Radiator neck leaks when hot

[mdelorie]

Hey folks,

 

Been a long long time since I posted here, but I'm in a bit of a bind here with my Lumina. Once the engine becomes hot, the radiator starts leaking from the upper neck right along the seam joining the two halves together. It's fine up until the engine hits past half-way on the temperature guage (about 65, 70 degrees C?).

 

Anyways, I'm looking at this thing, thinking there's got to be a way to seal that up without replacing the entire rad. It's a plastic neck, and if you apply downward pressure on the neck, you can see the coolant start to spill out a little heavier.

 

Any suggestions? I'll replace the rad if I have to, but I'm not thinking it's going to require that. Rubber cement? epoxy? some sort of tape?

 

Here's a picture describing the problem. Like I said, it leaks right along the seam of the two halves of the neck.

 

 

Thanks guys

 

[Crimson Fury Z]

on the driver side? loosen the pressure cap and see if its a pressure leak, mine leaks from the driver side around the same area, and loosening the cap stopped it. i will end up getting a new radiator.

[mdelorie]

I definitely think it's a crack in the neck... although I think I'll try replacing the cap first. I'm also going to replace that old spring clamp on the hose.

 

Like I was saying, you can see the coolant leak out of the neck when you apply downward force to it.

[chadz34]

I definitely think it's a crack in the neck... although I think I'll try replacing the cap first. I'm also going to replace that old spring clamp on the hose.

 

Like I was saying, you can see the coolant leak out of the neck when you apply downward force to it.

Time for a new rad then.

[mdelorie]

Ugh.... that's what I was afraid of.

 

So, if that's the case, what're my options? I know next to nothing about rads other than being able to replace it with another stock. Are there options for W-bodies? Something about quad-core or aluminum versus copper rads or something to that nature? The transmission coolers are integrated into these rads I believe? and they sit right behind the A/C condenser. Am I right on all this stuff?

[chadz34]

Ugh.... that's what I was afraid of.

 

So, if that's the case, what're my options? I know next to nothing about rads other than being able to replace it with another stock. Are there options for W-bodies? Something about quad-core or aluminum versus copper rads or something to that nature? The transmission coolers are integrated into these rads I believe? and they sit right behind the A/C condenser. Am I right on all this stuff?

Just get the stock replacement.You can get it at AutoZone or stores like that. There's nothing really special to look for in a rad other than it's the original replacemt for that car.

[5speedz34]

They are pretty easy to replace.

 

Take the fans out, and then some bolts and take the radiator out. I would either get one from the yard, or have your current one rebuilt.

[GIANT MOTH]

CRACKED!!! NEW Radiators are not terribly expensive. Check your prices locally and on the web.

[GnatGoSplat]

Could be just me, but it doesn't look like just the neck, that pic looks like there's a big vertical crack going all the way up to the top of the rad.

You can replace just the sides, I think the service manual explains how, but it's not worth the effort and I don't think you can get just the sides from a regular auto parts store.

 

[mdelorie]

I see what you mean about the crack all the way up, but I think the picture's just deceiving in that way. I was driving fairly fast while this leak began, and it sort of got coolant all over the place. The neck is the only place that liquid actually originates from.

 

Well, being the improvisational bastard I am, I'm not going to give up on this sucker yet. Once I get it all home and everything (I'm moving in a few weeks and fortunately the Lumina will ride on a flatbed trailer behind the truck), I'll drain the coolant, maybe take the rad out, and see what I can do to seal it up. I'll post pictures and details on my success or failure.

 

Thanks guys

[mdelorie]

so I pulled the rad, had the local radiator shop replace the left tank. Cost me 80 bucks all in all, plus I got the chance to clean out the compartment where the rad sits... amazing the crap that can build up.

 

The guy at the rad shop says it's quite common for that side to crack, as it's the side that the thermostat is on and is subjected to higher pressures every time it opens.

 

Makes sense to me....

[Bossman429]

Well, it's a little late for me, but I was going to say you can just replace the tank on that side. A new radiator would have run around $200, or more. Replacing the tank is the way to do it on a budget.