100% aluminum radiators for 3 series cars. They considered making them for the E34, but they claimed no market existed for it.

They could certainly sell me one."

I'd buy one and I just replaced mine

[mattyb]

oki doki. seems id buy one too. thanx anyways for the replies.

[Cambridge]

There are two plugs molded into the plastic on the left side. Evidently for some radiators this is where the fitings for connections to the transmission would be (not used on 540i).

Here is a picture of my old radiator as I pulled it out:
Old Radiator

You can see the JB Weld epoxy that I applied to hold it together until I could have the new radiator shipped to me. You can see that the epoxy covers that circular plug you describd. The epoxy looks very ugly but it held until I could do the replacement. I applied the epoxy to the outside so as not to get any into the coolant.

Interestingly, just as soon as I repaired that crack, others began to appear and leak. By the time I finally got the new radiator installed I had repaired several leaks.

When I was able to install the new radiator, I was able to take a flashlight and take a good look inside the old one. I could see that the plastic was crumbling and flaking off inside. I could break off pieces with just my finger tip. Frankly, I'm suprised the radiator just didn't blow apart under pressure at highway speed. That would have been very bad. I think I just barely dodged a bullet. (...which is why I don't recommend the patching idea )

I took some pictures of the repair procedure. Maybe they'll be of some help:
Radiator Replacement

[mattyb]

that was exactly it.

[mattyb]

the epoxy weld resin. how do u apply it, ill have to do it for now.

[mattyb]

those little plugs look like they have a small hex head on them, did u by any chance try and unswcrew the bottom one to see if there was a thread on it