Problem with leaking coolant

JENNA408

MEMBER
1998 CADILLAC DEVILLE
150,000 MILES

The car has been leaking coolant and overheating for quite some time. I have replaced the water pump, radiator, coolant resevoir, thermostat and all hoses and gaskets. The water WAS leaking from the water pump gasket, but since replacing it has started to leak directly in the center of the car, straight onto the ground. Attached is a photo I took laying on the ground underneath the car, I am pointing to the piece that is leaking (the square black thing with the hole in the center and a silver part underneath it). Any idea what this part is or why it's leaking?

Image (Click to make bigger)

Friday, September 2nd, 2011 AT 10:40 PM

2 Replies

JACOBANDNICKOLAS

MECHANIC
110,143 POSTS

You are pointing to a mount. The coolant is leaking from above that and on to it. Get a pressure tester, most parts stores will lend them to you. With the engine cold, remove the radiator cap, install the hand held pump, and pressurize the system. At that point, you can look for leaks. NOTE: If you still can't find it, they make a dye that you can add to the coolant and see under a black light.

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Sunday, August 18th, 2019 AT 10:05 AM

FACTORYJACK

MECHANIC
4,159 POSTS

When you say you replaced ALL hoses, did you replace the two silicone(green) hoses that are on the back side of the crossover? A leak in this area could be coming from loose hose clamps at those hoses, or leaking from the crossover. A leak at the crossover, is most likely to be located at the back side of the engine, under the egr valve area, where the crossover meets the block. Visual access is almost nil, unless you go down in that area with an inspection mirror and a light.

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Sunday, August 18th, 2019 AT 10:05 AM