Mystery coolant leak

[Huntervf]

For the past three days I've found patch of coolant under the extreme driver side front of the car. The center of this patch lines up almost perfectly with the drain **** on the radiator. And no that's not where the leak is

Crawling underneath the car I can see fresh coolant dripping off a trio of hoses that connect in that location. I don't believe these are coolant hoses however, and the lower core support itself is wet in that are but I cannot determine the exact location of the leak. What makes this whole thing strange is that I wiped the whole area clean, waited about 1.5 hours while I was doing other work and checked again. Completely dry. Started the car and let it run for about 40 minutes. The fan kicked on three times so the car was defintiely up to full running temp and the cooling system was well pressurized (i.e. the upper radiator hose felt very firm). It remained completely dry the whole time it was running. No leakage, no drips, nothing. I checked it a couple hours after I shut the car off...dry. And this morning low and behold there's another patch of coolant, coming from the same area. Overall it's not a huge leak, maybe enough to fill a shot glass half way (but spread out over the ground it looks a lot worse), but I just can't figure out where it's coming from. I examined the end tanks as best I could along the seams and I found no leakage there, however I couldn't examine the very bottom section of the end tank on the driver side where it meets up with the lower core support. Regardless, it should leak worse when the system is pressurized, yes? Basically for a period of 3-4 hours I kept a close eye on the whole area under the car and it all remained completely dry. Anyone have any thoughts on this one?

 

[Mr Anonymous]

It's kind of typical around here when an end tank just starts to leak. Hot it's fine, but below ~35 degrees it'll start weeping. I drove over 15K on my '92 with that, having to add about a cup of coolant every 3-4 weeks until the warmer weather.

 

[SHOtimer]

My upper radiator hose leak would manifest itself in that way also. Would leak from where it connects to the radiator but only on the bottom of the hose and it would only leak when cold. Once it heated up no leak.

Doug

 

[SmyleySho]

Hmm I have the exact same problem. I think the main problem is where it leaks on the (what appears to be) vacuum lines on the driver side and the fan motors are in the way to pin point it. I will be removing my radiator tomorrow and have it pressure tested. I'll post the results after Im done.

 

[sdpatt]

It is likely that the leak is from the rubber seal between the metal tube section and the compositite end tank. Another possibility is that the end tank has cracked, but that type of breech usually displays itself when the system is under pressure. The end tank seal leak usually shows up as the system cools down after the engine has been shut off.

The fix is either a new $100-$150 radiator (some can be had with lifetime warranties) or a removal, repair by a radiator shop and replacement. The new radiator is easier, quicker and not much more costly in the long run.

 

[Huntervf]

Thanks for the info folks Makes sense...this leak didn't start until we got some cold weather out here. Looks like a radiator is in my future then...geez with a new water pump, t-stat and sending unit I'd say my cooling system is going to be pretty much new!

 

[SmyleySho]

I removed my radiator today and found that I had two leaks that were intermittent. I didnt even need to have it pressure tested. I found that on the driver side tank had a crack about one inch long. It is located about 3in. down from the top of the plastic tank, but thats not where the leak was bad. The second leak was comming from the same side of the tank, but it appears that the tank was loose from the aluminum coils. My guess is that when the car had gotten warm, the tank expanded and stopped the leak. Anyway thats what I found. Hope this helps......

 

[97sho-mann]

Hide and Seek Leak?

OK , I must be the odd man out.. I had a very small leak that just couldn't be found. (put it on the lift, everything on top and bottom, dry)
That was a few months ago when it was warm. Flushed the system and no more problem.
This morning (14 degrees outside) What I call "COLD"
I have steam with antifreeze smell coming up near the
serpentine belt, so I figure =Water pump problem?
thermostat problem?....Put it on the lift this afternoon, Nothing! everything is dry ...Beats me..I'll continue to look for the "Mystery Leak".
(This is on my 93 ATX not the 97)

 

[Huntervf]

That particular leak probably is your water pump...usually what happens is that the coolant drips down onto the y-pipe and vaporizes. As such you never see the leak.

As for my leaks...well aside from just a couple instances since November it's been dry. The few times I've found coolant it hasn't been much, but it's happened only after sitting overnight and doesn't seem related to temperature. And now my wife's 93 is leaking too, and it's intermittent as well.

Ah the joys of owning 2 SHO's...

 

[97sho-mann]

Hide and Seek Leak?

Thank God Antifreeze is still cheap...
I'm coming up on my 120k service, so I guess I'll throw
in a new Water Pump , Thermostat and Radiator while it's
all apart. fwiw I drove Mean Green (93) Today..no steam
no leaks.. It's a GOOD DAY.

 

[qiksho]

That particular leak probably is your water pump...usually what happens is that the coolant drips down onto the y-pipe and vaporizes. As such you never see the leak.

As for my leaks...well aside from just a couple instances since November it's been dry. The few times I've found coolant it hasn't been much, but it's happened only after sitting overnight and doesn't seem related to temperature. And now my wife's 93 is leaking too, and it's intermittent as well.

Ah the joys of owning 2 SHO's...

Glad I am not the only one with SHO's that leak coolant in the winter. I just replaced all hoses, and radiator on the 92, so it doesn't leak anymore.

But now the 93 is leaking from the upper radiator hose...This cold weather really tests your cooling system.

 

[todras]

Good luck. I've had a leak forever. It's so slow I just top everything off once a month. I replaced the radiator when I bought the car and replaced both upper and lower hoses. Can't see where it's coming from and it's so slow I just gave up throwing $ at it. No I'm just throwing $5 a month into coolant.