How to tell if you have a crack or hole in the radiator?

[bodyart27]

This is actually for my 97 S600 - but you guys are SO good I thought I'd ask. I'm pretty darn sure I have a tiny crack or hole somewhere near the bottom of the radiator (could be the plastic end cap that is crimped to the bottom) near the lower control hose. I've replaced the lower hose, cleaned up the clamp, moved the clamp around and reclamped and I still a small leak.

When I say a small leak, after two weeks of sitting in the garage, I'll have a tiny little path of fluid heading to the back of the car (sealed garage floor - not absorbing into the concrete). The resevoir really isn't impacted much at all (so far - can't tell).

So I'm trying to be 100% sure it's not the hose connection (I think it's the cap on the bottom of the radiator leaking or a pin hole).

How do you tell - dye and a special light? It's a $500 part (radiator) so I want to be darn sure before I do this.

[Hatterasguy]

Knowing you its probably really, really clean? Can you see any dried coolant? When you drive it it should start to leak more then dry up.

[Brian Carlton]

With a leak that small, you'll need a pressure tester to put 17 psi on the system and then carefully look around for the drip. You may need to wait 30 minutes to 1 hour to find it. The underside of the engine/radiator must be clean.

[barry123400]

Once you find the leak and are sure it is the radiator.
Why not take the rad out and take it too a reputable radiator repair shop for them to have a look? Another source since your car is not really that old by this sites members standards is to check salvage yards for a good looking used radiator? With a clean looking internal core.
If you find a car in the wreckers with the cooling system still full that would probably do it well. Another option is the radiator may be available as an aftermarket replacement at far fewer dollars. If you feel uncomforatable with that just mail me the difference.
There are also parts hunting sites I have used on the web where your request goes to hundreds of yards.
Since you are accumulating a small puddle when sitting a rad pressure enhancing gauge should locate the leak as mentioned by Brian Carlton. Watch for fluid travelling from the water pump down the hose especially. One of the bigger automotive chain parts places may have a nominal or free rental program for the tool itself. I hope it is not the radiator itself but it is quite possible it is.

[jbach36]

Whole is spelled "hole", unless we're talking about the whole car, in its entirety, that is.

[vstech]

ahh, ok.
anyway, you should be able to get a cooling system pump up tester at any good auto parts supplier. autozone has a rental system, so you buy the part, then return it when you are done.
I got my set from a snap on truck.
pump up the system, start looking for coolant escaping.
John

[nota]

there are rad leak stopers
one of the best is wallnut shells
ground very fine

caddys use the stuff in new non leaking cars
to prevent leaks so no worrys about it gumming anything up
at a few bucks a tube sure is way cheaper then a new rad

btw I donot own a caddy
but my fiero has a caddy northstar v8 in it

[nhdoc]

Originally Posted by nota

there are rad leak stopers
one of the best is wallnut shells
ground very fine

caddys use the stuff in new non leaking cars
to prevent leaks so no worrys about it gumming anything up
at a few bucks a tube sure is way cheaper then a new rad

btw I donot own a caddy
but my fiero has a caddy northstar v8 in it

Yeah, then once the leak stops you put a few chipmonks into the radiator to eat the walnut shells, then a cat to catch the chipmonks, a dog to chase the cat out...

Forget leak stops...the leak is probably in the seam between the plastic and aluminum parts. It's pretty common. It will leak when cold but not warm. Eventually it will leak all the time. I have heard it can be repaired but don't know this first-hand and based upon my exam of the radiator the joint does not look like they designed it to ever be opened again.

[nota]

ground wallnut shells WORK
ESP if used at the weep stage
they will prevent the weep from progressing to a leak
spend $5 now and save $500 on a new rad

btw chipmonks donot like shells just the nuts

Why not replace the bottom hose and see if it stops? If that doesn't fix it, toss in a new radiator.

[bodyart27]

I actually have replaced both hoses (I was replacing the thermostat - so might as well).

Intersting comment about it leaking when it is cold - that does fit what's happening. I thought it may be evaporating when hot and that is why I wasn't seeing a leak (plus when the engine is running the fan is blowing on it aiding evaporation). It's definately a slow leak, but overnight on the sealed garage floor, there will be a spot that will grow during the week if I don't put a rag under it.

I was also suspecting the crimped on cap at the bottom.

Been so busy lately I haven't had a chance to dig into this more.

[JimmyL]

Originally Posted by Brian Carlton

The underside of the engine/radiator must be clean.

Uhm, remember who you are talking to here. I ate my barbecue sandwich off of his SD engine at the last GTG......

[Brian Carlton]

Originally Posted by JimmyL

Uhm, remember who you are talking to here. I ate my barbecue sandwich off of his SD engine at the last GTG......

Yep.........right...........I forgot about that...........that's a showroom piece.

[bodyart27]

hmmm

I've never taken the S600 on a road trip. IT only covered 600 miles last year. Maybe I'll take that to the next RLeo GTG!

Then you can decide if the V-12 engine bay compares up to the 5-cylinder diesel engine bay.