Mystery coolant Leak

[Silver Fox]

I am getting two or three coolant drips on my garage floor after driving the Buick. The drips are coming out of the hole on the torque converter/flywheel inspection plate.

I put a pressure tester on the radiator and put the car up on a lift. Here is what I found.

On the driver's side of the car, I could see coolant of the top outer edge of the oil pan, from the front of the engine to the rear. The coolant appeared to be going to the back of the oil pan and running down and out of the inspection plate.

The passenger side of the oil pan was dry.

All freeze plugs and coolant drains on the block looked dry (but I could not see clearly behind the motor mount on the driver's side).

The water pump (and weep hole) were dry.

No intake gasket leaks noted.

No leaks from the heads were seen.

None of the hoses/heater control valves/etc were seen leaking with the pressure tester on the it.

Any ideas on what else to look for?

Thanks,

Rob

 

[driveshaft man]

Could be freeze plugs on back of the block,that you can't see, behind flywheel.A little Alumaseal will buy you some time.I would round up some new brass freeze plugs and do all at once at earlist convenience

 

[Silver Fox]

Could be freeze plugs on back of the block,that you can't see, behind flywheel.A little Alumaseal will buy you some time.I would round up some new brass freeze plugs and do all at once at earlist convenience

The leak has been going on for a while, so when I threw in my new PTC converter a few weeks back, I replaced all the freeze plugs on the back of the block. I checked them out real good today - they were all dry.

Rob

 

[Silver Fox]

On last thing - the drips of coolant do not show up on the floor until 24-48 hours after I park the car.

 

[Phoneguy]

On last thing - the drips of coolant do not show up on the floor until 24-48 hours after I park the car.

I suggest not parking the car for 24-48 hours :biggrin:

Seriously though, place a paper towel behind the motor mount and see if it gets wet, if not move to another area and try again. HTH

Bryan

 

[Pronto]

Try the coolant dye. Clean up the block and see where it's comming from.

 

[Silver Fox]

I replaced the heater control valve per recommendation of Nick at ArizonaGN.

Looks like the mystery leak is gone. I have only driven the car twice since replacing the valve, so I will be keeping an eye on it for the next few drives.

Thanks Nick!

Rob