: Trying to determine coolant loss source



tlarwa
12-15-05, 11:14 AM
First, I'm pretty sure I've read every post regarding the oil cooler... and, it's a 2001 non-sport w/ ~70K miles.

I had a coolant leak under the car one night ... puddled up when I pulled in the garage, and had some steam coming up from the hood on the passenger side. My thought was the HCV, but I didn't have a replacement handy, so I bought and added some stop-leak additive to see if it would temporarily stop the leak. Sure enough, the leak stopped. Problem is, I'm seeing some coolant loss now, but NO leaks. In fact, I ran the car in the garage for a while last night, at idle and while being accelerated (by my son), and didn't see one drop leak on the floor. I looked all over the engine compartment with a flashlight, too, but to no avail. I do smell some burning after I run the car, and I think it's a coolant smell (NO oil leaks, either, or any sign of an oil leak in the engine compartment). I have NO signs of coolant on the oil dipstick, my oil level is holding steady, and my coolant in the resevoir looks normal. Also, other than the usual condensation (I'm in Wisconsin), I don't see any unusual smoke from the exhaust pipe. The car is running beautifully ... no check engine lights or temperature lights, good oil pressure, good temperature readings, etc.

Any ideas on where my leak may be? I'm thinking maybe it's burning off while driving, so I'm not seeing a leak. Could it only be leaking while actually being driven (under load) vs. not leaking while sitting at idle/park? I'm not losing a ton of coolant, but it is losing a little (enough to indicate a leak somewhere). Could it be a leaky oil cooler? I plan to change the HCV this weekend, so I can eliminate that possibility, but I'd like to identify the source before I take it in to be fixed. Last thing I want to do is pay the dealer $80/hour to troubleshoot...

Thanks!

jesserb306
12-15-05, 11:26 AM
Does it leak when you shut the car off? I have a 2001 Sport and whenever I turned the car off I would smell coolant and it would be leaking. It was the HCV. Just a little experience though.

Jesse

AllenPacla
12-15-05, 12:00 PM
When you do the test run, turn on the heater inside and set it to warmest. This will show you better if there is any leak in the Heater Control Valve. Perhaps, the leak when you tested it is so little and is squirting towards the engine evaporating it even before it reaches the ground. Try turning on the heater inside the cabin and see what shows.

tlarwa
12-15-05, 12:11 PM
It is NOT leaking when I turn the car off, or when it is running and sitting still. It did, until I added the stop-leak additive, but that seemed to take car of the observable leak. That's why I can only think that it is "burning off" before it hits the ground. Wierd thing is, I don't see any signs of a leak anywhere in the engine compartment (at least not in the areas I can actually see). Can the oil cooler leak without it being "bad" (i.e. mixing oil and coolant)?? If so, would it make sense to just replace the cooler rather than reseal it, since I assume you need to rip the engine apart the same either way??

bengsxr
12-15-05, 01:22 PM
Well maybe it is a o-ring on the pipe the goes into the thermostat is leaking. because of where the thermostat is it will be really hard to find it if thats where the leak is. the thermostat is right on top of your engine under your plenium so it will all burn off before it ever gets to the ground.

bengsxr
12-15-05, 01:32 PM
I also seen that you have milky oil in another post is this correct. if so I might say this milky oil plus the coolant on the floor do you also smell oil burning on the engine cause if so I would maybe say you have a blown head gasket.

tlarwa
12-15-05, 01:33 PM
Hmmm ... good thought. I've never tried to replace the thermostat (or remove the plenum for that matter). Is this a job I can do? I just ordered the service manuals from Helm. I assume the procedure will be in there, correct? What is the correct p/n of the thermostat? I've read that there are some issues with there being a couple versions and one not fitting properly.

bengsxr
12-15-05, 03:04 PM
yeah it is a pain in the butt to do but you should be able to do it yourself just buy the one from the dealer and the two o-rings you will also need to buy.

upjeeper
05-26-06, 09:43 AM
When you do the test run, turn on the heater inside and set it to warmest. This will show you better if there is any leak in the Heater Control Valve. Perhaps, the leak when you tested it is so little and is squirting towards the engine evaporating it even before it reaches the ground. Try turning on the heater inside the cabin and see what shows.

maybe this is a stupid question but...
does the heat have to be on for coolant to leak from the heater control valve? my wife's catera seems to leak when the A/C is on