help! coolant leak! (with photo) - PeachParts Mercedes-Benz Forum

its_snowing · #1 12-02-2006, 04:10 PM

drat. i just got back from a longish drive, onyl to find that, after i parked the car and came back to it, that im leaking coolant, and fast. the level in the tank still looks good, so it may have just started.

im new to this - dont have my terminology down. its coming from something that looks like the oil pan, and it leaking out of the side of that. in the photo, the camera is looking up from the bottom of the car, from the passenger side. this is in the middle of the car, just behing the firewall area, and behind the exhaust pipe leading the back of the car. it is dripping out of something that looks like its supposed to be sealed.

my inexperience is preventing me from describing this properly, but maby the photo will help. whats going on here?

its_snowing · #2 12-02-2006, 04:17 PM

ps. that is NOT the oil pan, by the way, its just the best way i could describe what it looks like.

Biodiesel300TD · #3 12-02-2006, 04:18 PM

That is your transmission fluid pan in the picture. Your leak is most likely comming from a heater hose on the firewall in the engine bay, and the coolant is leaking down to where you are seeing it. Open the hood and look at the heater hoses and monovalve on the firewall. Or try following each hose from the radiator to locate the leak. I wouldn't drive untill you find the leak, you don't want to loose all your coolant, or the repairs get REALLY expensive. Once you find the likely leaky spot wipe everything down and see if you can find exctly where the drips are comming out.

its_snowing · #4 12-02-2006, 04:26 PM

thanks!

however, i had already checked the hoses around the monovalve area, and could see anything obviously leaking. the whole are is dry. the leak would seem to be coming from somewhere underneath. strangely, it now seems to have stopped, and it appears that the leak was strongest right after i shut the car down, and has now fizzled more or less out.

Biodiesel300TD · #5 12-02-2006, 06:01 PM

Wipe everything down and keep an eye on it. If may have sealed its self for now, but I'm sure it will come back.

Brian Carlton · #6 12-02-2006, 06:08 PM

Check the area around the monovalve again and be sure that it's fully dry.

Then, check the overflow line that comes off the expansion tank. It's possible that this line let some coolant out, if the tank was overfilled, and it can end up anywere on the bottom of the vehicle.

If neither of the above are the culprits, you are looking at a leak in the heater core.........something that you really don't want to know...........

vstech · #7 12-02-2006, 06:14 PM

if you have not been driving the car, the heat and pressure has gone down, so that is mostlikely why the leak fizzled down. you can get a pressure pump up kit from autozone, pump up the pressure to 10 or so and then look for where the leak is.
John

its_snowing · #8 12-02-2006, 07:01 PM

ill have to check again when the pressures pumped up, then. if, hypothetically, the heater core needed to be fixed, replaced... what does the cost of labor usually run on that?

mybenz123 · #9 12-02-2006, 07:09 PM

Its snowing.

You might also want to change that coolant to the
proper recommended coolant.
Zerex-o5 or the like.
Lotsa info when you use the search function.

Louis.

dmorrison · #10 12-02-2006, 07:16 PM

Check your heater core in the dash. Turn the heat and fan on and smell the vent output air, if it smells like antifreeze then your heater core may have deleloped a leak. Consider radiator leakstop to fix it, It a big job otherwise.

Dave

t walgamuth · #11 12-02-2006, 07:36 PM

after checking the heater hoses,

i would suspect the lower radiator hose clamp loose, and the short hose between the thermostat housing for loose clamps.

i would think if the heater core leaked it would go inside the pass compartment.

under the hood a leak can be blown back pretty far from the fan on the engine.

tom w

dmorrison · #12 12-02-2006, 08:47 PM

Quote:

Originally Posted by t walgamuth

after checking the heater hoses,

i would suspect the lower radiator hose clamp loose, and the short hose between the thermostat housing for loose clamps.

i would think if the heater core leaked it would go inside the pass compartment.

under the hood a leak can be blown back pretty far from the fan on the engine.

tom w

If the heater core leaks it can drip through the same condensor drain that the evaporator uses. Now I will not disagree with you on the variations that a leak can have, and you may be right. But by what we have been shown. The fluid up high next to the tranny and not on the bottom of the tranny pan. I figure it is either the heater core or the -heater core tubes going through the firewall- to the rubber hose connection. Check all 3 of them as well as the mono valve connections and housing ( for cracks).

Dave

its_snowing · #13 12-03-2006, 02:17 PM

update -

while running the car at operating temp, with the heater ON, i couldnt get it to leak. hoses around the monovalve were warm, and the heat worked. there are no unusual smells in the cabin at all. after shutting off, opened the coolant reservoir and it popped open pretty forcefully, indicating that theres still a good deal of pressure. also, no hoses in front of the firewall were noticeable leaking, or even wet at all.

any more ideas? im going to bring it in on monday. the stress of even the possibility of a heater core is ruining my weekend.

#14 12-03-2006, 02:48 PM

Quote:

Originally Posted by its_snowing

any more ideas? im going to bring it in on monday. the stress of even the possibility of a heater core is ruining my weekend.

I think you would be smelling coolant if the heater core was leaking. I really doubt that the core is the problem. My best guess is still a small leak in a hose someplace.

kerry · #15 12-03-2006, 02:54 PM

I'm agreeing the Brian. It could be coming from the expansion tank.