I have recently, within 2010 replaced most all the plastic coolant parts that I know of due to leaks that developed. These include the thermostat housing / cap and thermostat, coolant reservoir and one small plastic line from he coolant reservoir to the thermostat housing.

Right now it is losing coolant enough to have to top it off once or twice a week. I don't see anything on the ground and don't readily see where it could be leaking. I am going to get a good look at it this afternoon as I have been busy. I wanted to know what anyone else's experience may have been along these lines. Or what else I may look for.

Any advice is well appreciated,
Pat

 

Headgasket? Was the car overheated?

 

The simple solution is to rent a set of pressure test equipment from you neighborhood auto parts store and pump it up while the engine is cold. With the leak you describe there is no question that it would show up in one minute flat.

 

Mine is driving me crazy too. I have to add about 12 ounces every 1000 miles.

Take a look on top of the block where the water pump bolts up. Is there a little pool there? That seems to be where mine is collecting then it evaporates off.

Ken

 

Sinister:
That sounds like you have a crack in the thermostat housing. Time to get the aluminum replacement. See archives for the way to get the old one off with the crowsfoot wrench.
Or better yet, someone suggested breaking the old plastic one, getting the bolts out. then replacing them with socket head cap screws.

 

I replaced all those pieces up front and on top, thermostat and housing/cap.. They are new and clean. That's what was confusing. I could not see anything and it ran fine. If it were a head gasket and losing the amount of coolant I am loosing it would not be running.. Right now the engine runs great.. I pulled all the covers off the engine and found it leaking under the coolant reservoir above the tranny. That funky "norma" connector.

To replace the connector do you have to replace the entire hose group??

 

norcaldiesel-
I was hijacking your thread a lil to reply to Sinister- sorry!

As to your problem, I am puzzled too. If it aint laking onto the ground, then it just about has to be going thru the engine. It could very well be leaking that much into the engine and running fine, though. My XJR had that symptom for a few weeks before the engine started showing white steam at startup. Look for 1 plug to be very clean.

 

I thought that mine was leaking at the above mentioned hose that comes out of the coolant tank but after a closer look I saw the problem: a tiny hairline crack on the tank (underneath on the side) that made it look like it was the hose/connection and due to the heat the coolant was evaporating. Take a GOOD look at that tank!

 

My reservoir was leaking down in less than a week and there was never a drop on the floor. The coolant was dripping onto the catalytic converter and vaporizing.

Use a pressure tester!

 

I did that last year when I did the chains, tensioners, water pump and hoses. I've been over this thing with an inspection mirror and a flashlight for hours both when cold and hot/running.

My next trick is the pressure tester.